Biomedical scientists at the Johns Hopkins School of
Medicine have won a $750,000 NASA grant to design the
prototype for a mini mass spectrometer that fits on a Mars
Rover and can analyze the chemicals of life as it crawls
over the Red Planet's dust.
Pharmacologist and molecular scientist Robert J.
Cotter said that a team including specialists from JHU's
Laboratory and the University of California, Santa
Barbara are designing the tailored mass spec to probe Mars
core samples for evidence of proteins or genetic
information-carrying nucleic acids in a 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 Cotter,
a professor in the
School of Medicine, who developed the design concept
for the specific type of mass spectrometer — a
low-voltage ion trap mass spectrometer — that will be
used in this mission.
Mars is one of four so-called terrestrial planets with
a metal core and rocky surface in Earth's solar system.
Researchers hope that by studying Mars' past and present
biological potential they can better understand how life
started on Earth as well as Mars' habitability.
The assignment is a natural for Cotter, who for almost
30 years at Johns Hopkins has been designing and improving
mass spec's ability to measure a chemical's mass (size and
weight). Every protein is composed of chemicals with a
distinct "mass" profile, which can be used to deduce the
contents of an unknown sample.
"Where once we had to use pure samples to get a
reading, we are now beginning to look at whole cells, which
contain thousands of different proteins, and get a catalog
of what's in the mix," said Cotter of how mass specs have
While getting better, the tool has gotten smaller as
well, he said. "Original versions were just so big and took
up so much space that it was impossible to do much else in
the lab," said Cotter, adding that the components now can
fit into a machine the size of a mini-fridge. For a mass
spec to be able to sit on a Rover for travel via rocket all
the way to Mars, however, Cotter and his team will have to
design a small one, the size of a shoebox.
"It's going to be tough, not only to miniaturize all
the intricate functions but to build the instrument to
survive the harsh travel conditions en route and the
environmental conditions once it lands," Cotter said. In
addition, he said, Mars is dusty, a condition that could
interfere with fine machinery and circuitry.
True to his medical school base, Cotter's interest in
mini mass spectrometers is not limited to the search for
Martian life. The devices hold promise as powerful
diagnostic tools, he said, and may someday be used in the