A Return to the Moon by the Apollo 11 50th Anniversary.

Discussion in 'General Science & Technology' started by Exoscientist, Nov 2, 2012.

  1. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    NASA administrator Charles Bolden told the NRC committee on human spaceflight that an asteroid mission didn't necessarily have to be a far trip:

    Bolden: Don't Have to Travel Far to Asteroid to Meet President's Goal.
    Marcia S. Smith
    Posted: 19-Dect-2012
    http://www.spacepolicyonline.com/ne...ravel-far-to-asteroid-to-meet-presidents-goal

    Perhaps he was referring to the Planetary Resources, Inc. proposal to bring a small asteroid to lunar orbit. But another possibility is a mission to near Earth asteroids that can be accomplished in about a month round trip travel time. See the table of NEO's here:

    Near-Earth Object Human Space Flight Accessible Targets Study (NHATS).
    http://neo.jpl.nasa.gov/cgi-bin/nhats

    Select max delta-v <= 12 km/s, visit time => 8 days, unlimited visual magnitude, the H parameter, and unlimited orbital uncertainty, the OCC parameter. Then there are several asteroids at 26, 34, and 42 day travel times, including stay times at or above 8 days. If you subtract off that stay time to make it only a day or so then the round trip travel time will be in the range of a month or so.

    This could serve as an intermediate step for BEO missions between the Apollo missions at max. 12 days and a Mars mission at 6 months one-way travel time.

    Bob Clark
     
    Last edited: Dec 22, 2012
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. river

    Messages:
    9,793
    Knowledge
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. youreyes amorphous ocean Valued Senior Member

    Messages:
    2,826
    So is shooting oneself with heroin. If a space project is too risky to outweigh the political, resource, or social benefits than it isn't worth endulging in, not all knowledge of the universe needs to be unwrapped.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    SLS for Return to the Moon by the 50th Anniversary of Apollo 11, page 2: Orion + SEV design.
    http://exoscientist.blogspot.com/2012/12/sls-for-return-to-moon-by-50th.html

    Argues the first version of the SLS will have a 95+ mT payload capacity, not just 70 mT, enough to do a manned lunar landing by its first launch in 2017. And moreover addition of a small propulsive stage a fraction of the size of the upper stage on an EELV can raise the payload to 130 mT at minimal additional cost.


    Bob Clark
     
  8. river

    Messages:
    9,793



    What is too risky about going back to the moon ? Politically , resource or socially ?

    Explain each risk
     
  9. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    A recent report suggests using the hydrogen tank of an upper stage for the SLS as a space station:

    Skylab II: A NASA 'Back to the Future' Concept to Open Up Space Exploration
    By Mark Whittington | Yahoo! Contributor Network – Fri, Dec 21, 2012
    http://news.yahoo.com/skylab-ii-nasa-back-future-concept-open-space-170200842.html

    Note there had been suggestions before of using the space shuttle external tank(ET) as a space station:

    The Space Island Project
    http://www.youtube.com/watch?v=sYIo-0qo9FA

    STS External Tank Station
    www.astronautix.com/craft/stsation.htm

    The External Tank Torus.
    A Technical Review by David Buth
    http://freemars.org/studies/torus/ettoru2.html

    Using the External Tank From the Space Shuttle as a Space Station ...
    aeromaster.tripod.com/grp.htm

    At an empty tank mass of 26.5 metric tons(mT) this would be well within the
    capability of the 70 mT SLS of getting this to LEO, as at least an outer hull
    of a space station. Note for this purpose we could remove the ET bulkheads so
    it would even weigh less than this.
    This would have two and a half times the volume of the ISS.
    And at the 130 mT payload capacity of the later SLS version, using Centaur
    style in-space stages we could even transport this to the Moon.


    Bob Clark
     
    Last edited: Jan 8, 2013
  10. leopold Valued Senior Member

    Messages:
    17,455
    the biggest advantage of a moonbase would be as a jumping off base.
    this can provide for lighter vehicles and shorter transit times.
    who knows, we might even stumble across some strange chemical reaction that only occurs in microgravity.
     
  11. Exoscientist Mathematician Registered Senior Member

    Messages:
    139

    Interesting articles:

    NASA MSFC Says That SLS Performance Specs Fall Under ITAR.
    http://spaceref.com/news/viewnews.html?id=1697

    Report: NASA in Huntsville won't release performance specifications for new rocket.
    By Lee Roop | lroop@al.com
    on January 25, 2013 at 3:23 PM, updated January 25, 2013 at 3:51 PM
    blog.al.com/breaking/2013/01/report_nasa_in_huntsville_wont.html

    Rand Simberg suggested to me the reason why NASA keeps saying the Block 1 version of the SLS will only have a payload of 70 mT, same as for the Block 0, is to maintain the pork of the expensive upper stage.

    Citing ITAR for the current Block 1 version makes no sense since they were willing to give the 70 mT capability of the Block 0. Also, another conclusion you can draw from this is the payload capability of the Block 1 will not really just be 70 mT otherwise they would have just given this number again for the FOIA request.

    My guess about why NASA kept giving the 70 mT number of the Block 0 and not the real number of the Block 1 was because they just didn't take the time and effort to do the analysis on the capability of the upgraded rocket. It was easier to just cite 70 mT because they knew the new version would at least reach this. But now I'm beginning to think perhaps Simberg was right.

    Certainly the cite of the ITAR restrictions just raises more questions.

    Bob Clark
     
  12. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    I've been informed by knowledgeable individuals that the Block I SLS likely will have greater payload than just 70 mT, though not as high as what I was estimating. The problem is with designing any new rocket there is always weight growth so you put some error bars around your mass estimates. NASA frequently takes a conservative approach to those mass growth estimates which can drive down your payload estimates. In any case I don't believe there was anything untoward in the decision not to release the SLS specifications. I think as the SLS comes closer to completion, hopefully by 2017, more accurate numbers for its capabilities will be released.
    However, it should be noted that many industry insiders do not believe the final Block II version of the SLS will ever fly, because of its long time lag, 20 years, and high cost. Then I think it would be prudent for NASA to investigate weight saving techniques on the Block I SLS core to maximize its payload capability. Then even if the Block II is never completed we can still perform BEO missions even with just the Block I scheduled to launch in 2017.
    Some suggestions for lightweighting the SLS core discussed here:

    SLS for Return to the Moon by the 50th Anniversary of Apollo 11, page 3: lightweighting the SLS core. http://exoscientist.blogspot.com/2013/02/sls-for-return-to-moon-by-50th.html


    Bob Clark
     
  13. KitemanSA Registered Senior Member

    Messages:
    624
    Let NASA fade away. Perhaps Elon Musk will drop by the moon on his way to settle Mars!

    Please Register or Log in to view the hidden image!

     
  14. youreyes amorphous ocean Valued Senior Member

    Messages:
    2,826
    Oh please Space X is barely starting and its success lays in LEO.
     
  15. Gravage Registered Senior Member

    Messages:
    1,241
    Finally the light at the end of tunnel.
     
  16. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    A manned lunar landing flight for less than $100 million in launch cost, assuming the Falcon Heavy really does hit the $1,000 per pound price point:

    Budget Moon flights.
    http://exoscientist.blogspot.com/2013/03/budget-moon-flights.html

    Notably it uses European stages for the translunar injection and lander stages. Then you could have an all European mission if using an Ariane 5 ME and a separate human-rated European launcher for crew instead of a Falcon Heavy.
    As I discussed before, a European human-rated launcher is doable by just selecting for the Ariane 6 the all-liquid fueled version. This could also be ready by the same 2017-2018 time frame for the Ariane 5 ME.
    This is another advantage of the liquid-fueled version of the Ariane 6. It could also allow low cost European manned lunar flights around the same time as the Americans.


    Bob Clark
     
  17. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    On another forum it was mentioned Dave Masten of Masten Space Systems in a SpaceVidcast video discussed adapting a Centaur upper stage to serve as a lunar lander. In the video he estimates it to cost in the range of only $50 million(!)

    The discussion on the lunar lander takes place about 15 minutes into the one hour video. Masten also mentions this modified Centaur could transport 6 metric tons between a Lagrange point, L1 or L2, and the lunar surface. Such a lander could also be used between low lunar orbit and the lunar surface, as for a manned mission from Earth:

    A (mostly) commercial architecture for solar system exploration - YouTube
    [video=youtube;OzlJd3Pbpxg]http://www.youtube.com/watch?v=OzlJd3Pbpxg[/video]

    If true, then it is unconscionable that NASA claims a return to the Moon can’t be done because a lander would cost ca. $10 billion, when it can actually be done two orders of magnitude more cheaply than that. In any case NASA needs to do a study to see if this conversion of a Centaur to a lander can actually be done so cheaply.

    Bob Clark
     
  18. billvon Valued Senior Member

    Messages:
    12,810
    Yes, a lot of people claim a lot of things. Spacecraft often turn out to be more expensive than people predict. In this case it is unlikely that a spacecraft that can support a human crew and get them reliably to the surface of the Moon and back to the Earth would cost less than a nice mass-produced business jet.
    In such cases it might be better to believe the people who have actually built one.
     
  19. Exoscientist Mathematician Registered Senior Member

    Messages:
    139
    The individual cost of a business jet could well be less than $50 million. Keep in mind Masten has knowledge of vertical takeoff and landing vehicles from winning the $1 million NASA Lunar Lander Challenge. He is also working in partnership with NASA to design an autonomous robotic lander for the Moon. Masten is actually developing a Centaur-based lunar lander test vehicle since United Launch Alliance(ULA) donated to Masten Space Systems a surplus Centaur.

    See this video about 30 minutes in for more on the Masten Centaur-based lunar lander:

    [video=youtube;oQ4lLTblx5M]http://www.youtube.com/watch?v=oQ4lLTblx5M[/video]


    Bob Clark
     

Share This Page