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I am unclear why a vehicle that can lift 45 metric tons would be sufficient for the moon and insufficient for mars. It takes more delta V to for from earth to the moon, then it does from earth to Mars.
The reason for this is because you can potentially aerocapture into Mars orbit, saving yourself the propulsive delta-V it would otherwise take for Mars orbit capture.
The total delta-V is higher for a trip to Mars, it's just that you don't need to burn fuel to make up the entire delta-V budget. At this point I'm reluctant to trust aerocapture, as it's never been tried before. If unmanned probes can successfully demonstrate it, I'd be more than happy to consider it for a manned Mars flight.
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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quote from GCNRevenger:
The big difference between Moon and Mars is primarily that it takes much longer to get there. To get to the Moon, stuffing the crew in a capsule the size of your bathroom for a few days isn't an issue, but for a six-month coast to Mars, you would obviously need more room, coming and going. You would also need much more in the way of supplies, life support, and radiation shielding.
Cev as we know it now is only 20Mt and is targeted for only 16 days for a crew of approximate 4 perhaps for lunar missions.
This said what size or mass is the habitat combo lander for Mars in comparison to one need for the moon for say a simulated 9 months mission be?
We should design the moon stuff with the goal of it being used for Mars timelines.
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ROCKET SCIENTIST Michael D. Griffin's return to NASA, this time as its top administrator, seems assured. But that's the last guaranteed win the current head of the space department at Johns Hopkins' Applied Physics Lab can count on for a while.
While he is on record backing the Bush plan to send humans as far away as Mars, we hope his reputed reasoned skepticism and grasp of the big picture also lead him to back the mission to repair the Hubble Space Telescope.
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By the way, Zubrin's *Case for Mars* has several very positive comments about Mike Griffin, who helped spread the gospel of Mars Direct around NASA in the early 1990s. You can find the references by checking the book's index.
-- RobS
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I sure hope he doesn't get suckerd into going up to Hubble again...
Why does everyone keep on calling the Hubble servicing mission a "repair?" It isn't a repair, its a servicing, because Hubble was designed to require regular servicing. Just like changing the oil filter on your car, that isn't a repair... And so, since the Hubble-Huggers will come out and whine and moan and whip themselves the NEXT time Hubble needs fixing again, because they are basing their position on sentimentality. Where does it end? When is "just one more!" one too many?
Answer: When the cost exceeds the bennefits. At the moment, the cost of fixing Hubble rather then replacing it is has a much higher cost and risk per the returns yeilded on such a large and somewhat dangerous investment.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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At this point, even Homer Hickam (of "Rocket Boys" / "October Sky" fame) is advocating a quick end to the shuttle program and a new emphasis on going back to the moon. Presumably this means he opposes a Hubble servicing mission too.
The irony is that in the immediate aftermath of Columbia's loss, Hickam believed the shuttle should be flown until ISS was completed, then replaced with OSP.
Michael Griffin will undoubtedly feel a lot of pressure from various sectors to restore Hubble SM4. He's new to the job and Hubble's supporters think they can mold him like a lump of clay. At the same time, the White House budget office can overrule an SM4 restoration by denying NASA the funds for the mission. It will be interesting to see how this plays out, but unless Griffin restores a robotic servicing mission, Hubble is toast.
(Personally, I'd like to see a robot fix Hubble's gyros and batteries, if only to push the state-of-the-art in robotics. Any new Hubble instruments should have to wait for the Hubble Origins Probe.)
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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A robotic mission to service HST isn't in the cards. There is no possible way it would cost less then about a billion dollars, and it is very unlikly that it would be ready, and have a reasonably high chance of sucess, by the time Hubble's batteries or gyros die.
Making a robot to just give Hubble a little nudge out of orbit is much easier then building a huge robot with enough fuel to raise its orbit from a propellant prespective, which makes the whole mission much smaller and cheaper.
A parasitic robot that carries a surrogate set of gyros & power systems is probobly not practical either, as this would require the robot to perform rewiring, and that there is no attach point on the rear of Hubble that is structurally sound.
And don't forget... Hubble's other systems (many of which are hard/impossible to replace on orbit) might simply die from old age pretty soon.
Its either the Shuttle, and soon, or not at all... I hope that the Congress/White House doesn't have to kick the legs out from under Michael's tenure by telling him not to do stupid things.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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