The Mars Express spacecraft was launched by a Soyuz FG booster rocket from the Russian-operated Baikonur cosmodrome in Kazakhstan at 1:45 p.m. EDT, according to the agency.

The space vehicle, which cost US$350 million was initially put into Earth orbit, and about 90 minutes later was given the final push to 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 Martian surface on Dec. 25. The tiny lander will head to Isidis Planitia, north of the Martian equator where traces of life could have been preserved.

Scientists think 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 is 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 -- the first such search since 1976, when twin U.S. Viking landers brought inconclusive results.

The mission, called 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.

NASA is sending its own twin Mars Exploration Rovers later this month in a $800 million mission to try to answer the same questions about water and life on the planet. A Japanese spacecraft launched in 1998 also continues its voyage toward Mars, despite some electronic troubles.

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 American, 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. The 143-pound lander -- too light to have a steering mechanism -- must 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 gravity to capture the vehicle.

Mars Express is to remain in its Martian orbit for at least one Martian 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.

(China Daily June 3, 2003)