[meteorite-list] Returning To Sample Mars
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Sep 4 23:13:03 2006
Returning To Sample Mars
September 5, 2006
Washington DC (SPX) - At the recent Viking thirtieth anniversary
celebration, Noel Hinners championed what could be the next great
challenge for planetary science: a Mars Sample Return mission. Hinners
pointed out that, like Viking, Mars Sample Return will prove to be
extremely difficult but immeasurably rewarding.
For a Mars Sample Return mission, a rover would collect samples of
rocks, soils, and the atmosphere, and then a rocket would blast off the
surface of Mars and carry the samples to Earth for detailed analysis.
While some people are opposed to bringing samples of Mars to Earth, the
truth is that martian rocks are already here. To date, 34 martian
meteorites have been collected from various sites all over the world.
These rocks traveled to Earth after having been blasted off the surface
of Mars by a comet or asteroid impact.
Even though scientists can study these meteorites to learn more about
Mars, the rocks have been altered because they went through a lot to get
here -- the explosion that first sent them flying off the martian
surface, the cold, radiation, and vacuum of space, and then the fiery
descent through Earth's atmosphere.
As Hinners explains in this edited transcript, a Mars Sample Return
mission could provide generations of researchers with a variety of more
pristine and scientifically interesting samples to study.
"One of the big challenges facing NASA today is Mars Sample Return. Mars
Sample Return has been on the agenda for a long time, well before the
late 60s, even before the Viking orbiter and lander. Like Viking, Mars
Sample Return is a daunting technological and engineering challenge with
an incredible scientific payoff. So what did we learn from Viking that
might help us figure out how, within our lifetimes, to do Mars Sample
Viking was viewed as incredibly challenging and complex, both for the
technical and the science aspects. Looking for life is not an easy thing
to do. There are many arguments about how to detect life when you don't
know what that life is like. You have so many assumptions and analogies
with terrestrial life as we know it.
Before Viking, the martian atmosphere was poorly known, the surface was
poorly known, and the surface environment was poorly known. Some people
viewed this whole endeavor as verging on insanity.
One effect of the probable Viking detection of "no life", if you call
that a detection, was that it slowed down the exploration of Mars for
several decades. Soon after Viking, I went to the Soviet Union, which
also had a very vigorous Mars program, and I asked them about their next
Mars missions. They said, "There aren't any." I asked why not, and they
said, "You've killed them off. You didn't find life." So this quest for
life has an incredible influence in the Mars program. Now there's been a
revival of the potential for life on Mars, with the recent MER findings
of the ancient presence of pervasive water.
The science imperative for Mars Sample Return is equally compelling to
what Viking was looking for, and in many ways associated with some of
the same goals related to life.
Impediments to doing Mars Sample Return have been technical and, in
large part, budgetary. There's a lot of critical science that simply can
not be done in situ. We're getting much better with our instrumentation
to send to Mars, but we still cannot do certain things. The MER mission
discovered what are called blueberries, these little round ball
bearing-sized, millimeter-sized things. It would be wonderful to have
those back here, in blueberry crumb cake. To dissect them, to see the
layering in them, to do the isotopic study as a function of depth to
understand the history of the water interaction with these materials, to
look at the mineral phases and understand how they formed.
For something like the Mars meteorite ALH 84001, it can be looked at on
the atomic scale here. You simply cannot manipulate and do the analysis
on samples remotely with any of today's technology, or with anything we
can see coming down in the near future. In the Stardust grains that came
back recently, a zircon was found. This was at the micron scale, showing
a high temperature mineral which isn't supposed to exist in comets.
Remote sensing had never shown this before, and it has changed the way
we think about where comets are coming from. What part of the origin of
the solar system do they relate to? Is this a remnant of some previous
generation of a star which exploded and ejected material into the solar
system during its formation? More recently, in another Mars meteorite,
there are little channels that it's very tempting to think may be what
are called DNA tunnels. Probably not likely, but nevertheless it's at
this scale where we see what is really going on.
Essential to Mars human exploration is understanding the chemically
active material. Dust is always a problem. Unless you have inorganic
lungs, I would not want to breathe Mars surface material. But if we get
material back here, we could alleviate health and safety issues by
figuring out what are the essential problems with the dust-sized
particles on Mars.
When we have a human mission to Mars, we've got to know what it is we
want to do for that kind of investment. Much of what they do there will
be science. The science goals can be better defined when we know and
understand what they're going to deal with when they get there.
We also need to show a sense of direction to the public. The public in
large part does not comprehend why we are going to the moon and not to
Mars. So I suggest that having some focus of our human program directed
towards Mars at this stage would help to bridge that, and relate to why
we're doing some things on the moon first to prepare for this eventual
expedition, and maybe long-term colonization of Mars.
Samples are forever. We're still analyzing Apollo samples thirty years
later. There are new techniques that did not exist when Apollo flew. So
as instrumentation develops, you apply it to samples you've brought
back. The Soviet LUNA missions brought back moon samples robotically in
the early 1970s. The Soviets came close to scooping Apollo, in a sense.
They had a sample return mission going to the moon at the same time as
Apollo 11, but it failed. Politically that was good for us, although we
don't like to see anybody fail in missions.
Competition played a role at the time of the Viking program. Prior to
Viking, there were only four successes out of the six U.S. Mars
missions: Mariner 4, 6, 7 and 9. Part of the support for Viking which
made it "affordable" and sustainable was that we were in the space race
with the Soviet Union, which had a vigorous Mars program. Today, we
don't have that competition, although some people are trying to drum up
the Chinese as a competitor to worry about today.
But I think we are now in an era of cooperation. We should cooperate on
Mars Sample Return -- it will cost a lot to do it, so if we could bring
in partners who could shoulder a significant part of the science and
technology engineering and budget, that helps us get this mission into
the U.S. space science budget. It also could provide a model for
international cooperation. We have failed gloriously with our
cooperation on shuttle and Space Station. We have tended to design a
mission, find out that we can't afford it, and then go hat in hand to
our friends and say, "Please come help us; we'd really like you to join
us." There's nothing wrong with wanting their money, but let's bring
them in early.
The European Space Agency is very interested in Mars Sample Return. In
fact, their Aurora human spaceflight program has Mars Sample Return as a
key component. It's only in a study phase at this point, but the
interest is there, so the potential for having them as a partner is
there, along with other countries. Other countries are showing that they
can now accomplish many things which we used to think only we could do.
ESA has Mars Express, and the Japanese recently did land on an asteroid.
Although they had some problems, we think maybe they're bringing samples
back. The capability is all over the world now. I say, let's bring them
in early during the conceptual stage, and make them true partners.
The Viking heritage story is telling. In all the systems and subsystems,
there was mostly new technology. Some technology existed but wasn't
used, like solar arrays, because we didn't think solar arrays would
survive the dust problem on Mars. So instead we used RTGs that had to be
adapted for the Mars environment. All the new technology, for the most
The lesson learned is that new technology is not something to be afraid
of; new technology is to be embraced. You test the bejeebers out of it,
and do everything you can to understand it. One of the most frightening
things in our business is heritage technology, which frequently is
misapplied. So let's bring on the new technology for Mars Sample Return.
But a lot of the Mars Sample Return mission technology already exists.
For a Mars Sample Return mission, you need to launch to Mars, cruise to
Mars, get into Mars orbit, and get down to the surface. We've been
there, done that! We just need to do it right some more times. What is
new is sample acquisition, plus a Mars ascent vehicle - we've not yet
developed something to get off the surface of Mars. We need to put a
sample into Mars orbit, rendezvous with it, bring it back to Earth, and
do an Earth entry. And the equivalent entry, descent, and landing at
Earth has been demonstrated by the Stardust comet sample return, so
there's not a lot of new technology needed for that.
Viking today would cost 3.4 billion dollars. Mars Sample Return
estimates run from 2 to 4 billion. Can it be that Mars Sample Return
could cost less than Viking? At first, it doesn't make sense. But we
have already developed many of the elements we'll need, so that the
number of new things is much smaller than it was for the equivalent of
Viking. If you did Viking today, my rough estimate is that using today's
technology, a Viking mission would cost someplace between 1.5 and 2
billion dollars. So on a relative basis, the Mars Sample Return is more
expensive than Viking.
I'd like to suggest that future lander missions need to start caching
samples. When geologists go out in the field, you throw that first rock
in your knapsack in the morning and you keep collecting all day. At the
end of the day you may throw some out, but you've got your
representative collection. For Mars Sample Return, getting the variety
we see on Mars is important. And when you've got a mission like Mars
Science Laboratory that may go for years on Mars and maybe travel
hundreds of kilometers, we should collect samples so that we can
eventually bring some of them back home.
Now, I wouldn't claim that Mars Sample Return will be easy. Like Viking,
the devil is indeed in the details. Many people thought Viking was
impossible, yet we did it. Let's now get on with Mars Sample Return. It
will be equally challenging, equally achievable, and equally rewarding."
Received on Mon 04 Sep 2006 10:59:10 PM PDT