Space elevators?!? [Archive]

eburacum45

03-24-07, 06:34 AM

Do you actually feel gravity inside the orbital station of a space elevator?

I could be wrong but I assume that if you lengthen the cable then you experience a outwards force any ID on how far you should travel from GEO to experience 1G?

Starting on Earth, you will feel one gee at the surface, of course. As you go up the elevator that gravitational pull will decrease until you are in zero gee at the geostartionary point. Gravity will fall off with the inverse square of the distance, so it will decrease quite rapidly in the first six thousand kilometers or so to a quarter of a gee, then more slowly after that, but there will be some gravity right out to just before the geostationary orbit.

That is why in my model I have included a rotating section to provide artificial gravity at the geostationary point.

As you go beyond the geostationary point onto the counterweight part of the tether you will experience an acceleration away from the Earth; some designs incorporate a long counterweight tether the same length as the Earthward component, and the outwards force at the end would equal one gee.
Using such a tether would actually allow propellant free launches from the far end; simply travel to the end of the tether and let go, and you will be flung outwards towards your destination at an initial velocity of 9.8m/s.

orcot

03-24-07, 07:18 AM

flung outwards towards your destination at an initial velocity of 9.8m/s.
To the moon perhaps but wouldn't you get a 30m/s bonus if you leave the earth system and went for mars for example.

I wonder if the elevator would have it's own little cable so the climber stays around the main cable but the passenger cabine rotates around the actual climber perhaps you would have artificial gravity. It would proberly only work ones outside the atmosphere?

Singularity

03-24-07, 07:24 AM

Space elevator is a conspiracy to keep humans away from cheap space travel

orcot

03-24-07, 08:12 AM

Space elevator is a conspiracy to keep humans away from cheap space travel

You figured it out? Well your totally right afther the door closes you yust get shaken around a little bid and then they take you to the studio basement (you know the same way like airplanes)

eburacum45

03-24-07, 11:47 AM

I wonder if the elevator would have it's own little cable so the climber stays around the main cable but the passenger cabine rotates around the actual climber perhaps you would have artificial gravity. It would proberly only work ones outside the atmosphere?
I don't think it would be worth doing
- any passengers in the elevator would feel Earth's gravity at almost full strength way outside the atmosphere, and would never experience real zero gee till they got to the geostationary orbit position.

A rotating segment might introduce an imbalance to the elevator, and would itself be imbalanced by the gravity field of Earth. You might figure out a way to do it, though.

Singularity

03-24-07, 11:55 AM

You figured it out? Well your totally right afther the door closes you yust get shaken around a little bid and then they take you to the studio basement (you know the same way like airplanes)

Talking about airplanes here is an example,
http://home.cfl.rr.com/bbloss/mustang/index_files/image001.jpg

http://home.cfl.rr.com/bbloss/mustang/index_files/image004.gif

http://home.cfl.rr.com/bbloss/mustang/index_files/image012.jpg

http://home.cfl.rr.com/bbloss/mustang/

Syzygys

03-24-07, 12:36 PM

The whole space elevator is interesting as an idea, but it is unrealizable...

What happens when a hurrican comes by? Do you know that there are 100+ miles winds up there even without a hurrican??

orcot

03-24-07, 12:53 PM

In the atmosphere, the risk factors of wind and lightning come into play. The basic mitigation is location. As long as the tether's anchor remains within two degrees of the equator, it will remain in the quiet zone between the Earth's Hadley cells, where there is relatively little violent weather. Remaining storms could be avoided by moving a floating anchor platform. The lightning risk can be minimized by using a nonconductive fiber with a water-resistant coating to help prevent a conductive buildup from forming. The wind risk can be minimized by use of a fiber with a small cross-sectional area that can rotate with the wind to reduce resistance. Ice forming on the cable also presents a potential problem. It could add significantly to the cable's weight and affect the passage of elevator cars. Also, ice falling from the cable could damage elevator cars or the cable itself. To get rid of ice, special elevator cars could scrape the ice off.

One rather recent discovery is that high wind speeds can flatten the elevator cable horizontally across the surface of the Earth perhaps a hundred kilometers.[citation needed] Surprisingly, the stress on the cable is not significantly increased (since the elevator is tens of thousands of kilometers long the percentage increase is tiny) and no major damage is predicted.

(wiki) (http://en.wikipedia.org/wiki/Space_elevator#Weather)

Janus58

03-24-07, 01:26 PM

5Where do you get that :confused: picture from)

I created it last evening.

draqon

03-24-07, 01:36 PM

hypersonic?

Janus58

03-24-07, 02:10 PM

Starting on Earth, you will feel one gee at the surface, of course. As you go up the elevator that gravitational pull will decrease until you are in zero gee at the geostartionary point. Gravity will fall off with the inverse square of the distance, so it will decrease quite rapidly in the first six thousand kilometers or so to a quarter of a gee, then more slowly after that, but there will be some gravity right out to just before the geostationary orbit.

That is why in my model I have included a rotating section to provide artificial gravity at the geostationary point.

As you go beyond the geostationary point onto the counterweight part of the tether you will experience an acceleration away from the Earth; some designs incorporate a long counterweight tether the same length as the Earthward component, and the outwards force at the end would equal one gee.
If the outward tether is the same length as the inner tether, then the outward force would be about 4% of a g.

Geosync orbit has a 42,300,000m radius, twice that is 84,600,000m.

Centripetal acceleration can be found by:

a= 4pi²r/T²

where T = 85536 sec.

this gives an answer of .456 m/s²

Substract the force of gravity for this distance (.056 m/s²) and you get 0.4 m/sec² which is close to 4% of a g.

Using such a tether would actually allow propellant free launches from the far end; simply travel to the end of the tether and let go, and you will be flung outwards towards your destination at an initial velocity of 9.8m/s.

You would leave with the radial velocity. This can be found by:

v= 2r pi/T

v= 2(84,600,000m)(3.14)/85536s = 6214m/s. Which is twice the escape speed from that altitude, which leaves you a net gain of about 3km/sec after breaking free from the Earth. This just about what you need to enter a transfer orbit to Mars.

Janus58

03-24-07, 02:14 PM

To the moon perhaps but wouldn't you get a 30m/s bonus if you leave the earth system and went for mars for example.

Yeah, but you get that no matter how you launch fron Earth.

Singularity

03-24-07, 02:24 PM

Helium filled SpaceShip anyone ?

http://msnbcmedia4.msn.com/j/msnbc/Components/Video/040518/050418_ascender.hlarge.jpg

Do u still want the Elevator ?

http://www.msnbc.msn.com/id/5025388/

draqon

03-24-07, 02:27 PM

Helium filled SpaceShip anyone ?

http://msnbcmedia4.msn.com/j/msnbc/Components/Video/040518/050418_ascender.hlarge.jpg

Do u still want the Elevator ?

http://www.msnbc.msn.com/id/5025388/

that thing will never be able to lift anything as heavy as the space shuttle. And I really don't think that balloon is high pressure.

cato

03-24-07, 02:33 PM

uhh, yeah, helium is not lighter than a vacuum. therefore, if you want to get into orbit, you have to take off from the balloon with a rocket. carrying a rocket aboard significantly increases the weight, thus requiring a bigger balloon. however, as you increase the size of the balloon, you make it less stable, more expensive, and an overall less efficient design.

I doubt a balloon can be a practical way of getting into space.

orcot

03-24-07, 03:09 PM

I doubt a balloon can be a practical way of getting into space.

Perhaps but 42,300,000 m makes a verry verry long cable. And the cable doesn't realy need to be attached to the floor considering most models predict a anckering to a ocean floot. Perhaps a future future space elevator can be attached to a sort of carrier plane traveling around the earth each 12 hours for example.
Doubling the speed would shorten it with 75% right. But that certianly won't be for the near future

Singularity

03-25-07, 01:20 AM

These balloon shaped rockets can be used as the boosters ie. the detachable side modules of the actual rocket, i dont know why they arent aerodynamic in this picture, i guess they are meant for testing only, first phase perhaps.

http://msnbcmedia4.msn.com/j/msnbc/Components/Video/040518/050418_ascender.hlarge.jpg

After they reach the last layers or atmosphere, they should detach. The Space rocket should rise above the atmosphere and And guess what then ....

http://www.tethers.com/WebImages/MXERTether.jpg

http://www.tethers.com/OrbitToOrbit.html

orcot

03-25-07, 05:19 AM

proberly more complex and in the end better but more far off. Besides using the earths magnetic field as a power source? I believe the air presure is still going to drag you fasther then you can accelerate.

eburacum45

03-25-07, 05:21 AM

If the outward tether is the same length as the inner tether, then the outward force would be about 4% of a g.

--snip--
v= 2(84,600,000m)(3.14)/85536s = 6214m/s. Which is twice the escape speed from that altitude, which leaves you a net gain of about 3km/sec after breaking free from the Earth. This just about what you need to enter a transfer orbit to Mars.
Thank you very much. So an object dropped from the far end of the cable could get to Mars; that is what I remembered from elsewhere.

Interesting that the outward force at the far end is so low, yet the tether is in balance; I should have realised that would be the case, because the force of gravity at that distance is much smaller than it is at the Earth's surface.

eburacum45

03-25-07, 06:03 AM

The hurricane problem is a real one; Dani Eder of Boeing proposed a solution which would eliminate most of the stress put on the part of the elevator which is in atmosphere. He suggested building a tower from the ground using advanced carbon materials to rise above the bulk of the atmosphere and avoid any deformation in the tape;
see here
http://yarchive.net/space/exotic/tethers.html
I have done a conceptual design for a 10 km tower using existing
graphite/epoxy, with standard structural allowables and allowing
for a Mach 1 peak wind at 10km altitude (at jet stream altitude),
tapering down to 150 mph peak wind at ground level. The numbers
come out not too bad. Above 10 km, the lower pressure dominates
any conceivable wind speed (I assume no upper atmosphere winds
exceed Mach 1), and the 'scale height', the height over which
the cross sectional area of the structure changes by a factor
of e, increases towards the limit of the material, which is
10's of km for graphite/epoxy. If we limit the area ratio of
the tower portion to 300, then we end up with a tower on the
order of 60 km tall (this may be off by as much as a factor of
2, since I have not gone and done a detailed structural analysis)

For my model, I assumed that a tower of 15km was do-able, and here it is
http://img66.imageshack.us/img66/7071/edertower7jf.jpg

orcot

03-25-07, 06:26 AM

If that thing is Eleven km! It looks to bulky.

But how's this go right to the equator a little bid to the north of nairobi in kenia right on the equator and go to mount kenya and build it on top of that place it's a bonus 5.2 km and it's virtually on the equator. Then your building only has to be half a high.

http://upload.wikimedia.org/wikipedia/en/thumb/4/49/Kenya-relief-map-towns.jpg/503px-Kenya-relief-map-towns.jpg

Singularity

03-25-07, 07:17 AM

Singularity

03-25-07, 07:27 AM

The hurricane problem is a real one; ...

Seems like u r among the conspirators of the space elevator.

Any idea how many miles thick the elevator cable should be to take that kinda weight from 36000 miles high ?

orcot

03-25-07, 08:20 AM

PS> Do u think that a missile can be fired at it from SUDAN ?
Hmm good ID perhaps we should first level Sudan before building one. A proper fence around the area with signs like warning trespassers will be shot... well perhaps with a little cartoon for the people who can't read.

And what about Mount Everest ?
Notice the little green line saying equator?
It's at 27°59′17″N mount kenia is at 0°9′S where 0° 0′S/N is ideal. So Mount Kenia is the largest mountain less then 1° from the equator

The Chimborazo in Equador is somewhat further with 01°28′09″S if you don't mind building your elevator on a earthquake prone ?active? vulcano! But it is 6267 m So defenitly higher then Mount Kenia.

Others are higher but none that I can think of are closer or more stable then mount Kenia.

Any idea how many miles thick the elevator cable should be to take that kinda weight from 36000 miles high ?

There thinking of abouth 20 000 kg for starters so considering it's lenght it's going to be extremly light weight

eburacum45

03-25-07, 08:48 AM

Seems like u r among the conspirators of the space elevator. Not at all. I am only exploring it for the purposes of fiction; there are many other ways to get to space, and we may use any or all of those for centuries befor getting round to building an elevator.

Any idea how many miles thick the elevator cable should be to take that kinda weight from 36000 miles high ? If you mean the Eder Tower, that supports its own weight on the ground. (It obviously needs some good foundations). The elevator would weigh considerably less if the section through the atmosphere is supported on the ground.

And the elevator cable, or more properly tape, could be a few centimetres wide by the time it reaches the top of the tower. The taper factor for carbon nanotube is 29.1 according to this page;
http://science.nasa.gov/headlines/y2000/ast07sep_1.htm
so a tape which was a metre wide at the top of the Eder tower would be perhaps a little less than 29.1 meters wide when it reached the geostationary location.

eburacum45

03-25-07, 09:06 AM

The political situation is another reason why the space elevator will not be built for a long time. No-one would like thousands of kilometers of cable to fall onto their country; many countries would resist this with all their might (unless they were investing directly in it or stood to gain by access to space via the tape).

And terrorists of every stripe would see this as a perfect target; cutting the tape close to the Earth would see the tape below the cut fall to Earth, while the tape above the cut would fall upwards.

So the countryside below the elevator would need to be very secure; such severe precautions against terrorism might result in restrictions on freedom and privacy in the affected areas. Some might say that a world-wide security zone would need to be in place to prevent terrorist acts if such megastructures are to be built without becoming targets.

Do we want to live in such a secure, safe, terrorist-free society, or do some of us still value freedom above security? I am having trouble reconciling liberty with safety when imagining a possible hi-tech future society. You might have better luck.

Syzygys

03-25-07, 09:36 AM

Again, beside hurricans, there is the high altitude wind current, that is easily go by 100+ mph. How can the space elevator withstand it?

orcot

03-25-07, 09:45 AM

Any country that has a space elevator is going to gain at least enployment. I gues it would be a like the panama canal where the locals are put to work while investerors monitor everything and walk away with the mayor profit.

For the terrorist thread, you don't wreally hear of much trouble in kenia no mayor wars no mayor cival clashes. Perhaps it's not to bad over there (for africa). Perhaps a continued no weapon threaty followed with the promise that no religious inquiries are made for trade and that all man are equal will work long enough to ensure it lasts 50 or something years. If all hell brakes loose anyway you can always keep a spare that's going to be much cheaper if you're already have one in space and ancor it somewhere in the middle of the pacific with automated anti air guns a couple of subs and carriers and a promise to trow at least 5 nukes on the land of origen of the terrorist

eburacum45

03-25-07, 10:14 AM

High altitude winds do not exert very much force per square centimeter because the air is so thin up there. Perhaps the tape could be turned thin-side-on to the wind to diminish the effects further.

orcot

03-25-07, 11:03 AM

perhaps But lightning strokes are proberly going to be the mayor problem (if not corrosion). You proberly would get a lot of ice up the ribbon so each elevator should also clean the wire.

They've also made a study on how the cable would react against hard winds/storms and it could bend the cable for max a 100 km but aperently that would give verry little extra stress for the cable

Singularity

03-25-07, 11:31 AM

...

“
Any idea how many miles thick the elevator cable should be to take that kinda weight from 36000 miles high ?
”

If you mean the Eder Tower, that supports its own weight on the ground. (It obviously needs some good foundations). The elevator would weigh considerably less if the section through the atmosphere is supported on the ground.....

So u r paid by the illuminati to infiltrate human mind with your fiction the depict wrong science, hu ?

Its really amazing how u have removed the original elevator design from the entire internet, i could not find a single pic originally made by Sir Arthur C. Clarke.

Syzygys

03-25-07, 01:03 PM

High altitude winds do not exert very much force per square centimeter because the air is so thin up there. Perhaps the tape could be turned thin-side-on to the wind to diminish the effects further.

How about the elevator itself, when the serious windpower is trying to force it sideways??

orcot

03-25-07, 01:37 PM

How about the elevator itself, when the serious windpower is trying to force it sideways

:bugeye: Then it gets pushed sideways it doesn't realy has to be a straight line there are some deviation possible it goes paired with higher stress but that can be accountant for

singularity Arther C. Clarck was a writer not a illustrator besides now your guilty of american propaganda the first concept of a space elevator was tought of by the Russian Konstantin Tsiolkovsky afther seeing the Eifel tower in 1895.
But the basic concept of tether and counterweight was made by , Yuri N. Artsutanov in 1957. Arther C. Clark That introduced the name " space elevator" did it in 1978. The book was named "The Fountains of Paradise"
http://upload.wikimedia.org/wikipedia/en/thumb/9/92/Fountains_copy.jpg/200px-Fountains_copy.jpg

Singularity

03-25-07, 02:02 PM

orcot

03-25-07, 02:13 PM

then who will pay for NASA's secret weapons of mass destructions.
If your meaning the secret search for intiligent life in congress don't worry the project is doomed to fail

draqon

03-25-07, 05:12 PM

The original pic had huge helium balloons supporting the elevator, so its effective weight in the atmosphere was zero.

But if they dont take away this pic then people will realze that there is no need of the elevator itself, then who will pay for NASA's secret weapons of mass destructions.

how many times do I and all others got to tell it to you PeoPle. The helium/hydrogen balloons can suPPort weight only to 40miles above Earth...and thats in no way considered as sPace. sPace is 200km...beyond suborbital.

darksidZz

03-25-07, 10:01 PM

Ummm, this is wierd, and ummm they'll never, ever, ever, be able to build a space elevator, add to that the bizarre effects of having it visible from all over your state or country?! I'm certain there's no feasible way to construct one, and even more disturbing... what better target if a war starts than the only space-elevator in existance? You've got to be very insane to believe they'll build one of these ever, and man even I'm not that crazy.

Singularity

03-26-07, 01:59 AM

orcot

03-26-07, 03:19 AM

yeah but it somewhat failed the elevator could only reach 400 meter and the tensile strenght was only around 50 times that of steel while it should be around a 100 times as strong.

Still nanotubes have a future be it in space elevators or other things like body armor.
Darksidzz it would not be visible for a verry long distance it's dimensions will proberly be in the order of a couple of milimeters with and a couple of centimeters long and a couple of 1000 km high.

And be able to carry something like 30 ton to orbit in 8 days witch means significant time in the radio active van allen belts.

Their a lot of things against it for example how do you get a 20 000 kg in orbit and not yust any orbit but GEO not LEO even the space shuttle can't get up there, and make it unwind inside a atmosphere without damaging it.
Making that it will proberly costs a moonlander mission yust to get there.

Singularity

03-26-07, 03:35 AM

The idea is first build the

Stage 1 : Balloon supported elevator in the atmosphere

Stage 2 : LEO station having a hanging elevator just above the atmosphere, transfer the climber from Earth Elevator to the LEO Station.

Stage 3 : NEO station having another hanging elevator, transfr the Climber from LEO to NEO

Stage 4 : GEO station .....

No need of full length Elevator.

orcot

03-26-07, 05:28 AM

I think GEO orbit is essential (if you wan't to have a fixed anckoring point). The counterweight would move to fast and the cable would either snap or slow the counter weight down enough for it to reenter in the atmosphere.

besides LEO means low earth orbit (ISS /space station/ most satelites)
GEO means Geostationair earth orbit (geostationair satelites)

NEO means near earth objects and generaly refers to asteroids

Offcourse it could be done below GEO but would involve a object wide moveable platform for asteroids that are only a couple of km wide it could be a train and Venus could perhaps have a moveable floating platform but that's verry far of.

Janus58

03-26-07, 08:56 AM

The idea is first build the

Stage 1 : Balloon supported elevator in the atmosphere

Stage 2 : LEO station having a hanging elevator just above the atmosphere, transfer the climber from Earth Elevator to the LEO Station.

And how do you do the transfer, considering that the two will be moving at something in the neighborhood of 7 km/sec relative to each other?
On top of that, how do you cross the "no man's land"? (that region where the atmosphere is too thin to support a balloon, but still thick enough to cause drag problems for the LEO suspended section.)

Stage 3 : NEO station having another hanging elevator, transfr the Climber from LEO to NEO

Another velocity difference to overcome.

Stage 4 : GEO station .....

And another.[quote]

Saquist

03-26-07, 01:20 PM

Is that ramjet or scramjet?

draqon

03-26-07, 01:28 PM

X-43 scramjet will get us to space, elevators are too much nuisance.

Singularity

03-26-07, 02:44 PM

On top of that, how do you cross the "no man's land"? (that region where the atmosphere is too thin to support a balloon, but still thick enough to cause drag problems for the LEO suspended section.)

That is a problem. The climber will have to blast off from the top most end of the Elevator and do a little trip of few miles to reach outside atmosphere and hook it self to the LEO elevator.

Or the LEO Elevator will have to dip a SkyHook in the atmosphere for sometime and catch the Climber, and then pull it outside the atmosphere.

And how do you do the transfer, considering that the two will be moving at something in the neighborhood of 7 km/sec relative to each other?

http://www.mv.com/users/rogerl/aviation/jfk12.jpg

http://force.navair.navy.mil/images/Photo%20Gallery%20Pics/S-3%20carrier%20landing.jpg

http://tbn0.google.com/images?q=tbn:gl0YPWHMGqHiDM

Another velocity difference to overcome.And another.

Will have to use the Bungee Jumping Rubber band. :)

Sarkus

03-26-07, 03:10 PM

http://force.navair.navy.mil/images/Photo%20Gallery%20Pics/S-3%20carrier%20landing.jpg
LOL!

Planes landing on an aircraft deck are doing in the order of 200 km per HOUR.
The difference in orbital velocities will be in the order of 5 km per SEC

That's a mere 144,000 times faster!

orcot

03-26-07, 04:05 PM

5 km per SEC Ideal for returning pancacks

But for A LEO ID that might work is by a airplane carrier Witch basicly is a airfield large plane that flighs in the high troposfere... I don't believe in it

http://www.affordablespaceflight.com/SEf04.jpg

Singularity

03-27-07, 04:32 AM

Ideal for returning pancacks

But for A LEO ID that might work is by a airplane carrier Witch basicly is a airfield large plane that flighs in the high troposfere... I don't believe in it

http://www.affordablespaceflight.com/SEf04.jpg

Its a greate pic, seems like things can be flung out in space with it without need of any elevators,
or may be i got confused.

Singularity

03-27-07, 04:40 AM

http://home.cfl.rr.com/bbloss/mustang/index_files/image013.jpg

The above image is not what i am talking about , but a similar design can be used to create a giant AirShip that can go near space and release a JetCraft from inside its belly.

Janus58 , then we may be able to quickly match the speed of the LEO elevator orbit and so on as it climbs upper elevators.

Hope so !

orcot

03-27-07, 06:20 AM

atmospheric drag is overrated You still need a whole lot of power (meaning heavy fuelmass) to reach orbit even when your launches from a 100 km high. Besides no ramjets or scramjets is ever going to reach speeds that would actualy place it in orbit. Besides you got the same problem with the canon ones in space you still have to rely on rockets for manauvring and the orbit circular or ellips is always going to move trought he earth so you get a space hopper at best unable to complete 1 orbit

eburacum45

03-27-07, 11:58 AM

Singularity

03-27-07, 01:24 PM

The two concerpts which Singularity is referring to are the Rotovator and the Skyhook; described here
http://en.wikipedia.org/wiki/Tether_propulsion#Rotovators
http://en.wikipedia.org/wiki/Tether_propulsion#Skyhooks

We might see either or both of these concepts before we see the full-length geostationary space elevator.
But it must be borne in mind that these concepts involve matching speeds with a moving tether, sometimes with a high relative speed.

One advantage of the Rotovator concept is that it can gain momentum by lowering mass to Earth. Elsewhere we have discussed the disadvantages of mining material in space, which would be expensive to lower to the Earth's surface; with a rotovator the incoming mass provides lift for for payload coming up from the Earth.

Sorry TigerMan, dont try to distort ideas here, OK.

I wasnt talking about above things at all.

I was referring in my last post to create a Airship (Let call it AirCarrier)

The helium/hydrogen filled AirCarrier will take a JetPlane with it near the edge of atmosphere.

At the right place where its near the SkyHook ( Lets call it the SkyArrestingHook) attached to the end of the LEO elevator.

Thus when the JetPlane takes off from the AirCarrier , it has to travel very few miles near the SkyArrestingHook (which is hanging in space just above the atmosphere ).

Did u get it, Humans ?

orcot

03-27-07, 02:25 PM

So it's a skyhook :bugeye:

Note that the term airplane carrier or aircarrier like you use it is not in use. I yust riped the ID from a potential Venusian space elevator. Because a day takes over 200 days it might not be possible to build a conventional one (who nows it's even possible here). So they could make a sort of flooting city that the winds would take around the planet in 4 or so days.

So the space elevator would be attached to this carrier and planes would land on this carrier, it a way to make it shorter but it might not be economical because even if a plane travels at mach 1 it still wouldn't double the rotation speed. And building such a vast craft would be a little bid nuts.

eburacum45

03-28-07, 11:51 AM

Good idea so far; I like the floating aircraft carrier concept very much.

But you have to calculate the velocity of the lower end of the SkyArresting Hook, so that you know how fast your Balloon-launched transfer craft needs to go in order to match speeds with the Hook.

Here's a clue; the Sky Arresting Hook will be in Low Earth Orbit, so will be moving at orbital speed for its centre of gravity.

Unless you rotate it in the opposite direction to its orbital path, as described in the Rotovator concept, that speed probably will be quite a bit more than ten thousand kilometers per hour, depending on the length of the SkyArresting hook.

That is why I pointed you in the direction of these pre-existing concepts, Singularity, so that you can see that other people have already done the maths for these concepts and that should help you fine-tune your own idea.

Singularity

03-28-07, 12:14 PM

so u mean even though the Rotovator throws the Climber in the upper orbit, it doesnt fall towards earth each time ?

EndLightEnd

03-28-07, 12:32 PM

Ok but we still need carbon nano-tubes for a space elevator, and this process is still being researched and tested.

orcot

03-28-07, 03:43 PM

researched and tested and applied not? I believe their in the most recents flatscreens and might replace plasma screens... might

link (http://www.nsti.org/Nanotech2007/workshops/carbon_nano_tubes.html)

eburacum45

03-29-07, 11:26 AM

so u mean even though the Rotovator throws the Climber in the upper orbit, it doesn't fall towards earth each time ?
Well spotted! Yes, it does, so it needs to be lifted back into a higher orbit before it can be used again. This can be done in one of two ways- the tether can be lifted by running an electric charge through it, which causes the Earth's magnetic field to accelerate it; this leads to the rotovator achieving a higher orbit (A process known as tether propulsion). The electric charge can come from solar panels.
Or;
the rotovator can be lifted by lowering material from space into orbit. Thus allowing commodities mined in space (if any) to be lowered to Earth very cheaply.

Singularity

03-29-07, 01:36 PM

... the tether can be lifted by running an electric charge through it, which causes the Earth's magnetic field to accelerate it; this leads to the rotovator achieving a higher orbit (A process known as tether propulsion). The electric charge can come from solar panels.
Or;
the rotovator can be lifted by lowering material from space into orbit. Thus allowing commodities mined in space (if any) to be lowered to Earth very cheaply.

Ok , all this sounds greate. And now a very funny question that i resisted for years or didnt find the right people to ask.

When we see videos of Astronauts in freefall/space they can move any heavy weight with greate ease, ie. pushing throwing or pulling. And they can do this in any direction.

So the question is, If i am doing space walking being in orbit around earth and i have 1KG weight in my hand. And i throw it up with quite a force (humanly possible).

How far will it rise above the earth ?

Since its weight is zero for the Astronaut it seems it will go on forever up away from her.

orcot

03-29-07, 01:47 PM

So the question is, If i am doing space walking being in orbit around earth and i have 1KG weight in my hand. And i throw it up with quite a force (humanly possible).

Asuming their is no air resistance it's orbit would become more ellips and would proberly pass the same point afther each orbit. Don't forget the weight might chance but the mass doesn't

Singularity

03-29-07, 01:58 PM

Asuming their is no air resistance it's orbit would become more ellips and would proberly pass the same point afther each orbit. Don't forget the weight might chance but the mass doesn't

but the weight should always go away from me in a straight line, and i have thrown it in the opposite direction to earth.

Janus58

03-29-07, 03:49 PM

but the weight should always go away from me in a straight line, and i have thrown it in the opposite direction to earth.

It won't, as it is under the influence of Earth's gravity.
From the Astronaut's viewpoint, It will start moving directly away from the Earth and then start to fall further and further behind the Astronaut in her orbit. At some point it will reach a maximum distance from the Earth and start moving back towards the Earth. At that time, the rate at which it is falling behind the Astronaut will begin to decrease. It will eventually cross the astronaut's orbit and will start getting closer to the Earth than the astronaut. It will now start to gain on the astronaut. It will reach a low point and then start climbing back up again. eventually crossing the astronaut's orbit at the same point at which it was thrown. However, it will cross behind the Astronaut, as its orbital period will be slightly longer.

From the Earth's view, it will enter a new orbit with a higher perigee and lower apogee than the astronaut's.

Singularity

03-29-07, 05:18 PM

Thats really hard to digest, but thanks anyways, Janus58.

D H

03-29-07, 05:21 PM

but the weight should always go away from me in a straight line, and i have thrown it in the opposite direction to earth.

The object has mass. The Earth pulls on this mass. It won't go away in a straight line.

However, it will cross behind the Astronaut, as its orbital period will be slightly longer.

This is correct. However, that "slightly longer" is very slight indeed. If the astronaut throws the 1kg mass "straight up", the change in orbital energy is very, very small. Much more interesting things happen if the astronaut throws the object forwards, backwards, or sideways relative to the astronauts motion around the Earth. In all cases, the object starts moving in the direction it was thrown but then some very counterintuitive things happen. Assuming the astronaut is in a circular orbit, here is what will happen:
Forwards. The object will start moving up shortly after being thrown. As it rises, it will slow down with respect to the astronaut. Eventually, the astronaut will overtake the object. Half an orbit later, the object will reach its maximum height above the astronaut. It will start to descend, just touching the astronaut's orbit after another half rev (where it will begin to rise again). At this point (one rev after being thrown), the ball will be well behind the astronaut. It will move progressively further from the astronaut as time passes.
Backwards. The reverse happens when the ball is thrown backwards. It reverses direction, eventually passing the astronaut.
Sideways. Denote vbar as the unit vector along the astronaut's velocity vector direction (This unit vector rotates with the astronaut's orbit). The object will start rising slightly and turning toward the -vbar direction. The object will be above and behind the astronaut 1/2 rev later, where it will start falling and turning toward the plus vbar. The object will come very close but very slightly behind to the astronaut after another 1/2 rev, at which point it will repeat this behavior. The object will move very slowly away from the astronaut over time. By adding just a little backwards velocity to the initial throw, the astronaut can make the mass come right back to him.

orcot

03-29-07, 05:41 PM

All this info has long been rechearged for NASA's secret space programe to built a space golf course.

nexusfruit

04-01-07, 08:58 PM

Along with the 'MARS MISSIONS', once again...NASA is used to distract everybody from the military politics down here on earth. Same thing happened during the JFK administration. You would be quite foolish to assume that any government money spent on a space program is used "for mans further exploration of the cosmos". It's called Intelligence. And the guys in charge know how to get what they want. NO, there will never be a space elevator. There's nothing in space for man. We are just in denial that we were meant to stay here, beneath the bands of deadly radiation. And there will never be flying cars or any of that whooy.

Singularity

04-01-07, 10:41 PM

I hope u r aware that NASA is not the only space agency in the world.

draqon

04-01-07, 11:16 PM

I hope u r aware that NASA is not the only space agency in the world.

lol :p :rolleyes:

orcot

04-02-07, 03:03 PM

dragon do not underestimate the chinese space program nor the under funding from NASA. I forsee that Nasa is going to either have to stop it's moon and mars mission in the next couple of 5 years or is going to have to do some serious investments if it would like to keep it's weather satelites and the other verry unsexy parts of the space backbone. While the Chinese are proberly going to buy half of the russians space port for the technology.

Hopefully the verry ... Iraqi situation. Are going to use space to put their heads in the sand for a while. Spending that half a trillion dollar on space, welfare, defecit, etc would proberly turn up some nicer newspaper articles.

But somehow I think that if there 's ever going to be a investment in a space elevator then it's going to be a mutual project because everybody would wan't to have some control over it (assuming it can be build).

nexusfruit

04-02-07, 08:01 PM

Yeah and McDonalds isn't the only fastfood joint in the world either. Besides, wouldn't a piece of tape just wrap around the earth instead of staying static? The moon's gravity might have some affect as well. I think that it would make more sense to have it tethered in the opposite direction, so that the anchor in orbit becomes a place to dangle the bobber over the earth instead of attached to it.

Singularity

04-03-07, 04:01 AM

... if there 's ever going to be a investment in a space elevator then it's going to be a mutual project because everybody would wan't to have some control over it (assuming it can be build).

It would be better to put the elevator in a world neutral zone and be kept open for anyone who pays for it.

This will thwart any attempt to attack it.

Mostly USA will try to control it, if they do then i hope it falls on white house in case of an attack.

orcot

04-03-07, 12:49 PM

It's going to be owned by whoever pays for it not who invented the technology, china India and the middle east are yust as likly to own it as the US... Yeah right... but the US is going to have to pull strings for it and aftherwards others can always make a second cheaper version

Singularity

04-27-07, 07:49 AM

http://home.cfl.rr.com/bbloss/mustang/index_files/image013.jpg

The above image is not what i am talking about , but a similar design can be used to create a giant AirShip that can go near space and release a JetCraft from inside its belly.

...

Hope so !

Whats not possible,

http://p.airliners.net/photos/middle/5/1/7/1100715.jpg

http://www.alaska.faa.gov/fai/images/Aircraft/SGUP-c.jpg

orcot

04-27-07, 08:44 AM

:bugeye:

Singularity

04-27-07, 09:20 AM

:bugeye:

http://www.flygplan.info/images/Aero_Spacelines_Super_Guppy2.jpg

i mean its possible to built such AirShips but they wont.

And place a SpaceCraft in its belly like this,
http://www.boeing.com/news/releases/2007/photorelease/q1/070112a_lg.jpg

Nikelodeon

04-27-07, 09:22 AM

http://www.generationmp3.com/popnext/images/juin2005/beluga-airbus.jpg

Positron

04-27-07, 09:58 AM

very....interesting....leave it to aribus to coem out with new radical tech.

Singularity

04-27-07, 11:28 AM

very....interesting....leave it to aribus to coem out with new radical tech.

Why leave it to them ? Lets help them.

http://hotimg6.fotki.com/a/124_7/88_106/JumboAirShip.jpg

I always wonder why they dont do something like this.

Adding more, they can add more wings in different plains, ie, three on top, three in the center and three as shown in this pic; and after that they and stretch it so that it will be like three these planes sticked side by sides. So total of 18 wings. Hence 9 times the size of the original pic, but same height.

Nikelodeon

04-27-07, 11:31 AM

The air turbulence from the front wing would spoil the last two wings.

draqon

04-27-07, 11:32 AM

this thread is about space elevators.

http://www.liftport.com/
Lets discuss about how space elevators can be powered by.

http://www.liftport.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=378&g2_serialNumber=2

Singularity

04-27-07, 11:41 AM

The air turbulence from the front wing would spoil the last two wings.

I know;
we should adjust their position such that the low pressure created from the first wing is on top of the next and so on.

orcot

04-27-07, 04:19 PM

Singu can't you make a other thread about this, this is abouth space elevators and I hate to see it spoiled on other topics, there are some nice designs like the solar plane that can (cheaply) replace satelites et etc. So why not make it a new threat entirely

http://en.wikipedia.org/wiki/Space_elevator
According to the site the tether should have a tensile strengt/density ratio of 65-120GPa and space and the neccesairy technology chould be developed as soon as 2008. As of now the strongest nanotubes only reach 52theoretical with a min breaking strengt at 30GPa(diamond is little more then 20GPa.

Kaz

04-27-07, 04:29 PM

Won't happen. The elevator couldn't travel fast enough up to escape our atmosphere, etc. to get into space.

draqon

04-27-07, 04:44 PM

Won't happen. The elevator couldn't travel fast enough up to escape our atmosphere, etc. to get into space.

it doesnt have to. otherwise all elevators would have to travel that fast :rolleyes:

orcot

04-27-07, 05:11 PM

Won't happen. The elevator couldn't travel fast enough up to escape our atmosphere, etc. to get into space.

what's fast?
The cable will be 35800 km. A craft that travels at 200 km/h would take 179 hours or around 7,5days. I agree that no human can witstand elevator music for so long but if protectics are installed against space radiation and their are simple resources like beds kitchens recreation etc it's duable.

Singularity

04-27-07, 09:08 PM

Singularity

04-27-07, 09:29 PM

We must marry this technology http://www.defenseindustrydaily.com/images/AIR_High_Altitude_Airship_lg.jpg

with

http://hotimg6.fotki.com/a/124_7/88_106/JumboAirShip.jpg

ie. There will be an even bigger underBelly to this beauty filled with hydrogen.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

BTW, http://www.defenseindustrydaily.com/2005/07/usaf-looking-at-nearspace-blimps/index.php

I hope they are successful, to pave way for air to space jumps in the future.

draqon

04-27-07, 09:35 PM

SINGULARITY THIS THREAD IS ABOUT Space Elevators!!!!!!!!!!!!

orcot

04-28-07, 01:55 AM

Mr. Orcot,

after being already proved in my previous posts why SpaceElevator is not a good idea , I have posted that pic here.

... no you've posted a alternative, a other alternative (possibly cheaper) way to get in space however it's as different from a space elevator as chemical rockets sutch if you wan't do discus it why don't make a new threat?

Singularity

04-28-07, 08:20 AM

... no you've posted a alternative, a other alternative (possibly cheaper) way to get in space however it's as different from a space elevator as chemical rockets sutch if you wan't do discus it why don't make a new threat?

First , i dont believe in threats, instead i take direct actions :D .

Second, please read this thread again, SpaceElevators have been debunked; Replaced with AirShip that take JetCraft to near space and then the JetCraft takes off into space and attaches to the tethers.

Nikelodeon

04-28-07, 08:59 AM

SINGULARITY THIS THREAD IS ABOUT Space Elevators!!!!!!!!!!!!
Exactly.

Singularity

04-28-07, 09:15 AM

Exactly.

What ! :confused: http://sciforums.com/avatars/avatar23456_96.gif

draqon

04-28-07, 10:10 AM

What ! :confused: http://sciforums.com/avatars/avatar23456_96.gif

stoP discussing some balloons/Planes in a sPace ELEVATOR THREAD.

Singularity

04-28-07, 01:15 PM

stoP discussing some balloons/Planes in a sPace ELEVATOR THREAD.

Dont make a fool out of yourself

First read the thread and try to understand why SpaceEvelvator was Debunked.

It will be clear why these post are here, they are infact about the space elevator.

Nikelodeon

04-28-07, 01:54 PM

stoP discussing some balloons/Planes in a sPace ELEVATOR THREAD.

Exactly.

CANGAS

05-01-07, 03:05 AM

Space elevator has so many enormous practical engineering problems on ( over? ) a planet like Earth that it will not happen as a utilitarian device. A technology abvanced enough to build one would be so abvanced that there would be many other ways, all much more efficient, to get into orbit so that an orbit elevator would only be an amusement, like a Ferris wheel or a merry go round.

Singularity

05-01-07, 03:41 AM

“
Originally Posted by draqon
stoP discussing some balloons/Planes in a sPace ELEVATOR THREAD.
”

Exactly.

Eat this,

http://liftoff.msfc.nasa.gov/rsa/gifs/buran_an225.jpg

Actual photo, clearly NASA know people are stupid.

Nikelodeon

05-01-07, 03:45 AM

Your point?

Singularity

05-01-07, 04:11 AM

Your point?

http://sciforums.com/showpost.php?p=1370555&postcount=101

hence no need of any elevators,

http://liftoff.msfc.nasa.gov/rsa/gifs/buran_an225.jpg

CANGAS

05-01-07, 04:40 AM

Singularity

05-01-07, 04:53 AM

Blimp can carry rocket to 100,000 feet or higher; advantage of doing so is to get above virtually all atmospheric drag before starting engine. But, still have to use most of fuel to fight gravity before attaining orbital velocity.

Advantage of mythological orbit elevator is to supposedly get orbital velocity simply by walking up really long spiral stair to orbit altitude ( and velocity ).

Guess what. You don't get orbit velocity on an orbit elevator until you get way up there to geostationary orbit altitude. That's many, many, many thousands of miles up there.

You don't go many, many, many thousands of miles straight up for free. You have to pay many, many, many Joules for the fun.

I don't like the idea of riding the Russian jet to 50,000 feet. I like the idea of riding a blimp to 150,000 feet and then starting the motor.

You like chocolate. I like butterscotch.

Hey CANGAS, good u came back to SciForums. There is a severe shortage of intelligent people here.

If u read this long thread, u will notice that we came to conclusion that rotating tether is better than climbing the elevator kept outside earths atmosphere.

Hence i was thinking of a Hydrogen elevated giant Airship that takes a JetCraft above or near edge of atmosphere. And then that JetCraft makes a short trip to the nearest solar powered rotating tether , so no more space traveling expenses :)

CANGAS

05-01-07, 06:06 AM

CANGAS ashameadly confesses to not reading long thread prior to posting.

Rotating tether must be anchored on Earth surface and must have enough mass far enough away from surface to generate enough centrifugal force to overcome gravity. Tough job and big practical engineering problems.

If tether hangs down from satellite in geostationary orbit, then plenty of big problems. Forget it. Centrifugal force throws it higher. It doesn't hang down.

If tether is anchored on surface and attached to satellite in geostationary orbit, enormous practical engineering problems in getting it erected.

Goal of venture is not just to be in orbit. Goal is to then accelerate to escape velocity and go on to Moon or Mars or other delightful destinations for vacation or whatever. So, flight strategy is to leave surface and get to escape velocity using least amount of fuel. Only real variable is amount of fuel wasted by atmospheric drag. Whether climbing up really high spiral stair or roaring up on rocket, same amount of Joules needed to get up there if disregard air drag.

So why not ride a blimp to 150,000 and then light it up?

OK, you like big Russian jet and I like blimp. Like I say, you like chocolate and I like butterscotch.

orcot

05-01-07, 06:07 AM

http://liftoff.msfc.nasa.gov/rsa/gifs/buran_an225.jpg
This is not a space shuttle it's a Russian buran. That is moved from it's storage point to the launching pad.

Hence i was thinking of a Hydrogen elevated giant Airship that takes a JetCraft above or near edge of atmosphere. And then that JetCraft makes a short trip to the nearest solar powered rotating tether , so no more space traveling expenses
Basicly your ID isn't verry bad but the quistion remains on how large the rocket chould be a basic ariane 5 weights as much as 700 ton. The weights would be greatly reduced but your still proberly going to have to carry 1/2 of the weight, so your still with a +300 ton primairy vehicle. Then depending on how high you would like to launch their is the obvious size of the secondairy vehicle do not forget that a balloon is filled with hydrogen (= explosive).
Anyway the most economic is that the rocket no longer needs to start of with a 100% verticale clime. But it's still going to need to gather most of it's speed. Aftherall getting high is not the problem getting up to speed to stay in orbit is.

Singularity

05-01-07, 08:29 AM

http://liftoff.msfc.nasa.gov/rsa/gifs/buran_an225.jpg
This is not a space shuttle it's a Russian buran. That is moved from it's storage point to the launching pad. Greate.

... the quistion remains on how large the rocket chould be a basic ariane 5 weights as much as 700 ton.

How much weight do u want to put up there ?

http://hotimg6.fotki.com/a/124_7/88_106/JumboAirShip.jpg

We will have to create AirShips much much bigger than that if humans want to conquer space.

The weights would be greatly reduced but your still proberly going to have to carry 1/2 of the weight, so your still with a +300 ton primairy vehicle.

Why do u think so ?

Then depending on how high you would like to launch their is the obvious size of the secondairy vehicle do not forget that a balloon is filled with hydrogen (= explosive). What is secondary ? Its just a powerful Plane.

It can be designed to be explosive proof (along with robust testing).

Anyway the most economic is that the rocket no longer needs to start of with a 100% verticale clime. But it's still going to need to gather most of it's speed. Aftherall getting high is not the problem getting up to speed to stay in orbit is.

The speed depends on the speed of the rotating tether rather than escape velocities. I dont know what will that be, if the lower end of tether is going opposite of the orbital direction.

EmptyForceOfChi

05-01-07, 09:43 AM

why dont they create huge orbital space stations like the one we have already but massive in size, also capable of building and launching spacecraft from the actual station itself so you dont have to fight any type of gravitational pull on blastoff,

the station could sustain life and have its own eco system, huge solar panels could be build in orbit to soak up the suns rays for power. plants and trees could be grown in mass number inside, exo skeleton resistance suits could be created for people to wear.

i think having a permanent outpost in space would be the way forward if we want to conqour it, stop comming back down to earth all of the time,

peace,

EmptyForceOfChi

05-01-07, 09:49 AM

this is crappy and outdated.
http://www.resonancepub.com/images/s97_15166.jpg

thats more like it,
http://www.worth1000.com/web/media/22287/star%20wars%20death%20star.jpg

or even this,
http://www.smallartworks.ca/Gallery/DS9/Ds9_1.JPG

Singularity

05-01-07, 10:53 AM

EmptyForceOfChi,

we are talking exactly that and specially how to send all that up at dirt cheap costs.

EmptyForceOfChi

05-01-07, 11:38 AM

ahh good good, i like this idea, well the blimp idea seems cheaper to me than the huge plane idea,

what about a hovering station that hovers at extream altitudes, like a huge blimp station wich can act as a platform and is flat on the surface, with help of underside thrusters and overhead propellers.

it could be a permanent hover station atleast 150,000 ft up,

peace,

EmptyForceOfChi

05-01-07, 11:45 AM

kinda like this
http://www.geocities.com/tommysdiablo7/airship1.jpg

with flying electric generators.
http://www.skywindpower.com/ww/images/Ben's%2015%20degree%20tilted%20roto%20FEG.jpg

this is a cmmercial space habitat design
http://www.hobbyspace.com/AAdmin/Images/Tourism/spaceIsland_27a.jpg

orcot

05-01-07, 11:46 AM

why dont they create huge orbital space stations like the one we have already but massive in size

Budget problems:rolleyes: Their is a increase off potential interesting space activities but the funds stay the same (let face it funds are actually dropping), then offcourse their is the fact that NASA sees everything like a race so they do not exept help from others... I can see why they don't want to work with the certain countries but to refuse help from the Russians :bugeye: their proberly better up in space then the americans.

What is secondary ? Its just a powerful Plane.
A powerfull plane??? I've got a better ID why don't we launch a stargate in orbit

It can be designed to be explosive proof
Do you believe it's possible to make something explosion proof that's most proberly is going to exist of large quantaties of hydrogen and oxygen

The speed depends on the speed of the rotating tether rather than escape velocities. I dont know what will that be, if the lower end of tether is going opposite of the orbital direction.
No it's better with the earths rotation that way you get a extra 465.11 m/s due to the rotation of the earth itself

EmptyForceOfChi

05-01-07, 11:53 AM

just a thought, what is the tallest possible building/structure that mankind could possibly make?.

would it be possible for the UN to gather all participants together to create a huge structure, possibly situated atop of a mountain or very high ground, so that it would get us closer?

would that atleast help or no not really?

peace.

EmptyForceOfChi

05-01-07, 11:56 AM

what is the biggest downfall and flaw in this space elevator?.
http://www.jonathanminard.com/EarthSpace/spaceelevator.jpg

what if we drilled through the core of mount everest, with the elevator going right the way through the surrounding mountain would give it plenty of support and stability, and if the elevator was slightly coned like an isosolies triangle it would also give added structure support,

maybe?

peace,.

orcot

05-01-07, 12:04 PM

the tallest building that their planning to build would be around 800 meters high (http://en.wikipedia.org/wiki/Skyscrapers#History_of_tallest_skyscrapers)
The best mountain around the equator would be mount kenia with 5,199 m (http://en.wikipedia.org/wiki/Mount_Kenia) at 0°9′S, 37°18′E

so you get abouth 6 km high at this altitude their is less then 50% air pressure to reduce your craft and the rotation velocity is also somewhat higher

EmptyForceOfChi

05-01-07, 12:09 PM

i think that might be a good route to try then, it doesent sound too expensive.

peace.

Oli

05-01-07, 02:08 PM

it could be a permanent hover station atleast 150,000 ft up,
Considering that in the hover you lose approximately 10 lbs of thrust per 30 of altitude due to reduction in air pressure, then you're 5000 lb down on each engine already. And don't forget that very few vehicles (and no air breathing aircraft) have reached, let alone sustained 150,000 ft. That's just under twice what an SR-71 gets to...

EmptyForceOfChi

05-01-07, 02:15 PM

what about something along the lines of a stratellite?

peace,

Oli

05-01-07, 02:22 PM

Then it will be in some sort of low orbit and you'll still have to fly up/ down to it at some point...
How do loft enough materials to build it? You might as well go for a full-blown space or moon station.

EmptyForceOfChi

05-01-07, 02:35 PM

i was thinking more along the lines of a low altitude station like a stratelite, then a much larger orbital space station that could be linked together, so it would be easyer to transfer things from 1 to the other, and you could use an elevator from 1 to the other so there would be a better linkway from in atmosphear to outer orbit,

if you kinda follow what i am saying? a low altitute stratelite hover station within the earths atmosphear that is connected to an outer orbiting space station that are both manned and linked together, so transporting materials from earth 2 space could in the long run be cheaper,

no? space travel is not my specialty but i will give it a go,

peace.

EmptyForceOfChi

05-01-07, 02:38 PM

this is the best i could find to represent what i am saying,
http://www.whatsnextnetwork.com/technology/media/artemis.jpg

peace.

EmptyForceOfChi

05-01-07, 02:41 PM

imagine that is anouther station and that beam is a cable elevator, connecting one station to the other, the low station could be manned fully and breaks could be taken from the space station, so rest would be easy and would not require to land on earth.
http://www.whatsnextnetwork.com/technology/media/artemis.jpg

Oli

05-01-07, 02:42 PM

if you kinda follow what i am saying? a low altitute stratelite hover station within the earths atmosphear that is connected to an outer orbiting space station that are both manned and linked together, so transporting materials from earth 2 space could in the long run be cheaper,
If one end is in the atmosphere then how will you compensate for the drag it causes on the one that's not?

EmptyForceOfChi

05-01-07, 02:57 PM

i figured that they would both orbit and hold together, and one would drag the other around :)

forgive my simplistic thought, wouldent that work?

peace.

orcot

05-01-07, 02:58 PM

If one end is in the atmosphere then how will you compensate for the drag it causes on the one that's not?

The counterweight could be a little to high so that there is a constant upwards pressure counterring the drag (But I'm guessing that the the tether chould be weighted down from the bodem to to keep the line tight)

EmptyForceOfChi

05-01-07, 03:02 PM

yeah what orcot said. that was my idea he stole it :)

peace.

Oli

05-01-07, 03:02 PM

i figured that they would both orbit and hold together, and one would drag the other around
If one is moving slower than the other then it will slow down the faster one - and eventually pull it out of orbit. The higher one would lose energy making up for the atmospheric drag on the lower.
For orbits the closer you are to Earth the faster you should move to remain in orbit.

Singularity

05-01-07, 03:15 PM

http://science.nasa.gov/headlines/images/tethers/CarrollTTF.GIF

Best link found on the topic,
http://science.nasa.gov/headlines/y2000/ast09jun_1.htm

EmptyForceOfChi

05-01-07, 03:55 PM

that is a good link,

oli, so if a little motion was in play to keep up there would be no drag right?

peace.

Oli

05-01-07, 04:23 PM

If you're in atmosphere there will be drag - the trick is offsetting the drag. The picture Singularity posted offsets the drag by adding velocity during the pickup.

orcot

05-01-07, 04:29 PM

and by not being constantly in the atmosphere constantly I wonder with what speed it get's whiped through the atmosphere

EmptyForceOfChi

05-01-07, 04:31 PM

ok i think i understand how that works .

peace.

CANGAS

05-07-07, 02:25 AM

Bad news: No free lunch.

Going straight up from Earth surface to geostationary orbit requires many, many Joules. Because gravity is always pulling down.

Earth surface at Equator moving very roughly speaking 1,000 MPH. So any object on surface has angular momentum based on that speed. Object moving many, many, many thousand miles up to geostationary satelite has only tiny angular momentum. Geostationary satelite has momentum based on many, many, many thousand MPH more speed. For about 400 years momentum, including angular momentum, has been policed to be strictly conserved. So, object climbing up high spiral stair constantly must use Joules to keep up sideways speed. When object reaches high geostationary satelite, HONEST book keeper must confess that Joules used to keep up sideways speed plus Joules used to go straight up against gravity equals total amount of Joules used by clumsy old fashioned rockets.

Don't shoot me, I'm just the messenger. OK?

Singularity

05-07-07, 02:54 AM

CANGAS,

Do u think that the speed of objects in near earth orbits is more that of geostationary orbits ?

orcot

05-07-07, 06:48 AM

I'm not CANGAS but sure (http://en.wikipedia.org/wiki/Specific_orbital_energy#Examples)

Singularity

05-07-07, 07:16 AM

I'm not CANGAS but sure (http://en.wikipedia.org/wiki/Specific_orbital_energy#Examples)

If u r so sure then what do u think about his comments ?

DO u think he should be shot at for it.

Singularity

05-07-07, 07:23 AM

Bad news: No free lunch.

Going straight up from Earth surface to geostationary orbit requires many, many Joules. Because gravity is always pulling down....

Don't shoot me, I'm just the messenger. OK?

Message from whom, illuminati ?

Pete

05-07-07, 08:15 AM

When object reaches high geostationary satelite, HONEST book keeper must confess that Joules used to keep up sideways speed plus Joules used to go straight up against gravity equals total amount of Joules used by clumsy old fashioned rockets.

Clumsy, old fashioned rockets have to carry their fuel and reaction mass with them. This means lifting a lot more than just the payload to begin with.

For example, to send 6 tonnes of satellite to geostationary orbit on an Ariane 5G rocket meant lifting 740 tonnes of extra stuff (including 630 tonnes of fuel and oxidizer) off the launchpad.

Climbing a cable has two advantages over rockets - firstly, no reaction mass is required. Secondly, the energy source doesn't need to be carried on board - energy can be supplied electrically through the cable.

This means that the same 6 tonne payload could be lifted to the same orbit at a cost of perhaps 30 tonnes of gasoline (assuming 20% efficiency).

Janus58

05-07-07, 12:54 PM

Clumsy, old fashioned rockets have to carry their fuel and reaction mass with them. This means lifting a lot more than just the payload to begin with.

For example, to send 6 tonnes of satellite to geostationary orbit on an Ariane 5G rocket meant lifting 740 tonnes of extra stuff (including 630 tonnes of fuel and oxidizer) off the launchpad.

Climbing a cable has two advantages over rockets - firstly, no reaction mass is required. Secondly, the energy source doesn't need to be carried on board - energy can be supplied electrically through the cable.

Not only that, but with proper designing, you should be able to harness at least some of the potential energy of cars coming back down the cable and feed it back into the system.

P.S.
Another advantage is that the Elevator need not supply the energy needed to conserve angular momentum; that is borrowed from the Earth's own rotation (And given back to the Earth when a car comes down)

CANGAS

05-15-07, 02:00 AM

CANGAS,

Do u think that the speed of objects in near earth orbits is more that of geostationary orbits ?

Yes.

Why do u have to ask this question?

CANGAS

05-15-07, 02:00 AM

[QUOTE=orcot;1381301]I'm not CANGAS but sure (http://en.wikipedia.org/wiki/Specific_orbital_energy#Examples)

?

CANGAS

05-15-07, 02:03 AM

Message from whom, illuminati ?

From laws of physics. U know about laws of physics or only about crackpot things?

CANGAS

05-15-07, 02:04 AM

Clumsy, old fashioned rockets have to carry their fuel and reaction mass with them. This means lifting a lot more than just the payload to begin with.

For example, to send 6 tonnes of satellite to geostationary orbit on an Ariane 5G rocket meant lifting 740 tonnes of extra stuff (including 630 tonnes of fuel and oxidizer) off the launchpad.

Climbing a cable has two advantages over rockets - firstly, no reaction mass is required. Secondly, the energy source doesn't need to be carried on board - energy can be supplied electrically through the cable.

This means that the same 6 tonne payload could be lifted to the same orbit at a cost of perhaps 30 tonnes of gasoline (assuming 20% efficiency).

As usual, Pete's post fails to address the point.

CANGAS

05-15-07, 02:20 AM

Not only that, but with proper designing, you should be able to harness at least some of the potential energy of cars coming back down the cable and feed it back into the system.

P.S.
Another advantage is that the Elevator need not supply the energy needed to conserve angular momentum; that is borrowed from the Earth's own rotation (And given back to the Earth when a car comes down)

If an orbit elevator has what is called in structural engineering terms a moment connection with the rotating surface of the Earth then J's post could be true in principle.

What J does not understand is that a tether hanging down from a geostationary satelite cannot possibly have a moment connection with the angular momentum of the surface of the planet.

J has too much to learn before being able to make a cogent post on this topic.

A rigid structure rising up from the planet surface can transfer the planet's angular momentum to the stair-climbing orbital wannabee.

A freely hanging tether suspended from a satelite CANNOT transfer ANY of the planet's angular momentum to the pilgrim. Except in the negative sense: the lesser angular momentum of the climbing pilgrim will retard the satelati, dragging it down and decaying its orbit.

Sorry, orbit wannabee, climbing up a hanging tether is NOT a free lunch, no matter what it looked like in an hallucination.

Pete

05-15-07, 03:14 AM

As usual, Pete's post fails to address the point.
It directly addressed the point quoted, which was about energy.

Come on, honest bookkeeper, show us how to tidy the books :rolleyes:

Janus58

05-15-07, 06:50 PM

If an orbit elevator has what is called in structural engineering terms a moment connection with the rotating surface of the Earth then J's post could be true in principle.

What J does not understand is that a tether hanging down from a geostationary satelite cannot possibly have a moment connection with the angular momentum of the surface of the planet.

J has too much to learn before being able to make a cogent post on this topic.

A rigid structure rising up from the planet surface can transfer the planet's angular momentum to the stair-climbing orbital wannabee.

A freely hanging tether suspended from a satelite CANNOT transfer ANY of the planet's angular momentum to the pilgrim. Except in the negative sense: the lesser angular momentum of the climbing pilgrim will retard the satelati, dragging it down and decaying its orbit.

Sorry, orbit wannabee, climbing up a hanging tether is NOT a free lunch, no matter what it looked like in an hallucination.

A space elevator, in its final form, does not consist of a cable hanging from a satellite at geostat. To build a space elevator, you start at geostat orbit and build down. At the same time, you build up from geostat. This is to maintain the CoG of the entire structure at geostat. (otherwise it will drift out of position) This can be as simple as lowering a cable from geostat, while at the same time as letting out a cable upward. (tidal forces will ensure that the cable will extend outward.

Once the cable reaches the Earth, you anchor it. Now you start shifting mass from geostat orbit outward along the cable. When it reaches the other end it becomes the other anchor point. The end of the cable is traveling much faster than orbital speed for that altitude so the mass trys the fly away form the Earth. The cable keeps it from doing so and is under tension.

The mass is made large enough that even with a maximum load car climbing up the cable, the CoG of the entire structure remains above geostat orbit altitude. as long as the Cog of the Whole structure remains above this altitude, it behaves, not like an satellite in orbit, but like a rock being swung around in a circle on the end of a string.

As to angular momentum transfer goes:

As the car climbs the cable, it will want to lag behind the Earth's spin. but as it does so, the cable will no longer be perfectly vertical. The Earth will now pull forward on the slanted cable transfering some of its angular momentum to the Car. The cable will only slant while the car is climbing. Once the car reaches its destination, the system will go back to vertical with the car enjoiyng the extra angular momentum it recieved from the Earth.

So yes, a tether style space elevator still transfers angular momentum from the Earth to the rising car.

And a rising car will not pull down a properly counter-weighted tether style space elevator.

2inquisitive

05-16-07, 01:05 AM

You guys are getting confused about what each is addressing in this thread. It started out discussing a space elevator anchored to the Earth, but near the end, the thread and CANGUS had begun discussing a tether connecting two orbiting satellites and not connected to the Earth. Pete and Janus58 started speaking of Earth momentum transfer in conjunction with an anchored space elevator again, but CANGUS was still speaking of a tether system with no anchor point on Earth's surface, thus no transfer of Earth's momentum.

There are huge engineering problems that may be impossible, or near impossible, to overcome to make either system practical even if money were not a consideration.

Pete

05-16-07, 01:25 AM

Hi 2inq,
In the post I responded to, CANGAS was talking about a climbing to a geostationary satellite from Earth's surface.

I agree with you regarding the engineering problems.

CANGAS

05-16-07, 01:57 AM

A space elevator, in its final form, does not consist of a cable hanging from a satellite at geostat. To build a space elevator, you start at geostat orbit and build down. At the same time, you build up from geostat. This is to maintain the CoG of the entire structure at geostat. (otherwise it will drift out of position) This can be as simple as lowering a cable from geostat, while at the same time as letting out a cable upward. (tidal forces will ensure that the cable will extend outward.

Once the cable reaches the Earth, you anchor it. Now you start shifting mass from geostat orbit outward along the cable. When it reaches the other end it becomes the other anchor point. The end of the cable is traveling much faster than orbital speed for that altitude so the mass trys the fly away form the Earth. The cable keeps it from doing so and is under tension.

The mass is made large enough that even with a maximum load car climbing up the cable, the CoG of the entire structure remains above geostat orbit altitude. as long as the Cog of the Whole structure remains above this altitude, it behaves, not like an satellite in orbit, but like a rock being swung around in a circle on the end of a string.

As to angular momentum transfer goes:

As the car climbs the cable, it will want to lag behind the Earth's spin. but as it does so, the cable will no longer be perfectly vertical. The Earth will now pull forward on the slanted cable transfering some of its angular momentum to the Car. The cable will only slant while the car is climbing. Once the car reaches its destination, the system will go back to vertical with the car enjoiyng the extra angular momentum it recieved from the Earth.

So yes, a tether style space elevator still transfers angular momentum from the Earth to the rising car.

And a rising car will not pull down a properly counter-weighted tether style space elevator.

If Janus has opportunity to attend advanced class in orbital mechanics then advantage will be obtained if same does so.

On a rigid link between surface and geostationary satelite, ANY location BELOW geostationary has LESS than orbital velocity.

Therefore, any object below satelite will have less angular momentum than it needs. So, it will give drag back and down upon satelite.

Unless you calculate physics according to Pete Physics, in which momentum is not conserved.

( Although Pete has multiciplicitously posted that momentum is not conserved, he has not posted documentation or equations to back up his postulate, so his expostulation may be safely considered to be dubious. )

Momentum, including angular momentum, in peer reviewed mainstream physics, does not just pop out of hyperspace at random on a large scale.

A payload traveling up the orbit elavator MUST gain angular momentum. Said angular momentum can only come from three sources:

1.: Angular momentum of the Earth's rotation transmitted UP through a rigid moment connection link. Of course this slows the Earth's rotation with each payload that goes up.

2.: Angular momentum of the satelite's rotation transmitted DOWN through a tether hanging from said satelite. Of course this slows the satelite's rotation with each payload that goes up.

3.: In Pete Physics, momentum is not conserved, so momentum can pop out of of hyperspace ( or pop INTO hyperspace ) at whim and speed up or slow down the payload or the satelite or anything else at any time.

If Janus will carefully graphically analyze the situation of a flexible tether trying to pull up a payload then J will be forced to confess that the satelite will become dragged DOWN.

Angular momentum dragged out of satelite MUST be restored by burning of rocket fuel, etc., etc., or else satelite orbit will decay and satelite will fall onto planet.

CANGAS

05-16-07, 02:03 AM

Clumsy, old fashioned rockets have to carry their fuel and reaction mass with them. This means lifting a lot more than just the payload to begin with.

For example, to send 6 tonnes of satellite to geostationary orbit on an Ariane 5G rocket meant lifting 740 tonnes of extra stuff (including 630 tonnes of fuel and oxidizer) off the launchpad.

Climbing a cable has two advantages over rockets - firstly, no reaction mass is required. Secondly, the energy source doesn't need to be carried on board - energy can be supplied electrically through the cable.

This means that the same 6 tonne payload could be lifted to the same orbit at a cost of perhaps 30 tonnes of gasoline (assuming 20% efficiency).

Pete needs to calculate length of cable.

Then Pete needs to calculate electrical resistance of long cable reaching from surface to geostationary satelite.

Then Pete needs to make HONEST calculation of efficiency based upon huge resistance of really long cable.

CANGAS

05-16-07, 02:10 AM

CANGAS

05-16-07, 02:13 AM

It directly addressed the point quoted, which was about energy.

Come on, honest bookkeeper, show us how to tidy the books :rolleyes:

No, no, it is on your responsibility to correctly address the point and do your own correcting.

Although you choose to represent yourself as a baby, I refuse to change your diapers for you.

Pete

05-16-07, 03:19 AM

Pete needs to calculate length of cable.

Then Pete needs to calculate electrical resistance of long cable reaching from surface to geostationary satelite.

Then Pete needs to make HONEST calculation of efficiency based upon huge resistance of really long cable.
That's a good point, although quite different to your original one. We're agreed that the practical engineering problems are tough, perhaps insurmountable... but you seemed to have something to say about the physics involved?

Anyway, the simple (!!) solution to electricity delivery is to use superconductors.

So, my bookkeeping (previously posted) still says that climbing a cable to geostationary orbit would uses 20 times less fuel than riding a rocket.

Your turn, honest bookkeeper.

2inquisitive

05-16-07, 04:23 AM

CANGAS,
1.: Angular momentum of the Earth's rotation transmitted UP through a rigid moment connection link. Of course this slows the Earth's rotation with each payload that goes up.
Of course slowing of the Earth's rotation is due to the transfer of additional angular momentum to the payload + payload carrier over what they had on the Earth's surface.
2.: Angular momentum of the satelite's rotation transmitted DOWN through a tether hanging from said satelite. Of course this slows the satelite's rotation with each payload that goes up.
Of course when the payload carrier goes DOWN the tether, the payload carrier loses a part of the angular momentum in had in the higher location. This lost angular momentum is transferred to the satellite, raising its orbit.
Angular momentum dragged out of satelite MUST be restored by burning of rocket fuel, etc., etc., or else satelite orbit will decay and satelite will fall onto planet.
The angular momentum dragged out of the satellite by the payload itself must be restored. The part of the angular momentum used by the payload carrier vehicle during ascent will be restored to the system during descent.
The physics concerning angular momentum in this system is as simple as shit CANGUS, its the engineering part that is difficult, if not near impossible.

Zephyr

05-16-07, 04:25 AM

Anyway, the simple (!!) solution to electricity delivery is to use superconductors.
Doesn't that require a massive cooling system?

Pete

05-16-07, 06:50 AM

Doesn't that require a massive cooling system?
I wouldn't think so. I suspect that the temperature of the cable would be low enough without additional cooling.

orcot

05-16-07, 06:55 AM

I wouldn't think so. I suspect that the temperature of the cable would be low enough without additional cooling.
The temprature would vary (to?) greatly over it's distance I gues depending on when it's still in the atmosphere or in the night shadow of the earth.

Singularity

05-16-07, 07:43 AM

Ok the original pic/article is in this post http://sciforums.com/showpost.php?p=1374469&postcount=140

And i messed up it a bit to ask u all a good question.

http://hotimg8.fotki.com/a/124_7/91_47/TehterThrow.jpg

I have changed the rotation direction of the tether in above pic. And the question is.

Wont this be better ? I mean the lower orbit is faster than the orbital speed of the tether. So when the tether picks up the payload the speed of the tether should increase as show in the above pic (ie the payload will pull tether in the orbiting direction), and that should help the tether gain some orbital height.

And when the payload is released perpendicular to earth the orbiting speed should keep the payload up after its thrown.

Sorry if u didnt understand the question please ask me as i am sure i have made some goofups here.

D H

05-16-07, 07:56 AM

Do you realize how much energy is involved in this silly diagram? Orbital velocity (LEO) is about 7400 meters/second.

Singularity

05-16-07, 08:17 AM

Do you realize how much energy is involved in this silly diagram? Orbital velocity (LEO) is about 7400 meters/second.

Can u please explain what exactly u mean. :confused:

orcot

05-16-07, 11:19 AM

Okay I'm yust thinking here but a short tether like singus picture could be propelled by tether propulsion (http://en.wikipedia.org/wiki/Tether_propulsion) to a higher orbit, The tether is of suchs lenghts at altitude that it never dips in the atmosphere and stays... on let's say 200 km above the earth at it's closest point while the rest is long enough to effectivly get counter the drag with extra's,
anyway when a cargo arives in a sort of plane a climber decends that holds a aditional 200 km rope (long enough to even reach the surface) the rope decends 120 km a catches it and the craft uses the aditional cable to weild in the cargo... sacrificing orbital momentem that later is regained with tether propulsion/a electromagnetic propulsion or any other method of 0 fuel propuslion

Janus58

05-16-07, 10:31 PM

If Janus has opportunity to attend advanced class in orbital mechanics then advantage will be obtained if same does so.

On a rigid link between surface and geostationary satelite, ANY location BELOW geostationary has LESS than orbital velocity.

Therefore, any object below satelite will have less angular momentum than it needs. So, it will give drag back and down upon satelite.

And any object above geostationary has more than orbital velocity, which why that is where we put the counterweight; So that it more than compensates for any drag caused by any objects below geostationary.

Unless you calculate physics according to Pete Physics, in which momentum is not conserved.

Here's some actual calculations:
Geostationary orbit is at an altitude of 35926 km. So we place the counterweight at 78230 km.

At this distance, making one circuit every 24 hrs, it has a velocity of 6.153 km/sec. Orbital velocity for that altitude is only 2.175 km/sec, so it is obvious that it is traveling faster than orbital velocity.

Now assume that our counterweight masses the same as our elevator car (call it "M".

Sitting on the surface of the Earth the car has a velocity of 464 meters/sec. thus has a momentum of 464m/s * M
The counterweight has a momentum of 6153m/s * M

If we move the car up to the counterweight, the new total momentum of the combined mass will be 464m/s * M + 6153m/s *M = M(464m/s+6153m/s) = 6617m/s * M

Now the actual combined mass will be 2M and since momemtum is velocity times M we can also write the new momentum as 2Mv, with v being the new velocity of our combined mass.

Thus we can write 6617m/s * M = 2Mv

Solving for v, we get

v= 3308.5m/s still greater than the velocity needed to maintain an orbit.

And, we are not limited to making the counterweight equal to the mass of the elevator, we can make it many times larger, resulting in even a smaller change.

A payload traveling up the orbit elavator MUST gain angular momentum. Said angular momentum can only come from three sources:

1.: Angular momentum of the Earth's rotation transmitted UP through a rigid moment connection link. Of course this slows the Earth's rotation with each payload that goes up.

2.: Angular momentum of the satelite's rotation transmitted DOWN through a tether hanging from said satelite. Of course this slows the satelite's rotation with each payload that goes up.

3.: In Pete Physics, momentum is not conserved, so momentum can pop out of of hyperspace ( or pop INTO hyperspace ) at whim and speed up or slow down the payload or the satelite or anything else at any time.

If Janus will carefully graphically analyze the situation of a flexible tether trying to pull up a payload then J will be forced to confess that the satelite will become dragged DOWN.

I already have, as have many others. And the conclusion is that a counterweight will more than compensate for any dragging down effect.

Angular momentum dragged out of satelite MUST be restored by burning of rocket fuel, etc., etc., or else satelite orbit will decay and satelite will fall onto planet.

If you really want to be picky about it, you can maintain perfect angular momentum balance at all times by the simple method of a second elevator.

You break the ascent into two stages. One elevator travels from Earth to the geostationary station, and the other from geostationary station to the counterweight station.

As elevator one rises from the Earth, elevator two lowers from the counterweight. Thus as one removes angular mometum from the structure, the other is adding it back in. Once the cars meet at the center, passengers swap cars, and car one heads back down to Earth while car two climbs back up the the counter weight station.

eburacum45

05-17-07, 06:45 AM

Singularity

05-17-07, 07:40 AM

this section of Wiki discusses angular momentum in the space elevator; on average, the up cars will balance the down cars (if they mass the same), but the cable will flex somewhat;
http://en.wikipedia.org/wiki/Space_elevator#Angular_momentum.2C_speed_and_cable _lean

Seems like u skimped most of the posts here,

whos talking about elevators here anymore, Mr. illuminati.

http://sciforums.com/showpost.php?p=1395053&postcount=170

orcot

05-17-07, 08:44 AM

this section of Wiki discusses angular momentum in the space elevator; on average, the up cars will balance the down cars (if they mass the same), but the cable will flex somewhat;

A couple of clicks brought me to this link (http://en.wikipedia.org/wiki/Skylon)

interesting?

Singularity

05-17-07, 09:52 AM

A couple of clicks brought me to this link (http://en.wikipedia.org/wiki/Skylon)

interesting?

"within 2 days"

Thats something to cheer about :)

Clearly things are getting out of hands for illuminati since the days of television. :m:

Singularity

05-17-07, 10:01 AM

Hey but dont forget this conspiracy.

http://en.wikipedia.org/wiki/Antonov_An-225

Ophiolite

05-17-07, 10:05 AM

Perhaps genius Janus can give hints ( SPECIFIC HINTS ) of how, in practical engineering terms, recovery can be done. I do not believe that it can be possible in practical engineering terms.This is why you are stuck in the twentieth century while we enjoy the fruits of the twenty first.

Singularity

05-17-07, 10:12 AM

HOTOL

http://aeroweb.lucia.it/rap/Champlin95/cha95ag_58.jpg

Actual picture of Myasishchev VM-T

http://www.ussr-airspace.com/catalog/images/al/46/28174632.jpg

Russians were good people,

http://buran.city.tomsk.net/jpg/site0053.jpg

http://buran.city.tomsk.net/buran2.htm

Singularity

05-17-07, 10:25 AM

Actual Photo of Shuttle being lift off from a 747 ,

Hmm, no need of 10, 9, 8, 7, 6, ......

http://www.burlingtonderailed.com/media/1/20060113-125624main_takeoff-m.jpg

orcot

05-17-07, 10:49 AM

Actual Photo of Shuttle being lift off from a 747 ,

Hmm, no need of 10, 9, 8, 7, 6, ......

the shuttle has 2 solid boosters (rockets) the main tank is what the name says it is, a tank it's not a rocket, it simply doesn't have the fuel capacity aeronotics and avionics are 2 completley different things

Singularity

05-17-07, 11:18 AM

the shuttle has 2 solid boosters (rockets) the main tank is what the name says it is, a tank it's not a rocket, it simply doesn't have the fuel capacity aeronotics and avionics are 2 completley different things

Well, well, Nice try. Now, can u just imagine that 747 completely filled with JetFuel ?

http://www.burlingtonderailed.com/media/1/20060113-125624main_takeoff-m.jpg

eburacum45

05-17-07, 11:21 AM

Apart from the cabin, I presume?

eburacum45

05-17-07, 11:34 AM

It is very important to consider all these re-usable spacecraft launch concepts, because they are likely to bring the cost of kg-to-orbit down so much that the research and development for a space elevator will be too expensive a prospect. Several substantial breakthroughs are required before elevators are possible; reusable rockets could be much more cost effective in the medium term.

phlogistician

05-17-07, 11:44 AM

Well, well, Nice try. Now, can u just imagine that 747 completely filled with JetFuel ?

http://www.burlingtonderailed.com/media/1/20060113-125624main_takeoff-m.jpg

Dude, Shuttles have never been launched into space from the back of a 747. Enterprise conducted various glide tests from a 747, and Columbia rode on a 747 when it was delivered prior to it's first launch, but that's it. I guess they would use a 747 to recover a shuttle if it had to use an alternative landing strip.

Singularity

05-17-07, 11:59 AM

Nikelodeon

05-19-07, 06:13 PM

Superb.

Starthane Xyzth

05-21-07, 04:08 AM

By making the precession rate large enough, the Orbital Ring can be made to precess once per day at the rate of rotation of the Earth. The orbit is now "geostationary" without having to be either at the normal geostationary altitude or even in the equatorial plane. A network of orbital ring systems crossing, for example, at the poles, could cover the whole planet with an array of elevators and geostationary ring stations

Fascinating idea, I don't understand why it isn't more widely publicised! Would make good popular sci-fi and a visually impressive movie sequence.:D

But as for the cost of construction... and the public discomfort at the idea of all those huge structures in relatively low orbit, covering several arcs of latitude/longitude... UGH. :bawl: Even given the right technology (Erburacum's mass-produced buckytubes, and cheap mass drivers to launch them) it would be very difficult to get off the ground (pun intended).

Starthane Xyzth

05-21-07, 04:20 AM

HOTOL

http://aeroweb.lucia.it/rap/Champlin95/cha95ag_58.jpg

I believe that's an Antonov-225 (http://en.wikipedia.org/wiki/Antonov_Mriya) carrying the HOTOL- they'd have to build more of them as well, only 1 working model currently exists.

orcot

05-21-07, 07:01 AM

the antanov's wings are in a completly different angle then those of the buran I wonder how how hard it chould have been to fly with that thing on the back

Oli

05-21-07, 07:41 AM

Why would wings at a different angle make it difficult to fly?

orcot

05-21-07, 08:17 AM

aerodynamics perhaps biplane and normal planes are considerbly different things like the tail section, lift,drag, aircurrent interference some things have to be specialy designed overall has to be reinformerd and it will never fly like it is supose to
link (http://en.wikipedia.org/wiki/Biplane)

Oli

05-21-07, 08:30 AM

Definitely, but the HOTOL's wing area would contribute very little to lift as it is not in the airflow from the main wing while being carried.
Any biplane interference that occurred would be at the wing root, the last place to suffer stall or airflow disturbance.
Although they would have had to check for potential loss of control effectiveness/ lift on the empenage due to possible vortices from the HOTOL lifting surfaces.

orcot

05-21-07, 09:01 AM

well it certainly looks like the've redisigned tha tail section for the stearing (it got 2 at the sides in stead of one large in the middle).
I wonder how that effects performance when it's unlouded.
Definitely, but the HOTOL's wing area would contribute very little to lift as it is not in the airflow from the main wing while being carried.
that I'm not so sure off but the lift drag is going to be constant so any computer program can compensate for that

Oli

05-21-07, 09:05 AM

An-225 was designed from the start with a twin tail (presumably to improve control effectiveness in the wake of such a large wing).
Carrying HOTOL is a later idea and would have had no influence on Mriya's configuration.

orcot

05-21-07, 10:01 AM

actually it were stability problems with the rear plane that doomed the project and it's succesor (http://en.wikipedia.org/wiki/HOTOL) (altough the theory was good)

However HOTOL may be scrapped it succesor Skylon (http://en.wikipedia.org/wiki/Skylon) is not wich is basicly the same like he HOTOL but with fixes for the stability problems.... Altough special parts have to be redesigned because of pattent problems... That always cracks me up a goverment pays some scientist to design some crucial part and he does so for a couple of hunderd thousand dollar but he keeps the patent so that they can't use the stuff the've paid for in the next version unless they pay those couple of hunder thousands again that are by then outdated because evolution of the hardware makes it so that completly redesigning them is cheaper...
anyway $3000/kg... relativly spoken that's cheap as cheap as a first generation space elevator a russian proton does abouth 4300 and 9350 for a space shuttle for comparison

orcot

05-24-07, 09:16 AM

the falcon (http://en.wikipedia.org/wiki/SpaceX#Maiden_test_flight_of_Falcon_1) looks nice to

a decrease in costs from a average 8800$/kg to 1300$/kg
initially and perhaps as low as 1100$/kg in the further future. (It apears previus costs mentioned of $4,000 where costs in pounds)
It would become commercial between 2008-2010 and it apears NASA is willing to invest up to 278$million (http://www.spaceflightnow.com/news/n0608/18cots/)in it (if it achieves certain goals) what is great for it's financial future.

Janus58

05-26-07, 03:48 PM

Well, well, Nice try. Now, can u just imagine that 747 completely filled with JetFuel ?

Actually, I can. A 747-400 freighter completely loaded with fuel (cargo space included), would only be, under the best of circumstances, 28638 kg under maxiumum take off weight. Add the empty weight of the shuttle (75,000 kg), and it will never get off the ground.)

Besides that, of what use is adding fuel to the plane? All that would do is increase the range of the plane, it would do nothing towards raising the max speed or its ceiling. If anything, the increased fuel weight would lower the plane's ceiling.

Fraggle Rocker

05-26-07, 06:16 PM

Space elevator is a conspiracy to keep humans away from cheap space travelHuh? The whole point is to make space travel cheaper. We won't need spacecraft that are sturdy enough to withstand takeoff and landing in Earth's gravity yet powerful enough to reach escape velocity from that gravity. Those spacecraft are enormously expensive. Most of their fuel is expended on moving the bulk of the craft itself rather than the passengers and other contents. With an elevator all you have to do is transport the people and goods to the top--which can be done very energy-efficiently by making sure you have a load coming down every time one goes up. Then you launch an absurdly flimsy spacecraft with a payload much larger than itself so your fuel is expended on doing real work instead of moving the ship back and forth.

A space elevator is a very sensible idea. The only drawback is the possibility that some Religious Retards will find an excuse to blow it up, probably while there are ships out that will now have no way to get their crews back to earth.

Starthane Xyzth

05-29-07, 03:37 AM

A space elevator is a very sensible idea. The only drawback is the possibility that some Religious Retards will find an excuse to blow it up, probably while there are ships out that will now have no way to get their crews back to earth.

Plus the obvious "light pollution" aspect of having one or more gigantic, permanent towers stretching up to the height of geostationary satellites - let alone a solid, manmade ring encircling the Earth. Ground-based astronomers would absolutely HATE it. :mad:

Pete

05-29-07, 07:14 PM

How much light do you expect it would produce, Starthane? And how visible do you think it would it be from 35000 km away?
I don't see ground based astronomers complaining about light pollution from existing satellites.

Starthane Xyzth

05-30-07, 03:43 AM

Janus58

05-30-07, 10:47 AM

The top of a space elevator would have to act as a shipyard, a commercial spaceport - be a massive, fixed installation, an orbital city where thousands could live and work. What else would justify the expense of building the elevator? Something 25 miles across orbiting Earth at the same diatance as the Moon would shine like a 1st-magnitude star; this would be a lot closer.

If the various space elevators did indeed give rise a full planetary ring, it would look thin but extremely bright, dominating the night sky. Even when in the Earth's shadow, its countless artificial lights would no doubt still be visible from the ground.

That depends on it's albedo. While it might be that bright if its albedo is the same as the moon's, it need not be that bright. I would expect that any surface that catches any large percentage of sunlight would be covered with photocells for energy production and would reflect very little.
Besides that, 25 miles across seems a little excessive. You could put a population of 150,000 in a sphere just 2km across, without crowding them (1 person per every 8000 m^2)

What I was really thinking of, though, was the elevators themselves. Their lower portions, reaching down to the surface, would clearly be very prominent.

At night, when light pollution would be a problem, the lower 16,000 km of the elevators would be in the Earth's shadow.

But I assure you: personally, I'd consider the light pollution a very small price to pay for opening up the Solar System! If it can be safely and cleanly built some day, I'm all for it. :D

Besides that, just how much ground-based optical astronomy would still be done at this time?

phlogistician

05-30-07, 11:27 AM

Besides that, just how much ground-based optical astronomy would still be done at this time?

Well, since this would afford cheap launches of Hubble successors, I should think astronomers would be rather happy about it. Well, apart from the loss of trips to Mauna Kea for observations :-) !!

Starthane Xyzth

05-31-07, 03:45 AM

That depends on it's albedo. While it might be that bright if its albedo is the same as the moon's, it need not be that bright.

The Moon looks brilliant silver in our night sky, but it is actually a very dull, grey rock, reflecting only about 7% of incident sunlight. A metallic or even carbon-fibre structure might be more reflective than this.

Besides that, just how much ground-based optical astronomy would still be done at this time?

Ground-based observatories will always have a place, even if eventually they're only amateur. A lot of important discoveries (eg. comets) have been made by amateurs.

orcot

06-01-07, 07:52 AM

The Moon looks brilliant silver in our night sky, but it is actually a very dull, grey rock, reflecting only about 7% of incident sunlight. A metallic or even carbon-fibre structure might be more reflective than this.

The moon is 3000 km in diametre would any such a long structure be wider then 1 metre on average

Ground-based observatories will always have a place, even if eventually they're only amateur.
... not for a very long long time ground baseobservatories are going to stay useful for a very long time

CANGAS

06-03-07, 12:18 AM

I wouldn't think so. I suspect that the temperature of the cable would be low enough without additional cooling.

But would you ever be able to provide rigorous calculated numbers to PROVE your suspicions?

No way.

CANGAS

06-03-07, 12:24 AM

And any object above geostationary has more than orbital velocity, which why that is where we put the counterweight; So that it more than compensates for any drag caused by any objects below geostationary. Here's some actual calculations:
Geostationary orbit is at an altitude of 35926 km. So we place the counterweight at 78230 km.

At this distance, making one circuit every 24 hrs, it has a velocity of 6.153 km/sec. Orbital velocity for that altitude is only 2.175 km/sec, so it is obvious that it is traveling faster than orbital velocity.

Now assume that our counterweight masses the same as our elevator car (call it "M".

Sitting on the surface of the Earth the car has a velocity of 464 meters/sec. thus has a momentum of 464m/s * M
The counterweight has a momentum of 6153m/s * M

If we move the car up to the counterweight, the new total momentum of the combined mass will be 464m/s * M + 6153m/s *M = M(464m/s+6153m/s) = 6617m/s * M

Now the actual combined mass will be 2M and since momemtum is velocity times M we can also write the new momentum as 2Mv, with v being the new velocity of our combined mass.

Thus we can write 6617m/s * M = 2Mv

Solving for v, we get

v= 3308.5m/s still greater than the velocity needed to maintain an orbit.

And, we are not limited to making the counterweight equal to the mass of the elevator, we can make it many times larger, resulting in even a smaller change.
I already have, as have many others. And the conclusion is that a counterweight will more than compensate for any dragging down effect.

If you really want to be picky about it, you can maintain perfect angular momentum balance at all times by the simple method of a second elevator.

You break the ascent into two stages. One elevator travels from Earth to the geostationary station, and the other from geostationary station to the counterweight station.

As elevator one rises from the Earth, elevator two lowers from the counterweight. Thus as one removes angular mometum from the structure, the other is adding it back in. Once the cars meet at the center, passengers swap cars, and car one heads back down to Earth while car two climbs back up the the counter weight station.

At halfway, up and down cars stop by magicke, or, does power become used to stop motion of cars?

CANGAS

06-03-07, 12:34 AM

CANGAS,

Of course slowing of the Earth's rotation is due to the transfer of additional angular momentum to the payload + payload carrier over what they had on the Earth's surface.

Of course when the payload carrier goes DOWN the tether, the payload carrier loses a part of the angular momentum in had in the higher location. This lost angular momentum is transferred to the satellite, raising its orbit.

The angular momentum dragged out of the satellite by the payload itself must be restored. The part of the angular momentum used by the payload carrier vehicle during ascent will be restored to the system during descent.
The physics concerning angular momentum in this system is as simple as shit CANGUS, its the engineering part that is difficult, if not near impossible.

In case you were asleep when you were reading my previous posts, 2inq., I will repete my opinion: THE CONCEPT OF AN ORBIT ELEVATOR CONTAINS A RAFT OF HUGE AND SEEMINGLY INSOLVABLE practical engineering problems.

What part of my post: "practical engineering problems" is it that you are having the most trouble understanding?

guthrie

06-03-07, 05:07 PM

So you claim. I understand that many engineers disagree with you. However, not being personally aqainted with their work, I cannot demonstrate this to you.

Pete

06-03-07, 08:33 PM

But would you ever be able to provide rigorous calculated numbers to PROVE your suspicions?
Perhaps, if I chose to. I chose not to, which I why only I offered it as a suspicion.

At halfway, up and down cars stop by magicke, or, does power become used to stop motion of cars?
What do you think, CANGAS?
And can you provide "rigorous calculated numbers" to support your thoughts?
:rolleyes:

Oli

06-04-07, 07:35 AM

I will repete my opinion: THE CONCEPT OF AN ORBIT ELEVATOR CONTAINS A RAFT OF HUGE AND SEEMINGLY INSOLVABLE practical engineering problems.

Really? What would they be?

Pete

06-04-07, 09:17 AM

Definitely huge. Unsolvable? I wouldn't dare to guess.

Materials,for one. Spinning enough carbon nanotube to make a 35000 km cable that might be tens of metres thick at the top is a tricky proposition.

Power delivery, for another. Laser power? Superconductors? Both rife with difficulties.

Managing traffic. Not just traffic up and down the cable, but also satellite traffic that will collide with the cable if not managed.

Constructing a base tower.

Disaster management, including earthquakes, thunderstorms, solar flares, and meteorites.

Definitely huge, huge practical engineering problems. The Apollo program doesn't even come close.

Oli

06-04-07, 09:24 AM

Definitely huge. Unsolvable? I wouldn't dare to guess.
Huge, yes. Unsolvable, no.
Not with money thrown at it.
It's just bigger, not necessarily more difficult. Quantitive differences, not qualitative.

Pete

06-04-07, 09:32 AM

Oli

06-04-07, 09:40 AM

I'm not so sure. Maintenance is one thing that strikes me as quite different qualitatively. How do you maintain a 35000km cable under extremely high tension and under constant bombardment from solar wind and micrometeorites?

This is not stuff that has been done before... it's not just scaling up existing tech. There are brand new problems to solve.

Yeah new problems are the fun of engineering. I'm not sure solar wind would be one them though, haven't looked too closely at it other than one or two "back of the envelope" projects.
I vaguely remember that the "high tension" is mostly due to the weight of the cable below. And that it reaches a maximum value and then tapers off as the cable approaches GSO altitude.
IIRC Pournelle and Niven did some hard (ish) thinking on this, with calculations and suggestions. But I can't remember which book it was in. Damn.

iceaura

06-04-07, 04:39 PM

Oli

06-04-07, 04:42 PM

A cable that long, if somehow (huge static electricity buildup, mishap?) it broke at about 30km, could potentially take out city buildings on the other side of the planet from its base.

Pretty spectacular possibilities.

In Kim Stanley Robinson's Mars Trilogy (Red, Green, Blue) someone snapped the cable during a civil war and wasted most of the domes and colonies that were in-line with its path as it fell.
Doesn't bear thinking about. :eek:

Starthane Xyzth

06-07-07, 09:47 AM

That would be the ultimate whiplash. A kind of global flogging!

orcot

06-07-07, 02:50 PM

the beam would be around 5 times longer then the planet I'm sure the centrifugal forces together with friction would make it snap no matter how heavy/strong it is, so the mayor part is going to fly away on it's own

CANGAS

06-08-07, 12:01 AM

G'day, mates. I've just had a swell idea.

You (all) post a list of the TOP TEN practical engineering problems indigenous to the erection and operation of a convenient and economical and safe orbit elevator and then you (all) post your thoroughly worked out design engineering solution to each problem.

Of course, if you go over ten, you have my permission to post all 1,010, or one Gillian and ten, or, however many serious problems you fumble and stumble across.

Then you and me and cute little baby head Pete and Dave and everybody can read and weep or perhaps laugh with joy about how easy and cheap and safe it is going to be to get off of Earth by an orbit elevator.

Just one idea for you (all) to think about: 22,222 miles of nanotube tether, levitating motors, superconductor cable, refrigerant piping, payload cars, payload cargo, payload passengers, etc., etc., etc., etc., all of which is beneath geostat orbital altitude and therefore is moving slower than orbital velocity, enjoying the moment that the tether snaps and falls to the surface.

Major disaster?

How 'bout it, mates? Who's posting number one?

orcot

06-08-07, 04:32 PM

How 'bout it, mates? Who's posting number one?
The problems are a equation http://www.zadar.net/space-elevator/.

Look their are things that aren't yet possible today, but todays limits are not the limits in 10 or 20 years, and it's theoreticly possible, the fact is that I personally (opinion) have little faith in alternative "cheap" space flight...
Besides even if the space elevator would be replaced by a cheaper way of transportation your still going to gave nano tubes in your computer by 2010-20

Starthane Xyzth

06-13-07, 03:28 AM

http://www.zadar.net/space-elevator/.

your still going to gave nano tubes in your computer by 2010-20

Thanks for the link, I'll read it avidly.

But do you think carbon nanotubes will, sooner or later, replace copper wires? No more soldering... there goes half of my career plans! :(

orcot

06-13-07, 02:10 PM

But do you think carbon nanotubes will, sooner or later, replace copper wires?
... Not anytime soon. But perhaps there wont be any copper anymore in chips in a year or 10 http://sanjose.bizjournals.com/sanjose/stories/2005/06/06/daily32.html.
Anyway where there is a market there is budget for further development and where there is mass production costs plumit

http://en.wikipedia.org/wiki/Potential_applications_of_carbon_nanotubes
Technology that can be used to make water tight clothes, solar cells, water filters and electronics... that's a wide range of rechearge all contributing on what eventualy could be used to make a space elevator

CANGAS

06-19-07, 03:16 AM

Oli

06-19-07, 05:59 AM

Hard luck, it's not pseudoscience: it's engineering.

orcot

06-19-07, 12:35 PM

In view of the fact that no responsible person on the planet would agree to the attempted construction of a structure that would cause a worldwide catastrophe when it fails

What's a worldwide disaster? I imagen that a nuclear meltdown somewhere in doel would spread a radioactive cloud over antwerp and Rotterdam effectivly killing millions and cutting of a enormous amount of the European shipyard... doel ever heard of it? Almost nobody does... how much structures where build that would cause a worldwide catastrophe... considering oil pipelines, nuclear arsenals honnestly I would now how to begin, it's not that there are douzens of examples you would have to categorise them to keep track?

Besides... it's not pseudo science today it would still have to be build by unobtanium but the math is sound the problems can be overcome. The quistion is when exactly will it be possible to build the necesairy materials and if it by that time is still the most economic possibility. Money would not be a problem unless costs go over what some rediculous amound like 250 billion

Ophiolite

06-21-07, 05:15 AM

In view of the fact that no responsible person on the planet would agree to the attempted construction of a structure that would cause a worldwide catastrophe when it fails, the subject of an orbit elevator is interesting fantasy, but is in the same Pseudoscience category, according to the rules of this physics forum, as UFOs.

Since any attempt to build one ( an orbit elevator ) would be restrained, the concept is untestable and must be considered Pseudoscience according to this physics forum.This is typical of the blinkered thinking that has infected humanity since Ug said to Og, "Pointed sticks won't help you catch antelope, they'll just poke your own eyes out if you're careless."

Many of the problems of the space elevator have been identified, described and quantified. That is not pseudoscience.

Some of these problems have been solved, at least on a theoretical basis. That is not pseudoscience.

Other problems have had their solutions sketched out, with the necessary research and development outlined. That is not pseudoscience.

Starthane Xyzth

06-27-07, 08:32 AM

orcot

09-05-07, 04:28 AM

So if foud a nice site with doomsday result if such a cable would snap
http://www.mit.edu/people/gassend/spaceelevator/breaks/index.html
Yust wondering would it not be simple enginering to place some sort of cable cutter ad the base of the cable that would launch the elevator in space before it whips the planet?

CANGAS

09-09-07, 04:22 AM

This is typical of the blinkered thinking that has infected humanity since Ug said to Og, "Pointed sticks won't help you catch antelope, they'll just poke your own eyes out if you're careless."

Many of the problems of the space elevator have been identified, described and quantified. That is not pseudoscience.

Some of these problems have been solved, at least on a theoretical basis. That is not pseudoscience.

Other problems have had their solutions sketched out, with the necessary research and development outlined. That is not pseudoscience.

The worst is yet to come for fanciful daydreamers who live in world of hallucinations.

Have you ever heard of Faraday law of induction?

Give it some thought ( OK, you can give it a lot of thought.

Sweet dreams.

orcot

09-09-07, 05:10 AM

http://en.wikipedia.org/wiki/Faraday's_law_of_induction

Because of the symmetry and unique electronic structure of graphene, the structure of a nanotube strongly affects its electrical properties. For a given (n,m) nanotube, if n - m is a multiple of 3, then the nanotube is metallic, otherwise the nanotube is a semiconductor. Thus all armchair (n=m) nanotubes are metallic, and nanotubes (5,0), (6,4), (9,1), etc. are semiconducting. In theory, metallic nanotubes can have an electrical current density more than 1,000 times greater than metals such as silver and copper.[16]

It can proberly handle a large voltage altough it's best to keep it away from lighning prone area's. There are proberly tricks and sorts to deal with this altough if the magnetic field is only 30 to 60 microteslas this might not be that much of a problem

By the way I might be wrong abouth this but the space elevator stands static seen from earth do you actually get electromagnetic induction if both the magnet and the conductor are rotating at the same speed?

CANGAS

09-09-07, 06:14 AM

http://en.wikipedia.org/wiki/Faraday's_law_of_induction

It can proberly handle a large voltage altough it's best to keep it away from lighning prone area's. There are proberly tricks and sorts to deal with this altough if the magnetic field is only 30 to 60 microteslas this might not be that much of a problem

By the way I might be wrong abouth this but the space elevator stands static seen from earth do you actually get electromagnetic induction if both the magnet and the conductor are rotating at the same speed?

Do yourself a favor and bone up on whether a rotating magnet and its field lines rotate in synchrony.

Helpful hint: NOT.

No kidding. And this has been proved many, many, many years ago and openly published in physics literature. Though perhaps not in your ordinary literature.

Do some research and then do some rigorous calculations and then tell me how many thousands upon thousands of volts you dreamily believe that the orbit elevator can be be designed to tolerate.

orcot

09-09-07, 06:47 AM

Okay give me a brake I havent seen inductions and stuff for 5 years. So the earths magnetic fields rotates ad a different speed then the planets surface and exactly for this reason we have a magnetic field in the first place...
Do you have any info on the effects of this on power lines here on the surface of the earth (because those chould be affected as well) they might be many times shorter but their diagnally on the earths surface so they chould cross more fieldlines (do they actually? I forgot Do you get a EM if you move a conductor up and down a magnet in stead of letting it rotate around it?)
Do some research and then do some rigorous calculations and then tell me how many thousands upon thousands of volts you dreamily believe that the orbit elevator can be be designed to tolerate.
Well thousands and thousands if it proves necesairy, it's yust a problem to keep the ampere low. (sorry but I don't have the data to perform any rigorous calcs

I'm guessing here but any climber is proberly going to be electrical perhaps it can use the energy in combination with whatever it uses as a energy source

CANGAS

09-09-07, 07:07 AM

Okay give me a brake I havent seen inductions and stuff for 5 years. So the earths magnetic fields rotates ad a different speed then the planets surface and exactly for this reason we have a magnetic field in the first place...
Do you have any info on the effects of this on power lines here on the surface of the earth (because those chould be affected as well) they might be many times shorter but their diagnally on the earths surface so they chould cross more fieldlines (do they actually? I forgot Do you get a EM if you move a conductor up and down a magnet in stead of letting it rotate around it?)

Well thousands and thousands if it proves necesairy, it's yust a problem to keep the ampere low. (sorry but I don't have the data to perform any rigorous calcs

I'm guessing here but any climber is proberly going to be electrical perhaps it can use the energy in combination with whatever it uses as a energy source

You are doing way to much guessing.

If you are hoping to be a positive spokesman in favor of an orbit elevator then you are fired for being an abject failure.

An orbit elevator tether composed of carbon nanotubes having a metallic conductance will enjoy an induced voltage of WOO HA !

The induced voltage will induce a current of WOO WOO HA HA !!

The induced current will make a back torque of prodigeous proportions.

The orbit elevator will be stopped dead in its tracks before it can get started almost.

Sorry, investors.

orcot

09-09-07, 07:54 AM

If you are hoping to be a positive spokesman in favor of an orbit elevator then you are fired for being an abject failure.

My answer is simple no negative effect chould be expected by such a small force unless proven.
Show me the formula that explains these massive build ups in a 30 microteslas enviroments with a tether that cuts a min on field lines ad such a low speed

CANGAS

09-09-07, 08:09 AM

My answer is simple no negative effect chould be expected by such a small force unless proven.
Show me the formula that explains these massive build ups in a 30 microteslas enviroments with a tether that cuts a min on field lines ad such a low speed

I do not need to show you anything. If anyone is so naive to think that an orbit elevator could even get started, much less continue to operate for more than a moment, and if they are so stupid as to invest even one penny in such a fool's errand, then that is their business.

All of my money is elsewhere.

orcot

09-09-07, 08:34 AM

I do not need to show you anything. If anyone is so naive to think that an orbit elevator could even get started, much less continue to operate for more than a moment
With current materials no but by perfecting those that we have in a way that we can resenably prodict so yes but it might take a decade or 2 (before any mission to mars).
And it will be the only economic way up in space for the next +century

CANGAS

09-09-07, 09:13 AM

With current materials no but by perfecting those that we have in a way that we can resenably prodict so yes but it might take a decade or 2 (before any mission to mars).
And it will be the only economic way up in space for the next +century

It is not a matter of current materials.

It is a matter of basic physics, as has been widely publicised for two centuries. A conductor moving in a magnetic field enjoys a back torque.

The back torque brakes the moving conductor. Is there a bushman so dumb that he does not know this?

The moving conductor, the orbit elevator tether, would be braked from the first second, and so would retard the entire orbit elevator assembly so as to reduce its orbit velocity to zero and send it falling upon the hapless earth below.

There will never be any Hilton ledges on the orbit elevator, no whatevever suites, because there will never be any orbit elevator except for the one braked to an instant stop and falling upon the helpless citizens of the planet below.

There will be criminal charges against anyone presently instigating such a scenario.

And criminal fraud charges against anyone who invited investment into such an truly absurd scheme.

orcot

09-09-07, 10:22 AM

A simple refrigerator magnet is 50 G. The earth's magnetic field is 0.5 G (g standing for gausse (source (http://www.nevusnetwork.org/mritech.htm))
Really the magnetic field isn't that much of a problem even the plasma flows that move along to magnetic field are a far larger concern then the magnetic field itself

A conductor moving in a magnetic field enjoys a back torque.
Many things would create a "back torque" however the cable will always be stressed and the compensation energys would come from the earth angelur momentum... It simply can't stop unless it get's loose from the earth or the earth stop spinning(source (http://en.wikipedia.org/wiki/Space_elevator#Angular_momentum.2C_speed_and_cable _lean))

The moving conductor
pleace not that the cable would be static with the earths surface so your moving conductor wreally is the same like for example the power grid network

eburacum45

09-15-07, 12:43 PM

Try this link;
http://www.isr.us/SEScienceFAQs.asp#6
Will the ribbon produce an electrical current?

The last space shuttle-tether experiment, which unspooled about 12 miles of cable, generated thousands of volts of electrical potential and kilowatts of power, burned through the insulation of the cable, and generated a tremendous explosive arc of electricity, that snapped the tether. Now imagine a 60,000-mile-long cable and its electrical-generating capacity and you begin to see the disastrous potential.

There are several aspects to this question. An electrical current might be produced in several ways: 1) due to the electrical properties of Earth's atmosphere, 2) collection of the space plasma and 3) due to the movement of the ribbon relative to the natural magnetic fields near Earth.

1) Earth's atmosphere consists of voltage differentials and charge build-up in association with storm activity, in the ionosphere and even on a clear blue sky day. The last is easiest; the voltage potential set up there can be many volts but is over a large distance and based on the resistance of the ribbon would produce little current or difficulty. Storms produce high voltage differences, enough to produce lightning which can damage the ribbon. We have selected an anchor location in an area that has essentially no lightning and very little storm activity. With our mobile anchor, we will be able to avoid the rare storm. In the upper atmosphere there can also be charge and voltage potential build up. In the upper atmosphere (ionosphere) the density of plasma is low and there will be poor coupling between the plamsa and our ribbon. We will have some charge build up and small current flow but it will be comparable to a small household battery. One area we need to investigate further is sprites or breakdown events in the extreme upper atmosphere.

2) In space, there are plasmas that can deposit charge on satellites and our ribbon. As above, the density of this plasma is very low and a small amount of charge will be collected on our ribbon. We also expect both positive and negative charge to be deposited on the ribbon which would reduce the net charge build-up. If one charge preferentially builds up, this will raise the potential of the ribbon, pushing away more of this charge and attracting the opposite charge, which will limit the net voltage build-up. The total charge and voltage we expect and the length and resistance of the ribbon again make the currents much smaller than what you could get from common small batteries.

3) The third place where currents can be produced is when a wire is dragged through a magnetic field. This is how commercial electric generators work. To produce electricity, you need a strong magnetic field and a high velocity. This has been demonstrated on orbital tethers traveling at 11,000 mph through Earth's magnetic field, high voltages have been produced (1000's of volts). (3a) In our case, our ribbon is essentially stationary relative to Earth's magnetic field so, again, very little current will be produced. (3b) The upper end of the ribbon will be in space and be moving relative to the interplanetary magnetic field, but since this magnetic field is very weak little current is produced here as well.

If you add up all of these currents and voltages, you end up with nothing that will be problematic with the exception of the lightning. So as long as we avoid lightning and the storms associated with it, we will get very little current flow or trouble from this area. You can think of most of this in terms of a conventional TV tower. Related to most of the topics discussed above (1 and 3a) we will experience the same voltages and millions times less (due to the relative sizes) current as a TV tower. Several colleagues had hoped that we might produce electric power from the ribbon but from what we have found power generation from the ribbon will take a lot of work and design modifications to produce much of anything.

-Dr. Brad EdwardsMy bolding.

and this one
http://isr.us/spaceelevatorconference/FINAL_Conference_Presentations/TetherTechnology/Final%20Spadaro_SE2004.ppt
Conclusion

Ionosphere has several potential interaction mechanisms w/ the ribbon
Global electric circuit – Ribbon would have higher conductivity than air. Small current flows most likely creating a localized effect without significant heating issues
Equatorial Electrojet interaction – Avoid certain longitudes
Triple point effect – Needs to be studied
Storm clouds can initiate a current flow along the ribbon
Significant heating may occur compromising the ribbon
Coatings may be necessary
More research needs to be conducted

Interesting stuff.

Zephyr

09-15-07, 03:00 PM

Interesting. I read awhile ago that carbon nanotubes may not have the necessary tensile strength (per weight). Is there any more recent info on this?

orcot

09-16-07, 03:57 AM

Interesting. I read awhile ago that carbon nanotubes may not have the necessary tensile strength (per weight). Is there any more recent info on this?

I don't really have a proper source with exact data but it rather depends, anyway where net there for a earth tether but no revulutionairy new technologies have to be invented to build one for earth.

For the moon however you can get away with kevlar (because the lower gravity) and it would only take a launch weight from earth of 6100 tons... (that's a lot) But aperently you would get a desend return from this (http://en.wikipedia.org/wiki/Lunar_space_elevator)

As of yet it would also be impossible to build one on Mars, considering martian GEO is around half the distance then in earths case (so the elevator only has to be half as long) and there is only 38% gravity were proberly pretty close to reaching this but it tells a lot abouth any potential terran space elevator

17,000 km 35,786 km