That’s apparently the NASA reaction to the news that a vast undergound ocean of ice has been discovered on Mars. There had been rumors of this last week, for anyone who’s been reading Nasa Watch. I hadn’t pointed it out because a) I’m not that interested in Mars and b) I didn’t think that most people would find it as significant as they apparently do. I’ll explain why in a minute.
Apparently, NASA is going to use this as an excuse to commit to a manned mission to the Red Planet. It will be interesting to see how much this has been coordinated with the Administration and the Hill, and what their response will be. The agency still has little credibility when it comes to managing and estimating either future, or current, costs on major programs like this. I still think that before they’re given carte blanche to go to Mars, they’re going to have to somehow demonstrate that they won’t screw it up.
If they want to make it an international effort (as the State Department will certainly want to do), then they’ll have to wrestle with their past history of such activities. There’s no evidence that making ISS an international effort saved us any money, and quite a bit that it cost us, and slowed down the schedule.
And the Europeans are going to have to think long and hard before signing up to such a joint endeavor, because the US track record in terms of keeping up our end of such agreements is atrocious, including the current brouhaha about how many crew ISS is going to support. The Europeans are rightly complaining that we’ve gone back on our pledge to have at least seven crew available at the station.
Now, as to why I didn’t (and still don’t necessarily) think it’s that big a deal.
One of the reasons that are being stated for its significance is that it will allow much less water to be taken along on the trip, making the flight cheaper. The other is that it dramatically improves the prospects for finding life there.
I’m not a planetary scientist, and I don’t even play one on the Internet, so I’m not going to state an opinion on the latter point, other than that water is a necessary, but not sufficient, condition for Life As We Know It, and while the discovery may improve the prospects for finding it, it doesn’t necessarily make the probability large. And if oceans of water ice are good, oceans of water liquid should be better, but I don’t see any rush by NASA to send out a manned mission to Europa (one of Jupiter’s moons), which has just such an ocean under the ice layer on top.
As to it making the Mars mission easier–yes, it does, but not all that much. A manned Mars mission has many technical hurdles, and the need to carry water is the least of them. In fact, carrying water en route actually helps one of the other problems–what to do in the event of a solar storm. Radiation is a problem in general on such a long-duration deep-space mission, but if the crew were to get caught in a period of intense solar activity, it would kill them before they even reached the planet. The only real solution to the problem is extensive shielding. It turns out that water, in sufficient quantities, does a pretty good job of that, if it is carried in tanks, inside of which the crew can go as a “storm cellar.”
The main benefit of finding water is that it eliminates the need to have to carry the water for the return trip on the outbound trip, which can in turn save tremendously on propellant costs.
It’s also possible that the vehicles could use it as a propellant, by setting up a plant to electrolyze it into hydrogen and oxygen. But Zubrin’s concept already exploits a different, and perhaps better, concept–using methane and oxygen generated from the Martian atmosphere. These propellants have advantages for long missions, because you don’t have as much of a problem with boiloff as you do with the low-temperature liquid hydrogen, for long missions. Use of cryogenic fuel would have penalties of additional refrigeration and insulation, to keep your fuel from boiling away before you reach the destination planet.
To me, as a systems engineer, what this means is that all of the trade studies on how to do manned Mars missions have to be revisited, because one of the primary assumptions on which they’re based–a lack of easily-obtainable water–has just evaporated. So everything we think we know about going to Mars may be wrong.
Finally, I’m concerned that this will become another Apollo, and that in our rush to get to Mars, we will once again neglect the real issue, which is the cost of access to low earth orbit. I hope that there will be some serious discussion to coming up with innovative ways of tackling this fundamental problem, before we design mission concepts that require us to redevelop the Saturn V.
[Thanks to Mike O’Ronain for the heads up]