The Russian-led Mars '96 spacecraft is scheduled to launch tomorrow, carrying with it 24 scientific instruments and the future of the Russian exploration of Mars. The ambitious payload includes experiments to probe the planet's soil, inner structure, atmosphere, and plasma envelope--the charged ions surrounding the planet.
The spacecraft should drop two landers by parachute to the planet's surface and launch two dart-shaped penetrators, designed to bury themselves about 6 meters deep in Martian soil. Their instruments will record the temperature, chemistry, and mineralogy of the soil as well as any seismic activity.
The project, which has involved scientists from 22 countries, was originally scheduled for launch in 1992, but political turmoil caused 4 years of delays. The upheaval in Russia made scientific cooperation much more difficult, says Howard Shaw of the University of Kent in Canterbury, U.K., who helped design one of the penetrator instruments: ''It's been a long process, and a hard slog.'' But he has high praise for the dedication of the Russian scientists, who often go several months without pay.
If the project succeeds, the rewards will be rich, says Bruce Murray, a planetary scientist at the California Institute of Technology. ''If even 50% of this works,'' he says, ''it will be the most important Mars mission since Viking [the U.S. spacecraft that landed on Mars in 1976]. The Russians will become, at least temporarily, the primary Mars players.'' A failure, however, would make already reluctant international partners even more hesitant to cooperate.
If the launch goes as planned--this afternoon the skies were clear for hundreds of miles surrounding the launch site in Kazakhstan--the spacecraft will reach the Red Planet on 12 September 1997, the same day as NASA's Global Surveyor that launched on 7 November. Mars Pathfinder, which NASA plans to launch on 2 December, will take a shorter flight path to Mars, and is scheduled to arrive at Mars early next July.