Re: Nova's Astrospies



Jeff Findley wrote:
"Pat Flannery" <flanner@xxxxxxxxxx> wrote in message news:13rn2mntatjsvb3@xxxxxxxxxxxxxxxxxxxxx
Jeff Findley wrote:
The rovers are great at identifying interesting samples, but they're *not* great at reproducing all of the equipment you'd have in an earth bound laboratory. They have a few hand picked instruments on board, and that's all they're ever able to work with.

That's the trade-off for the low mission cost.
With unlimited amounts of money you could land manned expeditions all over Mars; but we don't have unlimited amounts of money.

Of course not. But what would it take to recreate a well equipped scientific lab on Mars and make it automated? The answer is likely a whole hell of a lot more than sending a manned expedition there to bring back samples to labs on Earth.

Such a lab could be powered by a nuclear reactor, but unfortunately, the people will need food and water also.
in a automated lab, only the samples need be returned to Earth (and not much of each sample either; quite small carefully selected pieces of several hundred samples would do just fine. Total sample weight may only be around 100 pounds.) on a manned expedition the samples _and crew_ need to be returned, with all that implies for weight and supplies for the return trip.
Then there's the reentry aspect. for the samples the return capsule can just slam into the atmosphere at full tilt because the samples can take the G's... but a human crew is going to have to be slowed down gradually before landing, which complicates the design of the capsule and the reentry profile chosen.

I don't believe that unmanned landers will ever be able to replicate the capabilities of a manned mission.

As I pointed out, cost is one main argument for the unmanned route.
putting a manned expedition on the surface would allow you to study one area in great detail, but for the weight you could probably study at least ten areas to less detail with sophisticated unmanned labs, due to the savings in consumables on the way out and back and the fact that only the samples need be returned to Earth, leaving the labs in place on Mars.
Although the surface of Mars is nowhere near as variable ass Earth due to its lack of seas and large scale flora and fauna, it still would be interesting to get data on several sites - the volcanoes, the Valles Marineris, the Hellas Basin, and both poles for starters.
Building, launching and operating the rovers for their first year cost around 425 million dollars. That's less than the cost of one Shuttle mission, and I'd say we certainly got our money's worth.

Certainly we did, but it's not a replacement (in terms of capability and science returned) for a manned mission.

Remember though; that's a manned space shuttle mission into LEO for around a week or two.
Sending seven people to Mars for a around a total mission time of three years is going to cost a couple of orders of magnitude more than that by the time R&D is finished and a ship built in orbit.
NASA has proposed manned Mars missions for around forty years now, and Congress takes one look at the price tag and craps their pants.
So it could come down to unmanned missions or no mission at all, and in that case the unmanned missions are certainly the better alternative.
Barack Obama in particular is saying the Constellation program isn't worth it, and unmanned is the way to go:
http://www.chron.com/disp/story.mpl/front/5546810.html
(John McCain on the other hand says we may have to forgo men on the Moon for H-bombs on Tehran, and Hillary says that both Obama and McCain are big poops for not realizing what a genius she is.)

to planetary science. Manned and unmanned missions compliment each other.

Remember the Moon; first came the unmanned probes, then the manned landings, then the miniseries and movies...as, let's face it, the Moon is a damned boring place.

Due to the constraints of the needed sunlight for power and thick enough atmosphere to slow the lander down, only about 5% of the total Martian surface can be explored by the present rover design, but I would have been in favor of building more of them, considering how well they've worked.

NASA is too into one-off missions. Every unmanned mission seems to be unique, with a few exceptions where multiple spacecraft of the same design were built.

That's why I am in favor of sending some more MER-derived spacecraft up there...because we now know that we have a exceptionally good design for a small lander that can ride on a Delta II, and that makes it proven and economical.
The two things that they really should do, both of which would be highly economical, would be.
1.) Put a high powered optical microscope on the surface, and examine soil samples with it. If there is now or ever was life there, it should show up in microfossils in the soil; things like spores or the skeletons of marine creatures like diatoms.
2.) Put something down on one of the polar caps that scoops up some of the ice, melts it, checks its composition and has a look at it under a microscope also. I am only going to be fully convinced that those polar caps contain water ice when they show a sample of liquid water from inside of the lander.
Again, if there's life, some things should be in that ice that were carried there by the wind and became frozen.
MPL was supposed to do things along these lines, but it's been nine years since that mission, and such a comparatively simple mission hasn't been replicated (hell, the lander could be something simpler than the MER landers and use battery power in the few hours it would take to do this.)
I think that in their heart-of-hearts, NASA thinks that the place is now, and may always have been, devoid of life...and they avoid doing fairly simple experiments like these to keep the possibility of life open so as to get more funding for further missions....because a lifeless Mars is not much better than a lifeless Moon as far as funding goes.

Pat

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