about the universe forum commander Shop Now Commanders Circle
Product List FAQs home Links Contact Us

Thursday, February 19, 2015


Steve Cole evaluates:

For most of my life, doing a little math indicated that during my last few years I would get to watch the first manned Mars landing on television. I'm no longer so sure. Given my age and health, I have 3d6 years to go, and I don't see us making it.
1. The estimated date for a landing has constantly slid later and later. I figure the estimated landing date is about as far away now as it was in 1969 when we watched the moon landing on television. At that time it was estimated as 1989.
2. We've basically made zero progress for six years toward building the systems to do the job, with no real likelihood of any serious progress anytime soon.
3. The thing is, we still have no idea how to actually land people on Mars. Rovers, sure, but they only weigh a ton or two. Six people, space to live, air to breath, food to eat, and other supplies to stay for months or
years -- nobody knows how to land that much stuff. The atmosphere of Mars is so thin that parachutes won't do much for a vehicle that big. Retro-rockets -- ok, those will do it, but they add so much weight to what leaves Earth that it just doesn't seem plausible. Then again, maybe. We're pretty much to the point that we have to launch several rockets then link up somewhere (in orbit, in lunar orbit, in Mars orbit, on the surface of Mars) so maybe we just add another rocket launch just to carry the fuel for our landing system. What's another few dozen billion dollars?

4. Everybody knows we get a launch window to send something to Mars every two years. But the really best windows, the kind you probably need for something as big as a habitat spacecraft, come along every 14 years. The next one is in 2018 (NASA can't do that, maybe some private company could but I doubt it) and after that 2032. To be alive in 2032 I have to live longer than my parents and frankly I'm in a lot worse state of health than they were.
5. Radiation is going to be a deal breaker. A Mars astronaut will (each year) get radiation during flight equal to 10 times the annual limit for workers in a nuclear power plant. Radiation on the surface is still seven times the limit as that thin atmosphere doesn't help much and there is no magnetic field. Radiation shielding is very heavy and the cost of this trip is based largely on the weight. So add another rocket launch (and a few billion) to carry up to orbit the radiation shields for the capsule, or invent some new kind of electromagnetic shielding. Oh, then you have to land a much heavier capsule with more radiation shielding, and some kind of Mars minivan with more radiation shielding. Did I mention that we still have no practical idea how to land
something that heavy?
6. We have yet to keep a spacecraft flying that long without bringing up spare parts. The International Space Station gets a cargo ship every few months with the parts needed to keep it running. Even more fun, once we got the International Space Station up there, we found out we didn't know as much as we thought we did about how things work in space. The International Space Station is a Rube Goldberg jury-rigged mess of wiring and plumbing and ducting that was not in the original design. Does anybody want to take a newly designed rocket ship to places you can't get spare parts and only then find out if there was something you didn't know about how things work in space more than 200 miles from Earth? We probably need a three-month pre-Mars mission (just loop out and back to nowhere) to test the design. What's a few more years and another hundred billion?
7. The human body doesn't really seem that well designed for space. Sure, we've kept a few guys up in orbit for a year or more, but we've also seen some pretty bizarre things happen to their bodies. They start (slowly) going blind, their muscles atrophy more than exercise can rebuild, and all kinds of other things start breaking down. We now think we can send people on multi-year missions (or one-way permanent colony missions) without anything more than informed guesswork about whether their bodies will function that long.
8. This accomplishment is going to cost a trillion dollars (probably two) with no cash return for the investment. (There is nothing on Mars worth bringing back. Even sample rocks for sale could not be done on a scale that pays for the trip, or any significant part of the trip.) Frankly, I think the taxpayers are tired of donating money for such projects. (Note that we never went back to the moon for the permanent colony that everybody in 1969 said would be operational by 1989.) This assumes that somehow our government suddenly starts to function on something other than wishful thinking as a budget model.