PASADENA, Calif. -- On Sept. 8 a spacecraft will insert into the atmosphere over Utah a glider that will spiral to Earth carrying a sealed canister containing gusts of solar wind captured over the past two years. The wind contains dust, gases and other possible evidence of the dynamics of the solar system, dynamics that have somehow given rise to the splendor of -- us. NASA's name for the canister project: the Genesis mission.
Sept. 8 will be just another day at the office here on the campus of the Jet Propulsion Laboratory, where office work is not mundane but otherworldly. JPL -- an appendage of, but not contiguous to, Caltech -- may be the only place on the planet where you can gather around a lunch table with people who, in a sense, work on another planet.
On a recent day some of them were behind a laboratory at a pile of sand that resembles the surface of Mars. They were trying to drive a rover, like the two currently on Mars. The JPL scientists were trying to operate one with the kind of mechanical defect -- an inoperative drive wheel -- that is giving a slight limp to one of the rovers on the red planet 110 million miles away.
One Mars rover was landed in a crater -- what one scientist calls "an interplanetary hole-in-one." Both were expected to rove about 600 meters, but they have covered 3,000. Their batteries are recharged daily by solar panels; they already have lasted twice as long as had been expected and may last 10 times longer.
Earth, which is constantly changing, became home for life 4 billion years ago. We know neither the conditions then nor the processes by which life ignited. However, Mars may have had an early history like Earth's. One question the rovers may answer is: Were there, long ago, pools of standing water -- standing for hundreds of millions of years -- where life could have developed?
The rovers' arms, manipulated at JPL, put instruments in contact with rocks and read their mineral contents. By drilling into rocks, through several billion years worth of settled dust, the rovers have found sediments that were formed in bodies of water. Within the next decade samples may be put robotically in canisters and launched off Mars to rendezvous with an orbiting spacecraft for a six-month trip to Earth.
It would be understandable if the people at JPL were jubilant, having just -- after a seven-year flight -- precisely inserted the Cassini spacecraft into the rings of Saturn. This multinational project will include putting instruments on Titan, Saturn's largest moon, which may have some tantalizing similarities to Earth of 4 billion years ago.