[meteorite-list] Returning Rocks from Mars: The Latest Plans

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:48:09 2004
Message-ID: <200110011555.IAA07068_at_zagami.jpl.nasa.gov>

http://www.space.com/missionlaunches/missions/marssample_return_011001-1.html

Returning Rocks from Mars: The Latest Plans
By Leonard Davis
space.com
01 October 2001

WASHINGTON -- The robotic reach to the Red Planet includes grabbing, bagging
and then shipping Martian soil and rocks back to Earth.

But bringing home the goods, Mars style, is neither easy nor cheap to do. In
terms of engineering difficulty, some officials call it "Apollo without
astronauts."

For years, NASA has wrestled with numerous cash and carry concepts to return
chunks of the extraterrestrial terra firma, enough material so
electron-microscope peering scientists can get a hands-on feel for Mars.
Scrutiny of those bits and pieces may well reveal a message of life. Whether
it's old news or a fresh communique from the Sun's fourth planet is part of
the allure.

Bolstered by the purported finding of microfossils in Mars meteorite ALH
84001, top NASA officials once ballyhooed plans to have Martian material
here on Earth by 2005. That enthusiasm was squashed with the back-to-back
Mars Climate Orbiter and Mars Polar Lander losses.

Now under way is another look at how best to return Martian samples to
Earth. Industry and NASA teams are scoping out a strategy to scoop up a
healthy serving of Mars and lob it our way. On the table is a novel approach
to utilize the space shuttle as part of the Mars-to-Earth transportation
link.

No stone unturned

Since earlier this year, the Jet Propulsion Laboratory (JPL) in Pasadena,
California, and four major aerospace firms have been in collective deep
thought when it comes to landing the big one -- getting some of Mars here on
Earth. The prime companies involved are Ball Aerospace; Boeing, Lockheed
Martin; and TRW.

"We're leaving no stone unturned," said Steve Matousek, deputy manager of
JPL's Advanced Studies Office for plotting out solar system exploration.
Reports from the industry partners are due in late October, with teams
honing in on approaches to reduce risk, contain costs and select the best
technologies to do the job, he said.

Any Mars sample return is a series of tough-to-do, ship-and-shoot steps. And
all of it done robotically.

Get to Mars; plop down on the surface; grab samples; load them into a
rocket; launch the precious cargo off the planet; get the freight from afar
safely down on Earth. Add on the critical need that Martian rock and soil
should be kept in tip-top shape. That is, don't foul the samples with
bacteria brought from our world and, more importantly, take precautions that
the specimens don't contain microbial misfits harmful to Earth biology,
including us.

Assuring protection of the sample, as well as maximizing safety in bringing
Mars grab bag into Earth's biosphere "are paramount requirements," said
Richard Mattingly, JPL's technical manager for the industry studies. "It's a
very complicated mission. That's why these industry looks are needed."

Paper idea to reality

Matousek and Mattingly said piecing together a viable Mars return sample
effort could involve testing technologies in Earth orbit or deep space
before committing to a full-up mission.

"Are there flight demonstrations near Earth or deep space demonstrations
that need to be done? The jury is still out on that," Matousek told
SPACE.com.

Matousek said that industry and NASA experts are mulling over an array of
options to transform Mars return sample from paper idea to reality.

Among them: Should standard chemical propulsion or ion engine oomph -- like
that used on the Deep Space 1 mission -- be tasked to get to Mars and spiral
down into low Mars orbit? Is it better to have a lander fly directly from
Earth, rather than deploy it from Mars orbit? Once on Mars' surface, is a
rover needed, or can a lander drill down, contain, and then hurl samples off
the planet from its touchdown spot? Once off Mars, should the sample be shot
outward for robotic pick-up in low Mars orbit or to a more distant
Mars-Sun-Earth gravitational balance point? For the return-leg, do you use a
chemical rocket or ion engine to boost the sample directly back to Earth, or
first put it into Earth orbit for capture by a space shuttle?

These and other trade-offs are being meticulously analyzed, Mattingly said.

A given is for the mission to be launched in 2011, but teams are also
looking at a 2013 time frame too. Anywhere from a little over a pound to
approximately double that (500 grams to one kilogram) is the wished-for
weight of the returned samples.

Price tag for the mission? "The constraint given to the industry teams is in
the $1 billion to $2 billion range. We felt, if it passed the $2 billion
mark, it just didn't fit into the program," Matousek said.

"There isn't anything aside from budget that says we couldn't do it in 2011.
So it depends on how the budget in the future goes," Mattingly added.

Vaulted landing

John Connolly, a key thinker in the NASA Johnson Space Center's (JSC)
Exploration Office, welcomes the revived looks at how to snare and shoot
back fresh ground from Mars.

"There are new technologies on the horizon, like solar electric propulsion,
that might enable you do things in entirely new ways. Those technologies
didn't exist when some of the early decisions were being made about Mars
sample return," Connolly said.

Engineers at the Houston-based space center see a blend of solar electric
propulsion and the unique attributes of the space shuttle to land Mars
materials on Earth. For one, using a shuttle means a Mars return vehicle
wouldn't require reentry shielding to thwart the high-temperature loads as
the craft plunges through Earth's atmosphere. That blistering heat could
alter the sample and thus compromise the total amount of science information
held within the Mars material.

Also, leaving reentry shielding here on Earth is a welcomed weight-savings
bonus for spacecraft designers.

Connolly said the shuttle option being proposed features a rendezvous with a
solar electric-propelled Mars return vehicle in Earth orbit. The shuttle's
robot arm then plucks from space either the entire return vehicle or
extracts the smaller sample canister. The arm gingerly tucks the hardware
into a specially built "vault" or "casket" mounted within the shuttle's
voluminous cargo bay.

With the Mars sample in tow, the shuttle glides back to Earth for a wheeled
landing.

In the event that something dire happens during the shuttle's landing phase,
the vault is beefed up to take a crash impact, Connolly said. "This idea
combines the inherent reliability of the shuttle and the vault's
reliability, giving you a system that we thought would work pretty well," he
said.

"I think the public would be very confident that the shuttle could do the
job," Connolly said.

Untouched stuff

A top priority is the ability to return Mars samples in a way that insures
their safety, said David McKay, NASA's chief scientist for astrobiology at
the Johnson Space Center.

"The real buzz word is containment," McKay said. "You make sure the samples
are contained all the way back. Then you put them into a Level 4 biohazard
facility where you work with them and determine, number one, if the samples
carry anything alive. Number two is, if it is alive, then is it safe or
dangerous?"

Some scientists argue that Mars samples should be sterilized, to make sure
that viable Martian organisms are dead on arrival, or shortly thereafter.

McKay said that, even sterilized, if there's any life in the samples,
detection should be possible.

"It would be nice to leave it unsterilized. We could then do things like
amplify the DNA. We would need to have untouched stuff. I think it is
possible, perhaps, to even culture it [Martian life], study it and figure
out its physiology. You can't do that if the samples are sterilized," McKay
said.

Solid case for containment

"We think we understand containment quite well. There's still work to be
done for sure," said David Lindstrom, a scientist at the Johnson Space
Center. He is leading the center's effort in the handling of Mars return
samples.

Lindstrom said that, even with the Mars sample return mission under way
within the second decade of this century, it's not too soon to sort out
containment and handling procedures, as well as the requisite hardware and
facilities.

"There's lots of room for improvement. On the other hand, we have more than
a decade to worry about it ... and counting. So we're trying to do some of
the basic studies to make a solid case for containment. Because, ultimately,
we have to take that to the public and convince them," Lindstrom said.

"The public have real concerns and they are going to be seriously addressed,
but it takes time," Lindstrom said.

Political correctness

Central to the ability of returning samples from Mars is the issue of
planetary protection, said Pascal Lee, a research scientist at the SETI
Institute in Mountain View, California. "It doesn't mean it's an actual
risk. What it means is that it's an issue."

"The issue is to what extent are we contaminating Mars if we were to send
humans there? To what extent is Mars going to contaminate the Earth, and
particularly humans, if we brought back samples from Mars, fresh out of the
Mars incubator, so to speak?," Lee said.

Lee said that those individuals who dismiss these issues are not doing the
science right. You cannot guarantee that Mars today is not an abode for
life, and that life there would have no effect on human beings, he said.

"You can argue at length as to how likely it is. But at the end of the day,
if you think about the potential of what's really at stake, it's humanity
versus a microbe," Lee said.

Space station stopover?

Ultimately, Lee said, how we handle Mars samples will have relatively little
to do with the actual risk that's involved. "It will have to do with
appeasing the public and public perception in particular," he said.

This being the case, the SETI Institute scientist said that any scheme of
returning samples directly to the Earth is unlikely to be acceptable. A more
politically correct scenario is first capturing the Mars samples via the
shuttle, and then preprocessing or quarantining those materials aboard the
International Space Station, Lee said.

Having the station double as an extraterrestrial receiving lab is not free
of headaches, however.

Contact between crew and the Mars samples is a worry. For instance, station
personnel would need to be mindful of possible "cling-ons".

Several experts caution that a Martian dust cloud might cling to the Mars
return craft, held there by electrostatic force. Similarly, a space probe
faring that opens and closes could release Martian dust too -- a problem now
shorted to "fary dust".

NASA's McKay adds that using the International Space Station (ISS) for
preliminary study of Mars samples would be a tough assignment. The kind of
equipment necessary, the protocols required due to the microgravity, and
having the right people on duty to do the work argues against the idea, he
said.

Yet, by studying the Mars samples in orbit, Lee said, scientists might
garner a better sense of exactly what hazards exist -- from the standpoint
of transporting those samples to Earth.

"This is an interesting, possible evolution of the ISS within the next
decade," Lee said. "We would essentially create a spaceborne analytical
capability which can then be sent to the Moon for rock analysis, or adapted
for use as an astrobiology lab on a future human mission to Mars."
Received on Mon 01 Oct 2001 11:55:05 AM PDT