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On January 3, 2004, a strange sight unfolded on the planet Mars.
Above a vast, dry lake bed south of the martian equator, a conical
vehicle parachuted toward the surface. Then, just before touch down,
it was enveloped by a gigantic protective airbag allowing the craft
to bounce safely to a stop. Inside was Spirit, the most
sophisticated rover ever launched from Earth. "MARS Dead or Alive,"
which originally aired just hours after Spirit landed on the
red planet, covers this mission in depth.
The program's behind-the-scenes look at the construction of
Spirit and its twin, Opportunity, includes a special
up-to-the-minute segment with the latest news from Mars as of
January 3, 2004—to learn if Spirit is ready to
undertake the most comprehensive search for evidence of liquid water
ever attempted on Mars.
NOVA spent months documenting the tension-filled process of
building, testing, final checkout, and launch of a pair of
spacecraft that are designed not only to be remote-controlled field
geologists but to perform in a demanding environment millions of
miles from Earth. As the program shows, unexpected problems with
designs for the parachute and airbags almost scuttled the mission,
and a potentially catastrophic electronic problem on
Spirit didn't turn up until the vehicle was completely
inaccessible and awaiting launch.
Riding on the mission are not just the hopes of scientists seeking
to answer baffling questions about the history of Mars, but the
future of NASA's Mars exploration program itself. Twice in 1999 NASA
probes arriving at Mars were lost without a trace. One of the few
recent bright spots for Mars research was the surprising success of
the experimental lander-rover Pathfinder in 1997, which was designed
to test the airbag-landing technique.
Pathfinder was spawned by a freewheeling group of young scientists
and engineers who are now back with the far more ambitious
Spirit and Opportunity vehicles, which make up what is
officially called the Mars Exploration Rover (MER) project. The MER
science team is headed by planetary scientist
Stephen Squyres of
Cornell University, who conceived the project with the goal of
probing the most burning questions in Mars science: Was there ever
liquid water on the Red Planet? Were conditions ever suitable for
life?
Spirit and Opportunity are mobile laboratories
outfitted with visible-light and infrared cameras to scan the
landscape and locate promising rocks for investigation; a power tool
to grind off the weathered surface; a microscope to examine the
interior; and two other instruments to sniff out the rock's
chemistry. (For a closer look at a MER, see
Anatomy of a Rover.) In
this way, the MER team held out hope of finding evidence of the
liquid water that many scientists theorize was once abundant on
Mars's surface but has since vanished.
The landing sites were chosen for their strong signs of a wet past.
Spirit is now on site in Gusev Crater, a possible former
lake, while Opportunity has been exploring Meridiani Planum,
where minerals have been detected that normally form in the presence
of water. And where there's water, there may have been life. The
ultimate goal of Spirit and Opportunity is to shed
light on this intriguing possibility and perhaps pave the way for
the most versatile explorers of all—humans.
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The spacecraft housing one of the rovers heads to Mars
in a NASA animation.
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