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Glenn Urges Direct-to-Mars Trip

Posted by michael on from the one-way-ticket dept.

Geno Z Heinlein writes "Reuters reports that astronaut John Glenn testified March 4 before the President's Commission on Moon, Mars and Beyond, saying that Bush's plan 'pulls the rug out from under our scientists' and that 'It just seems to me the direct-to-Mars [route] is the way to go.' Referring to the Moon as an 'enormously complex' Cape Canaveral, Glenn said that NASA might spend all the money getting to the Moon and never get to Mars."

3 of 685 comments (clear)

  1. Re:How about telling the truth, Glenn? by prgrmr · · Score: 5, Informative

    The ISS budget is not 2.5 million, but 2.5 BILLION!

    Glenn wasn't talking about the complete ISS budget, just the science portion that's projected to be cut.

  2. Zubrin's Mars Society seems to be doing well ... by torpor · · Score: 5, Informative

    I remember, a few years ago (5?) that the various Mars programs being fronted by the U.S. government were in direct opposition to the way Zubrin and his Mars Society were proposing we do it - with the "Mars Direct Program".

    Now, it seems that there are a significant number of Washington players who are getting behind the scientific thinking that Zubrin's program has produced for us ... and thats good news.

    When I think about where we are currently at, evaluating the Mars situation, and where we've come as a result of an independent organization, it warms my heart. The Mars Society have done a lot to get humans thinking about going to Mars properly, and finally it seems like their momentum is having a great effect.

    --
    ; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
  3. It's harder to get to the Moon than Mars by SB9876 · · Score: 5, Informative

    OK,
    I keep hearing this idea of using the moon as a refueling station. If you haven't looked at the numbers, t seems like a good idea. However, a quick look at the actual orbital mechanics shows that the Moon is a big waste of time. Here's the breakdown for ow much Delta V is needed to get to the Moon and Mars:

    Moon.........Mars
    LEO to Moon/Mars..3.2.........4.0
    Orbital Insertion.......0.9.........0.1
    Orbit to Surface.......1.9.........0.4
    Total.............. ......6.0.........4.5

    Yes, it actually takes LESS fuel to get to Mars primarily because it has an atmosphere you can use to aerobrake. The Moon has no atmosphere and so you have to carry fuel to bleed off your transorbital speed. Furthermore, Landing on Mars is assited by being able to use the aerobrake to bleed off speed on the way down unlike the Moon. Those figures even assume that you don't use a parachute and rely upon retrorockets to come to a stop.

    OK, what about the idea of the Lunar refuelling station? You now lose the 1.9km/s of energy you need to get back off the lunar surface. (you still pay for it but the refuelling barge now pays that cost) The problem is that the cost of getting to the Moon and in and out of Lunar orbit is as expensive as getting to Mars to begin with. Sure, you now havea refuelled ship that can go to Mars from lunar orbit which is cheap BUT you just spent as much fuel getting to the Moon as it would have taken to go to Mars without stopping!

    To use an analogy, I want to drive to New York from Seattle. Now, would it a be a good idea to send a bunch of my friends out to Washington DC to build a gas station for me so that I can drive there, gas up and then drive up to New York? NO! The only way it would make sense is if we were building a spaceship in lunar orbit which is simply insane - we can't even do that in LEO right now. Hell, we have enough trouble doing it on the ground right now.

    Furthermore, as the other respondant mentioned, you can't make fuel on the Moon. All rockets that aren't ion drives (which have no need to refuel at the Moon anyways) need an oxidizer and fuel. There's plenty of O2 on the moon in the form of metal oxides. The Moon's something like 70% oxygen. There's plenty of metal and O2 if we want to expend the energy to get it. However, O2 is the oxidizer - we still need the fuel. All our fuels use (to my knowledge) carbon, nitrogen or hydrogen. That includes everything from gasoline and candle wax to hydrazine and liquid H2. The moon has no large supplies of H2, C or N. You'll have to haul all of those in anyways. It really makes no sense to refuel there.

    There's plenty of good reasons to go to the Moon, refuelling on the way to Mars is NOT one of them.