It's not science fiction, however. This real-world adventure is set to begin in less than four years, and although inspired by wild imagination, it is being guided by hard science and advanced robotic engineering. If it all succeeds, a heat-shielded capsule containing martian material will plummet to the sands of Deseret within a decade.
The Mars Sample Return 2003 and 2005 missions are to be the most ambitious robotic missions ever undertaken. They are full of risks and uncertainties and rely on technologies still being developed. Just getting a spacecraft into martian orbit is a tremendous feat of engineering that still requires a good measure of luck.
In 1992, mission control lost contact with the Mars Observer spacecraft just three days before it was scheduled to enter Mars orbit to begin a detailed mapping mission. The Russian Mars '96 Orbiter failed to escape Earth's gravity and crashed into the Pacific Ocean four hours after launch in 1996.
Reaching Mars orbit may be the simplest challenge of the planned sample-return missions. Each will land a spacecraft on the surface and dispatch a rover to collect miniature rock cores. The cores will be placed inside a rocket that will launch back into Mars orbit to await a larger return-spacecraft to fetch it and bring it to Earth.
Samples of martian rocks will give scientists insight into the formation and evolution of the Red Planet and may help answer burning questions about whether there is or ever was life on Mars.
"Certainly at the top of the list of objectives is searching for life," said Joy Crisp, the deputy project scientist of the Mars Sample Return 2003 and 2005 missions. "And tied into that is the environment -- Is there any chance that the environment is, or was, conducive to the formation of life?"
The rovers for the sample-return missions will carry a suite of scientific instruments. These include cameras and spectrometers, according to Steven Squyres, the principal investigator for the six-wheeled buggies and a planetary scientist at Cornell University. The rovers will be several times the size of the Sojourner rover that cruised on the martian soil during the Mars Pathfinder mission in 1997.
One of the keys to the upcoming mission will be the tiny drill that will extract cores from surface rocks, and load them into a cylindrical cache. After three months of surveying and drilling on the surface, the rover will return to the lander with a package of 45 cores. The cores will be about an inch long and have the thickness of a pencil.
Getting the cache into orbit will be the next difficult trick of the mission. It will require the utmost level of cooperation from the family of robotic devices. The rover will drive onto the lander and install its treasure into a hold near the rocket's tip. The current design calls for a two-stage rocket, roughly 5 feet (1.5 meters) long and weighing about 275 pounds (125 kilograms), that will lie horizontally on the lander, explains Doug Caldwell, the project manager for the rocket, which is being called the Mars Ascent Vehicle. The rover will straddle the rocket, insert the cache, then retreat. The rocket will rotate upright and blast off with about a pound (half a kilogram) of rock cores packed inside.
After that, it's a waiting game for the rocket's payload -- a satellite about the size of a softball that will orbit some 500 miles above Mars.
The 2003 sample will park in orbit for a few years, waiting to hitch a ride Earthward. Another mission in 2005 will place a second satellite in orbit.
The rendezvous ship is being built by France's space agency and will be launched in 2007. It will rendezvous with both the 2003 and the 2005 sample satellites, pick them up and bring them back to Earth. The rendezvous procedure, which may be the most difficult maneuver in the whole mission, is still being designed, mission managers said.
If the French spaceship is able to catch the two sample-bearing orbiters, it will then fire a course toward Earth, and drop them in the Utah desert in 2008.
NASA's Jet Propulsion Laboratory in Pasadena, California is managing the sample-return missions as part of the Mars Surveyor program. The program is operating the Mars Global Surveyor now orbiting Mars, and has launched the Mars '98 orbiter and lander, which are en route. Two additional spacecraft will be launched in 2001. The Mars Surveyor program has budget of more than $1.1 billion to cover the sample return missions through 2008.
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