NASA is sending its own twin Mars Exploration Rovers later this month in a $800 million mission to try to answer the same big questions about water and life on the planet, and a Japanese spacecraft launched in 1998 also continues its voyage toward Mars despite some electronic troubles.
The Mars Express spacecraft is to be launched by the Soyuz FG booster rocket from the Russian-operated Baikonur cosmodrome in Kazakhstan at 9:45 pm Monday (1:45 p.m. EDT), according to the Russian Space Forces, which runs the launchpad.
The space vehicle, which cost 300 million euros (about $350 million U.S.) will initially be put into Earth orbit, and about 90 minutes later is to be given the final push that will send it on a six-month journey to Mars — the ESA's first interplanetary mission.
Several days before the spacecraft reaches Mars in December, the British-built Beagle 2 lander is set to separate from the vehicle. It will parachute down to the Mars surface on Dec. 25. The tiny lander will be heading to Isidis Planitia, an area north of Mars' equator where traces of life could have been preserved.
Scientists think that Mars once had plenty of water and appropriate conditions for life but lost it billions of years ago, possibly after being hit by asteroids. It's believed that water might still exist on Mars as underground ice.
The lander would dig into Mars to search for organic materials and check the atmosphere for traces of methane produced by living organisms — looking for signs of life for the first time since 1976 when the twin U.S. Viking landers brought inconclusive results.
Mars Express will map the planet, use a powerful radar to probe its surface for evidence of water, and measure water concentrations in the atmosphere.
The launching of many spacecraft at once isn't accidental — celestial mechanics are bringing Mars and Earth closer together than they have been for a long time, helping save fuel and travel time.
Of 34 unmanned U.S., Soviet and Russian vehicles sent to Mars since 1960, two-thirds ended in failure.
The spacecraft that succeeded helped vastly expand human knowledge about Mars. Just 40 years ago, some experts still believed that thick vegetation grew on Mars — that belief was dispelled in the 1960s by NASA spacecraft which beamed back images of Mars' barren surface.
The operation to eject Beagle 2 will be highly delicate, as the 143-pound lander is too light to have a steering mechanism and will have to rely on the 1.3-ton Mars Express to guide it into the proper descent path by dropping it at a very precise moment at a specified speed.
Once the lander is ejected, mission controllers will have to adjust Mars Express' trajectory and reduce its speed to allow Mars' gravity to capture the vehicle in another delicate maneuver.
Mars Express is set to remain in its orbit for at least one year — 687 Earth days. Its antenna will receive data from Beagle 2 and the orbiter's own instruments and beam it to Earth in daily communication sessions.
By Vladimir Isachenkov