From: LARRY KLAES (ljk4_at_msn.com)
Date: Tue Dec 23 2003 - 08:00:50 PST
http://www.pbs.org/previews/nova_mars/
NOVA: MARS Dead or Alive
During Earth month January 2004, a strange sight will unfold on the planet Mars. Above a vast, dry lake bed south of the Martian equator, a conical vehicle will parachute toward the surface; then, just before touchdown, it will be enveloped by a gigantic protective airbag allowing the craft to bounce safely to a stop. Inside is Spirit, the most sophisticated rover ever launched from Earth, which NOVA covers in depth on "MARS Dead or Alive," airing on PBS Sunday, January 4, 2004, 8:00 p.m. ET - just hours after Spirit lands on the red planet. An updated version of the program airs on PBS Tuesday, January 6, 2004.
NOVA's behind-the-scenes look at the construction of Spirit and its twin, Opportunity, will include a special live segment with the latest news from the red planet - to learn if Spirit has survived its risky landing and 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 not only designed to be remote-controlled field geologists, but to perform in a demanding environment millions of miles from Earth. As NOVA 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. In this way, the MER team hopes to find evidence of the liquid water that many scientists theorize was once abundant on Mars's surface but has since vanished.
The landing sites have been chosen for their strong signs of a wet past. Spirit is targeted for Gusev Crater, a possible former lake, and Opportunity will land three weeks later at Meridiani Planum, where minerals that normally form in the presence of water have been detected.
And where there's water, there may have been life. The ultimate goal of Spirit and Opportunity, if they are able to land safely, 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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