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Forget Mars. Should We Go To The Moon?
me98411 writes "We have discussed earlier about the President's Commission on Moon, Mars and Beyond and about how a direct trip to Mars is the way to go (or way not to). In a BBC article, the division in the astronomers and space geeks community about the use of the Moon as a base to develop ways to travel to Mars is highlighted. Now, Nature is asking: Should we go back to the moon? Is a manned mission to the moon even necessary?"
Yes, going to the moon would be nice and if we mine it for hydrogen-3 it will also be profitable.
I belive that resupplying a Moon base would be as expensive as resupplying a Mars base and could even be more. The main cost is boosting mass out of Earth's gravity well which you have to do in both cases. To land something on the moon you also have to carry propellant to decelerate to rest on the surface. Landing something on Mars you at least have the option of aerobraking, reducing the amount of mass that needs to be sent. For supplies, cost would have little to do with flight times.
You seem to be under the impression that the moon's spin is locked relative to the sun so that the sun never rises or sets. That's not true. The moon is locked relative to its orbit around the Earth. The moon's "day" is approximately one month long: two weeks of sunlight followed by two weeks of darkness.
This would cause big logistical problems and huge temperature swings for a moon base.
And don't forget the 2-week day/night cycle that makes growing plants on the moon impractical.
Good grief. You talk like we're going to plant crops on the lunar surface. They're called greenhouses, and you close the blinds every twelve hours. At night, you flip on the growlights. Sheesh.
You can tell a great deal about the character of a man by observing those who hate him.
Actually, Zubrin has you covered there, too. I probably won't do his plan justice with my summary (after all, he wrote a whole book on it), but off the top of my head, here are several safety factors he described.
First of all, his plan involves sending as much as possible ahead of the manned mission. Beyond the obvious launch of critical supplies, he describes a very cheap system for generating huge amounts of fuel using the Martian atmosphere. On top of that, we'd send the RETURN vehicle to the surface ahead of a manned mission.
That means you know in advance that you have a return vehicle and fuel already waiting for you -- before you even leave.
Second, the most optimal trajectory for a Mars mission automatically results in a "free return trajectory" -- which means if something goes wrong, the ship will automatically slingshot around Mars and return to Earth, without any fuel usage or other manuvering input from the crew whatsoever.
That means the main risks are surviving space itself (radiation, lack of gravity, isolation psychology), landing (this will remain high risk for a long time to come), and living in the relatively harsh Mars environment until the return launch window opens. (I no longer remember the numbers, but that isn't a terribly long wait.) Of those risks, only the last one requires much from a technological development perspective, and we can learn a lot from a very relevant example of survival under similarly extreme conditions: long term nuclear submarine missions.
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