NASA has selected a proposal for a mission that would
collect samples of martian atmospheric dust as one of four
finalists for the first Mars Scout mission (see NASA press
release). The proposal, directed by Arizona State University
geologist and cosmochemist Laurie Leshin, will receive a
$500,000 grant to complete its development prior to the
agency’s final selection process, which will begin next
summer. The Mars Scout Program plans to mount at least one
(and perhaps several) Scout missions to Mars beginning in
2007, with budgets of up to $300 million per mission.
Leshin’s proposal is called “Sample Collection for
Investigation of Mars” (SCIM), and involves a mission that
would do a hit-and-run with the dusty Martian atmosphere.
The proposed mission would perform the first return of a
Martian sample at less cost, lower risk and in a shorter
time frame than the far more complicated missions that
will eventually be launched to collect samples from the
planet’s surface. For full details on the mission
proposal, including images and animations, see
http://scim.asu.edu .
In brief, the proposal calls for a spacecraft to make a
“high pass” of Mars, going within 25 miles of the planet’s
surface and to collect samples from the Martian atmosphere
for about one minute at about 12,300 miles per hour, before
swinging back and beginning the return to earth. On the
spacecraft, a light-weight and porous high-tech substance
known as “aerogel” would cushion, trap and preserve dust
particles. The aerogel collection device is similar to the
device on the Stardust mission to collect dust streaming
off of a comet.
Leshin projects that the aerogel would capture about 1000
fine dust particles measuring 10 microns (1/100 of a millimeter)
or larger. “Martian dust is an interesting thing because there
is dust all over the Martian surface,” said Leshin. “It’s the
ubiquitous layer – it’s everywhere, yet we really know very
little about it. It samples virtually the whole planet, yet it is
so fine-grained that it is very hard to study when you’re sitting
there on the surface. You really need to bring it back to Earth to
characterize it grain by grain. And each grain is like a little
rock from Mars.”
Dr. Leshin is currently at the American Geophysical Union meeting
in San Francisco, but can be reached by cellular phone at
602-430-0067, or in her hotel at 415-771-1400, room 4282.
