Future Mars
rovers could be equipped with a new instrument that sifts through Martian soil
for chemical signs of life.
Biomedical
students at the Johns Hopkins University School of Medicine have won a $750,000
NASA grant to design a prototype for a so-called mini mass spectrometer that
can probe Mars core samples for evidence of biological molecules such as
proteins and nucleic acids, of which DNA is made, for the European Space Agency's ExoMars mission, scheduled to launch in 2013.
"What a
mass spectrometer can identify are chemical signatures of life or the building
blocks of life that may have at some point existed on the red planet," said
Robert Cotter, a professor in the School of Medicine at Hopkins, who developed the design concept
for the proposed device.
Previous Mars missions such as the Viking
landers were also equipped with mass spectrometers but they could only
analyze gas samples.
"The thing
that's novel in this case is this is the first time anyone has attempted to
look at nonvolatile compounds," Cotter said.
The plan is
to use a laser to chip off a small bit of a sample, essentially making it
volatile. "If you take a hair, for example, and try to heat it, it will just
burn. But if you bounce a laser off it, you can knock off a few proteins and
things like that and convert it to the gas phase," Cotter explained.
The
researchers face a challenging task of miniaturizing their mass spectrometer to
the size of a shoe box. Currently, mass specs of the kind being proposed for
the ExoMars mission are about the size of a mini-fridge, Cotter said.
Another
hurdle is designing a mass spec that consumes little power. "We're aiming for
300 volts," Cotter said. "They're usually several kilovolts."
Using high
voltages on Mars is dangerous because of the risks of "arcing," visible
high-energy electrical discharges that can damage electronics. "At some volts,
between 2,000 to 10,000 volts, things are generally pretty stable in the Earth's atmosphere, but they would discharge and be just like lightning between the circuit boards on Mars,"
Cotter told SPACE.com.
Solving the
power consumption problem could help the researchers shrink the instrument. "If
there's lower power, the pieces can get smaller and the miniaturization should
be better," Cotter said.
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