Alternate means to leaving gravity well, as opposed to launches

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Cretin42, Oct 28, 2001.

  1. ElectricFetus Sanity going, going, gone Valued Senior Member

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    18,140
    eburacum45,

    why don't you look at my site, they found the solution.
    1. for everthing you bring up, bring something down.
    and/or
    2. Use the earths magantic feild as propulsion for LEO tethers.

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  3. eburacum45 Valued Senior Member

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    Very good link; I have read it, a while back; and linked to it too, as I recall.

    I think we might well be using tethers in the next fifty years or so-
    but I wonder if there are not hidden safety issues to do with such momentum transfer and powerful magnetic/electric fields.
     
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  5. RawThinkTank Banned Banned

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    Is the below possible ? if not then telling how to make it possible is compulsory.

    Create a SPACE HANGER, Its a pulley hanging form space just into the above atmosphere. The pulley hangs from a geostationary Space Taxi Station. A small Space Taxi is released up using a very very large helium balloon. This Space Taxi rises up enough to reach the end of the pulley, flys towards using jets and attaches itself to the pulley, then it is pulled up by the Space Taxi Station.

    All this is done with minimum fuel so what say ?

    PS. A compressor can be used to bring the balloon back on earth.
     
    Last edited: Aug 20, 2004
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  7. ElectricFetus Sanity going, going, gone Valued Senior Member

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    why not just make the pull go all the way to the ground?
     
  8. Mr. Chips Banned Banned

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    The moon has gravity, sufficient to render launching vehicles from there for solar system study or engineering as quite inefficient especially when compared to launching them from the Lagrange points and using other such points for gaining momentum in an idea that has already been used to launch a satellite into a polar orbit with much more efficient fuel use.

    Dinosaur, yes, lets use fusion energy, from the sun. One serious company with knowledge of the recent breakthroughs in carbon filament manufacture states that with sufficient funding they could have a space elevator constructed in as little as 15 years, powered by solar power. A low orbital platform suspended from helium balloons with an elevator to the platform that can launch small payloads into space is considered feasible now using available materials and to cost very little (search for project beanstalk)..

    jamesm, send an elevator down at the same time as you put one up on a space elevator (with matching mass, lots of stuff we can best manufacture in orbit is needed on the planet) and you will cancel out the loss of orbital velocity. .

    Consider, the main thrust of space exploration and access has been military in nature. I contend that the major barrier to facilitating humanity to become a space based species is the nature of our society, concerned more with forcing opinions than finding jointly rewarding solutions. Science is not respected in a world where power mongering is the major occupation. Technologies that empower people, that increase liberty, are at odds with the oligarchies that rule. Most are too immersed in the propaganda to see how general policies are most often an attempt to impose rather than consolidate. Mutual reward is not our priority. Suspect this to change or kiss your ass goodbye.
     
  9. RawThinkTank Banned Banned

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    It seems NASA has deliberately not done what has been thought here by mere armatures.

    May be they wanted to fool US citizens for creating weapons grade technology with their tax money.
     
  10. Zarkov Banned Banned

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    Look guys all this theorising is a total waste of effort... the reality is it is too complicated and more complicated than stupid reaction rocket engines....

    Where are you going to get material that conducts electricity that is strong enough to dangle 42,000 kms and thick enough to conduct mega amps, ( because there is a differential electric potential all the way down to the ground )

    First you had better learn how to harness lightning,,, this is a small fish compared to the whale you are dreaming about.

    Inertial drives are a reality, and this makes for "driving" (as per a car) into space, with almost no effort, maybe a thousand HP per ton per hour (derived from IC engine figures, not puff out the arse as in rockets)

    But it is good to dream, dream on you crazy diamonds....
     
  11. Mr. Chips Banned Banned

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    Latest Discover magazine has an article on space elevators, gaining momentum and support despite it being a virtually unmentioned subject in most circles. The NASA researcher in the article estimates that we can build them in less than 15 years. A specific detailed plan and art work are presented. Its a good read.
     
  12. Zarkov Banned Banned

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    >> I see combination of a 2 kilometers magnetic acceleration track, combine with a laser driven engine to get past mach 7, and then engage onboard scamjet engine to
    get to orbit at full velocity, get back to earth


    The major problem as I see it, for space craft is vibration and extreme forces on ascent and re-entry... basically by all conventional methods the craft is destroyed quite quickly.

    Controlled ascent (at say 1g, much like an elevator ) and controlled descent are the first priority and this level of control of gravity can only be achieved by an inertial engine. Controlled max LOW vel in the atmosphere is also a prime consideration.
    Basically if you havn't got FINE control you are sitting on a bomb....

    Fuel is negligable in an inertial drive as coupling to mass movement is efficiently direct.

    Preferrably ascent and descent should be from wherever to wherever.... not confined to an exclusive site... this is more critical if planetary exploration is to be efficiently achieved.
     
  13. Boris2 Valued Senior Member

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    any designs on the drawing board for an inertial engine Zarkov? anywhere on the net?
     
  14. vslayer Registered Senior Member

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    has anyone thought of a good old slingshot?
     
  15. Mr. Chips Banned Banned

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    Latest Discover mag has a short article on the successful testing of a pilotless ramjet to mach 7. It was launched mounted on a high speed missile/jet that was in turn mounted under a Boeing 707. It is thought as a possible way to deliver payloads to low Earth orbit. Don't think I'd ever want to ride on such a thing.
     
  16. talk2farley Registered Senior Member

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    I don't like the magnetic railgun system much. Great for building destructive cannons with dumb payloads, not so great for getting anything organic into orbit (Acceleration to an orbit-making velocity over a relatively short distance, such as a cannon barrel, will surely kill the unfortunate souls on board). Also not so great for launching delicate satellites or any electronics whatsoever; the itense electromagnetic fields will fry all the circuits.

    The space elevator is creative, but well within the bounds of sci fi. Fifteen years suggests an overactive imagination. First of all, the materials to support the weight of the system do not exist. Second of all, in order to maintain a geostationary orbit, one must have a conventional thrust mechanism onboard the anchor to counter the pull of whatever climbs the tether. Granted, you might see a cost savings in the short term, but not in the long.

    The only idea of any merit is the one least discussed: the laser (or microwave) powered microvehicles. Also, one idea that has not yet been mentioned but has merit for lengthy voyages (say, sending probes and satellites to the outer planets) is the solar sail technique. Use the pressure effect of solar wind to propel a small craft more or less indefinitely, albeit slowly. Not to mention it has a certain poetic eloquence, as a throwback to the sailing ships of yesteryear.

    However, once in space, conventional rockets will rule the day for the foreseeable future (even speaking in sci fi terms), at least when the goal is to get your perishable payloads (say, human beings) across great distances in the least possible time. Plasma rockets may replace their chemical counterparts (they are far more fuel efficient, and have a much greater energy potential), as the technology to create and contain plasma matures.
     
  17. talk2farley Registered Senior Member

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    I'm not a big fan of hydrogen fusion, either. The only method for theoretically containing the intense heat given off by the reaction would be extremely powerful electromagnetic fields. Unfortunately, the energy required to maintain the shielding would likely bleed a signifigant portion of the energy gained, at least using the methods known or imagined today. Although, using planets themselves as spaceships is a creative idea. In such a scenario, why not use the core itself (which comes prepacked as a self-sustaining, self-containing, energy rich system). Simply drill a hole, and funnel a small amount of bleed energy, just enough to defeat the force of gravity holding the globe in place. Given a long enough time table, you wouldn't need much, and as the system is has an atmosphere, gravity, natural resources, etc. time is one thing you have plenty of. Too bad the builders will not live to see the fruits of their labors.

    Anti-matter fusion, as another option, solves your problems with excessive heat (to a degree, of course). However, creating and sustaining the anti-matter fuel is a problem, as is the amount of energy lost to other types of radiation (gamma and x-ray), which too must be shielded.
     
    Last edited: Jun 15, 2004
  18. Mr. Chips Banned Banned

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    As far as I can tell from that Discover article they missed a recent innovation that promises stringing the carbon nanotubes togethor to make large ribbons sooner so that 15 years may be an over estimate (the researcher suggests less than 15 years himself). A thread sized diameter suspends a car. The NASA researcher has a few kilometers long rope made of the stuff. To start, the ribbon is unreeled to descend to the surface at the same time the other half is released in the other direction. The base is on a floating platform so it can be moved to avoid space junk. The ribbon suspends itself enough to support a few tons climbing up without any further counter weight. For more traffic, some of the climbers are parked at the mid point and beyond to increase the amount that can be transferred up the ribbon (thinner than a newspaper). Apparently, at the end, items released will have a velocity sufficient to carry them to the moon or start on other solar system expeditions.

    Solar sails are an excellent idea. Faster designs incorporate a hybrid system with rockets or some other propulsion. Apparently, using the various Lagrange points in the solar system as a type of super-highway appears feasible, decreasing the required fuel and increasing speeds. http://cellar.org/iotd.php?threadid=1895
     
  19. Zarkov Banned Banned

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    >> any designs on the drawing board for an inertial engine Zarkov? anywhere on the net?

    Look up Dean drive... it supposedly worked (marginally) however the principle is sound.

    Problem is all atempts to understand the principle failed... except..

    I will answer question BUT I will not disclose the principle... I am leaving this madhouse
     
  20. talk2farley Registered Senior Member

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    Ok, lets assume these miracle fibers really do work (I'm skeptical... wouldn't the military be eating this stuff up for body armor?). How do you account for the pull of objects climbing the rope? I read some of the higher posts, and one idea that got tossed around was to have a payload come down the rope at the same time as one was climbing up. This would not work, however, as it takes less energy to climb down than it does to climb up, obviously. Gravity is assisting, rather than resisting. You still end up requiring a conventional lift system mounted on the anchor, to counter the downward force, which adds up to longterm operating costs. Why not just use the simple, and cheap laser-lift method?
     
  21. Mr. Chips Banned Banned

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    Here's a site that might give you some answers to your questions. One scientist believes the first one could be operating in 12 years time, with a number in use in 15 years. http://www.unknowncountry.com/news/?id=1410 The report is dated April of 2002. If you dig deeper, you find it stated that the material will be available in five years and a working system inside of a decade.

    edited for spelling
     
  22. talk2farley Registered Senior Member

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    Oh, I see. They use electromagnetic lift. That should cut the counter force down to a marginal fraction of what it would have been otherwise, in the same way magrail tracks reduce friction. Won't be a perfect machine, but much more efficient. Still, you are going to have to reorbit the anchor at some point, as the pull forces cannot be eliminated.

    It would be interesting, no doubt. I would love to see such a device erected in my lifetime. NASA could recoup its losses selling advertising space on the cars themselves, perhaps.
     
  23. Dunnoyet Registered Senior Member

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    Many have said that it takes a lot of energy to get into orbit. I was wondering exactly how much, and did some of the math. I didn't get the kinetic energy for orbit, but, assuming a one-ton item, you go from 2372 J in kinetic energy on the ground to 2,512,549,691 J in potential energy in orbit (assuming that gravity is, indeed, 98% of itself). You also have more kinetic energy in orbit, since you have to get into freefall. Even if you go up in one day, that's 104,689,471.625 joules per hour.

    Here are my assumpitions:
    mass = 1 ton, or 1016 Kg
    LEO is about 160 mi., or 257,495 m
    acceleration due to gravity at 160 mi. up is 98% of earth surface normal

    I think that the sun is the best bet for that kind of energy, but we need a way to tap it.

    edit: I just used a conversion program to find out that the 2.5 billion joules is roughly 698 kilowatt-hours.

    yet another edit: See the next page for better numbers!
     
    Last edited: Jun 17, 2004

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