Eliminating dead bugs on Mars-bound spacecraft, designing a skin-tight space
suit and retrieving small objects that float away in space stations were some
of the topics that came up during an international videoconference hosted by
the MIT Mars Society on May 15.

“From Earth to Mars,” which was videocast to MIT students in Rm 9-057 and to
five French universities, included speakers Kenneth Jewett, a Jet Propulsion
Lab/NASA engineer; Dava J. Newman, associate professor of aeronautics and
astronautics at MIT; and Leopold Eyharts, a French astronaut who once spent
several weeks on Mir, the Russian space station.

Some of the challenges in designing a vehicle for Mars’s surface are the
extreme temperatures and low surface pressure on the planet, said Mr. Jewett,
who worked on the Pathfinder mission, the Shuttle Radar Topology Mission
(SRTM) and the Mars 2001 Lander mission, which was to have been another
small rover mission.

Mr. Jewett, who is building and testing a large prototype rover for a
possible use on the 2007 Mars mission, pointed out that most electronics
are tested to -40 C., while Martian nighttime temperatures can drop to -80
C. Surface pressure is equivalent to an Earth altitude of around 130,000
feet. And how do you navigate a vehicle from millions of miles away?

The 2003 Rover, a 150-kilogram machine with a robotic arm and 10-inch
diameter wheels, will have stereo cameras and lasers that will reconstruct
the objects in front of it. This will allow controllers to decide
whether to drive over, around or through those objects. It will travel
approximately 1 kilometer. The vehicle planned for 2007 may be as big as
a car and travel “tens of kilometers,” Mr. Jewett said.

“One of the really fascinating aspects of going to Mars is planetary
protection,” he said. “We are committed to not contaminate another world.”
To that end, he said engineers are dealing with the extremely difficult
problem of how to ensure that there is no biological material on a
spacecraft when it leaves Earth, including tiny spores. “There were a
lot of dead bugs on the Pathfinder spacecraft,” he said. They didn’t
cause any problems, but scientists will want to be sure that they when
they comb a spacecraft returning from Mars for signs of life, they are
not looking at ones that hopped a ride from Earth.

Engineers are toying with the idea of washing an entire spacecraft with
a hydrogen peroxide plasma. Others are less worried with inadvertently
creating interplanetary colonies of microscopic spores and more worried
about life forms that the spacecraft might pick up on Mars. “How do you
ensure not bringing back some evil microbe that will wipe out all life
on Earth?” Mr. Jewett said.

A SUIT OF BIOSENSORS

Professor Newman, who is also a Harvard-MIT Health Sciences and Technology
MacVicar Faculty Fellow, teaches space biomedical engineering. She talked
about the challenges facing astronauts on human missions to Mars.

Astronauts on a mission lasting months could suffer from muscle atrophy as
well as loss of muscle strength and 1-2 percent of bone density every month.
“The job we have to do is make sure this doesn’t happen,” Professor Newman
said.

She envisions a “skinsuit” or biosuit, as tight as those worn by Olympic
athletes for speed-skating and other sports, filled with biosensors that
would give NASA staff back on Earth a constant reading of the astronauts’
vital signs. The suit would be mobile and lightweight, yet able to provide
mechanical counterpressure to offset the lack of atmospheric pressure.

Ideally, the suit, with remote-controlled propulsion assistance, would even
be able to help the astronauts walk as soon as they arrived on Mars. This
would enable them to start to rehabilitate their partially atrophied
muscles immediately.

LOST IN SPACE

Former fighter pilot and test pilot Eyharts, a colonel in the French air
force, is a European Space Agency astronaut in training at the Johnson
Space Center in Houston. From an astronaut’s point of view, he said, the
trip to Mars will be more demanding than a trip to the International Space
Station because there is no reserve vehicle and less support from ground
control to command and control the spaceship. If something goes wrong,
“the crew is on its own to solve real-time problems,” which may include
in-flight maintenance of the ship itself.

While he was on Mir, Col. Eyharts found that a too-sudden or too-forceful
movement in zero gravity could send you smashing into a wall. “You don’t
have to push too hard on your arms and legs to move,” and it was difficult
to get used to working “in a world where everything is floating,” he
said. He lost a lot of small pieces involved in the experiments he was
performing, but the Russian crew members were able to recover them because
they knew where the air currents within the space station tended to take
free-floating objects.

Col. Eyharts said he believes humans will be better than robots at
performing scientific experiments on Mars. “I don’t think robots can
perform scientific work in the same way humans can do it,” he said.

In spite of the technical, physical and mental obstacles a trip to the red
planet would entail, “I think ultimately humans will go to Mars simply
because we want to do it,” Mr. Jewett said.

The five French schools that participated in the videoconference are …cole
des Mines de Paris, …cole Nationale Supèrieure de Mècanique et
D’aèrotechnique, Supèlec, …cole Nationale Supèrieure de l’Aèronautique et
de l’Espace, and …cole Centrale de Paris.

The MIT Mars Society is a chapter of the New England Mars Society. Its
aims to further the goals of the human exploration and settlement of Mars
through public and political outreach and education. It also undertakes
technical projects and encourages the involvement of the MIT community.

IMAGE CAPTIONS: [http://web.mit.edu/newsoffice/tt/2001/may23/mars.html]
Professor Dava J. Newman shows the degree of mobility in the space suit
she and colleagues designed and which they hope will be used in a future
mission to Mars. Current space suits have feet that simply lock into
place, but those in the next-generation suit will need to be able to
move around more freely. Photo by Donna Coveney.