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Thread: Mars in a decade?...

  1. #661
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    Quote Originally Posted by Hop_David View Post
    So a transfer vehicle for 3 days will cost less than a 8.5 month transfer vehicle.
    And no transfer vehicle at all will cost less than a 3 day transfer vehicle.

    Screw it - lets go and live in caves, they're cheaper than Condos.

  2. #662
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    Quote Originally Posted by Warren Platts View Post
    there is David McKay himself who went into the hornet's nest of the Mars Society and made an eloquent case for doing the Moon first
    I note you singularly fail to answer my questions, yet again. You refuse to answer Jon's questions, you refuse to answer mine. Your accusations regarding this 'anti-lunar' bias are just laughable Warren. Moreover your

    However - if David McKay is making an eloquent case for doing the Moon first - I'd like to see it. I have said - repeatedly - give me sound scientific justification to go back, and for going back with humans, and I would be on board. Is there a video, a paper?

    Right now you're basically saying that he says we need to go to the moon thus you're right, I'm wrong.

    That's not enough I'm afraid. What's his reasoning, what's his justification, what's his plans.

  3. #663
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    Quote Originally Posted by djellison View Post
    I note you singularly fail to answer my questions, yet again. You refuse to answer Jon's questions, you refuse to answer mine. Your accusations regarding this 'anti-lunar' bias are just laughable Warren.
    The anti-Lunar bias at the Decadal Survey and NASA in general has been noted by Dr. Spudis as well on numerous occasions.

    ,
    However - if David McKay is making an eloquent case for doing the Moon first - I'd like to see it. I have said - repeatedly - give me sound scientific justification to go back, and for going back with humans, and I would be on board. Is there a video, a paper?
    Uh, I keep conflating David McKay with Chris McKay; but anyways here's a link to a lecture by Chris McKay, arguably the one-man source of the anti-Lunar bias in the Decadal Survey since the mid-1990's, telling the Mars Society that if we want to send humans to Mars, we are better off starting a permanently-manned Lunar base first. The conniption fit by Zubrin in the audience alone is worth the price of admission!

    Dr Chris McKay on possible steps to human exploration of Mars (uploaded by the Mars Society)

    This is the link to the first portion; you should be able to find the rest.


    Right now you're basically saying that he says we need to go to the moon thus you're right, I'm wrong.

    That's not enough I'm afraid. What's his reasoning, what's his justification, what's his plans.
    Wrong. Me and Hop have made numerous arguments, but reason with you is about as effective at penetration as water off the back of a duck. Since you prefer ad hominem arguments to make your own case (e.g., "many many many" scientists at teh Decadal Survey can't be wrong; if Lunar ISRU were possible every scientist on the planet would be for it), I thought maybe an appeal to authority to one of your favorite Mars scientists might make on impact.

    His reasoning is basically the same as the one we're making here: that the Moon is a whole lot closer than Mars. It's that simple. The scientifc justification is geology. Just what I've said. Yes, he doesn't emphasize ISRU. But I like I said, the ISRU is the icing on the cake.

  4. #664
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    Quote Originally Posted by Warren Platts View Post
    the Moon is a whole lot closer than Mars. .
    And Orlando's even closer than the Moon. Let's just go there. It'd be cheaper and easier.

    Incidentally - Chris McKay's top item - the very opening slide... Point 1. Mars Sample Return. If you want to rip planetary sciences a new one by pulling out $1B/annum, that's never going to happen.

    He is also speaking - at length - about the attractiveness of Mars as a target scientifcally. And he puts NEO's before the Moon.

    He doesn't present any scientific reasoning for going to the Moon. He presents, imho, flawed programmatic reasons for going. Zubrins first point is entirely accurate - programmatically, an NEO isn't actually a big distraction. A lunar base would require a whole bunch of stuff that has nothing to do with going to mars, and the ISRU opportunities are totally different. However, I totally disagree with Zubrin re: MSR. We need to do that as a precursor to a human program. I also strong disagree with Chris when he says we can do both. We can't. We simply can not afford it.

    Also interestingly - he says that if there were bases on both Mars and the Moon.... he wouldn't want to go to the lunar one, he'd rather go to the Mars one.
    Last edited by djellison; 2010-Dec-09 at 05:47 PM.

  5. #665
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    You're missing the point Doug. We're going to Mars. But the best way to do that is through the Moon.

    Did you watch McKay's lecture? What do you think about that?

  6. #666
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    Quote Originally Posted by djellison View Post
    And no transfer vehicle at all will cost less than a 3 day transfer vehicle.

    Screw it - lets go and live in caves, they're cheaper than Condos.
    Caves vs condos?

    More like a Ford Focus vs DeLorean

    One is affordable, does the job and is economic.

    The other isn't affordable, gets horrible gas mileage and is more likely to break down.

    I've given the arguments but they keep getting buried in a growing thread.

    Moon vs Mars
    Both have CHON
    One is 3 day trip, the other 8.5 months.
    One has launch windows each 2 weeks, the other 8.5 months.
    Round trip delta V to the moon is less.
    3 second light lag vs 10 to 50 minute light lag.

    Most importantly is the delta V proximity of lunar propellent to LEO and EML1. Propellent depots would break hops into 4 km/sec (for LEO to EML1) and 2.5 km/sec (from EML1 to moon). If aerobraking and/or Belbruno paths are used, the 4 km/sec between LEO and EML1 could be substantially reduced.

    This enables single stage, reusable vehicles for transportation within cislunar space.

    Jon Clarke has cited the shuttle that reusable vehicles aren't desirable. The round trip delta V of the shuttle is 18 km/sec. 8 km/sec is accomplished via aerobraking. While delta V via aerobraking doesn't have the enormous mass penalty of propellent, it does have a substantial mass penalty, as well as adding complexity and failure modes.

    In contrast, EML1 to moon has a 5 km/sec round trip budget. EML1 to LEO has a 7 to 4 km/sec delta V budget, depending on whether aerobraking is used or Belbruno paths utilized. But even the worst case EML1 to LEO round trip delta V is much, much better than the shuttle's.

    Shorter trip times, more frequent launch windows and the possibility of reusable vehicles makes a lunar base vastly less expensive than a Mars base.

  7. #667
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    Quote Originally Posted by djellison View Post
    And Orlando's even closer than the Moon. Let's just go there. It'd be cheaper and easier.
    Incidentally - Chris McKay's top item - the very opening slide... Point 1. Mars Sample Return. If you want to rip planetary sciences a new one by pulling out $1B/annum, that's never going to happen.
    He is also speaking - at length - about the attractiveness of Mars as a target scientifcally. And he puts NEO's before the Moon.
    He doesn't present any scientific reasoning for going to the Moon. He presents, imho, flawed programmatic reasons for going. Zubrins first point is entirely accurate - programmatically, an NEO isn't actually a big distraction. A lunar base would require a whole bunch of stuff that has nothing to do with going to mars, and the ISRU opportunities are totally different. However, I totally disagree with Zubrin re: MSR. We need to do that as a precursor to a human program. I also strong disagree with Chris when he says we can do both. We can't. We simply can not afford it.
    Also interestingly - he says that if there were bases on both Mars and the Moon.... he wouldn't want to go to the lunar one, he'd rather go to the Mars one.
    Both McKay and Zubrin are very smart guys and I have a high regard for both of them. They both want the same thing, and as I do: manned missions to Mars, soon. They differ on the best way to achieve that. Zubrin is opposed to opening up lunar outposts first but only because he thinks they would be too expensive and would take too long. He's probably right with the way things are now. However, if it can be shown that there are mineable resources on the Moon then that raises the possibility commercial interests could pay for such outposts. That's why I say there should be precursor ground truth missions undertaken and soon to confirm that unexpectedly high, valuable mineral readings from the LCROSS mission.


    Bob Clark

  8. #668
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    Quote Originally Posted by RGClark View Post
    However, if it can be shown that there are mineable resources on the Moon then that raises the possibility commercial interests could pay for such outposts. That's why I say there should be precursor ground truth missions undertaken and soon to confirm that unexpectedly high, valuable mineral readings from the LCROSS mission.


    Bob Clark
    Didn't you read what Doug said? There is very, very little $$$ for supporting the sort of in depth robotic research you say you want. To do it right would take at least $1B/year from now until 2030. The HSF program is strapped to the limit as it is. It can't afford $1B off the top to support more robotic research. It's a job best suited for humans anyway. So we should plan on sending humans up there by 2020, and allowing them to do what humans do best: exploration.

  9. #669
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    Quote Originally Posted by Warren Platts View Post
    Didn't you read what Doug said? There is very, very little $$$ for supporting the sort of in depth robotic research you say you want. To do it right would take at least $1B/year from now until 2030. The HSF program is strapped to the limit as it is. It can't afford $1B off the top to support more robotic research. It's a job best suited for humans anyway. So we should plan on sending humans up there by 2020, and allowing them to do what humans do best: exploration.
    Warren, I don't believe you really believe that. The LCROSS mission showed it is possible to do low cost precursor missions. One small, simple lander placed in the LCROSS crater site could confirm the numbers returned by LCROSS. After that, mining companies would be chomping at the bit to pay for more detailed in situ surveys - with the promise they could exploit the resources there.
    A big part of the LCROSS teams ability to save cost was not having to pay for the launch since it piggy backed on a mission already paid for. I had a discussion on this score on another forum about the Google Lunar X-Prize entrants possibly saving on launch costs by piggy backing on some commercial launches. The objection was made, legitimately, that the commercial satellite operators would not want to risk their multimillion dollar satellites on attached propellant filled spacecraft built by amateurs.
    However, if the piggybacked spacecraft was built by NASA with decades of experience behind them then they could be assured of its reliability and at least some of the launch cost could be paid for by NASA.


    Bob Clark

  10. #670
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    Comment on Lunar mining moved to Gold Mining on the Moon thread.

  11. #671
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    Quote Originally Posted by JonClarke View Post
    Then coime up with a simple efficient archiecture that does not use an HLV
    You dropped a few words from what I said. Ares V HLV is NOT the same as HLV

    In another conversation you've asked me:

    Where is the Mars mission architecture using depots and no HLVs?
    Where have I suggested such an architecture exists?

    Warren has suggested a lunar assisted Mars architecture that uses 70 tonne to LEO HLVs.

    Here is one of his quotes from Mars Indirect:

    Quote Originally Posted by Warren Platts View Post
    It is a myth that the ULA affordable architecture paper is an argument against heavy lift: although it shows that an aggressive BLEO program can be done it 30 ton chunks, it also says that reasonably sized HLV's would "amplify" their proposed architecture (e.g., they just put out a 2010 paper arguing that ULA could develop a 70 ton HLV for about $3B USD).
    I believe lunar assisted Mars architecture would need a 70 tonne to LEO HLV.

    While I decry Ares V (188 tonne to LEO) and the current 130 tonne to LEO pork frenzy, I don't recall suggesting an HLV free Mars architecture.

    Please tell me who has suggested such an architecture?

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