NASA is preparing for disaster. The space agency is taking a leaf out of the
airline industry鈥檚 book and is designing a 鈥渂lack box鈥� flight data recorder for
all its future Mars missions. The hope is that a lot of the guesswork can be
taken out of any inquiry into a future failed mission.
鈥淚t鈥檚 an idea that been kicked around for a while, but after the loss of Mars
Polar Lander we decided to go ahead and develop a recorder,鈥� says Lynn Lowry,
the project鈥檚 leader at NASA鈥檚 Jet Propulsion Laboratory in Pasadena,
California.
Lowry鈥檚 team is designing the recorder to withstand the kind of crash impacts
undreamed of by aircraft makers. Whereas a plane鈥檚 data recorder is designed to
withstand impacts of 3400 g
(New Scientist, 17 October 1998, p48),
Lowry says recorders on a Mars probe would have to withstand forces of
between 15 000 and 20 000 g.
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To attain this strength, the spaceflight recorder will be built around an
ultra-stiff titanium grid covered with Kevlar, the material used to make
bullet-proof vests. Circuit components, such as the memory chips on which it
records, will be built into the ultra-stiff frame to avoid using fragile circuit
boards. This will allegedly improve robustness and keep the recorders鈥� mass to a
minimum鈥攊t must be no more than 7 kilograms, says Lowry.
The new recorder is not designed to be retrieved and examined forensically.
Rather, it will beam key crash data to an orbiter when queried by it. This will
then relay the data to Earth. And unlike most aircraft, whose voice and flight
recorders lose power when the aircraft does, hampering investigations, the
recorder will have its own battery power. The recorder鈥檚 strength will be tested
this summer by firing it from a cannon, says Lowry. It could be flying on a Mars
mission in 2003.
John Thatcher, a spokesman for the European Beagle 2 Mars lander鈥攁lso
hoping to fly in 2003鈥攕ays of JPL鈥檚 spaceflight recorder: 鈥淚t鈥檚 a nice
idea. But on something as small as Beagle 2, where we are trying to pack as much
science in as possible, adding any more mass at this stage for something like a
flight recorder would be impossible.鈥� He says that at 60 kilograms, Beagle 2 is
about one-tenth the mass of NASA鈥檚 Pathfinder lander, which released the
Sojourner rover on Mars in 1997.