The British-built Beagle 2 Mars probe today successfully separated from its mother ship, and headed to the Red Planet to search for signs of life.
The probe is scheduled to land on the planet's surfgace on Christmas morning and will gather and sample rocks for evidence of organic matter and water. At the same time, the Mars Express spacecraft that launched the probe is to orbit overhead collecting radar data.
"I'm very proud to say we have made a big step toward getting to Mars, but this is really only the beginning," said David Southwood, the European Space Agency's director of science.
"Mother and baby are both doing very well. But we've got to wait until Christmas day to make the next major step."
In the control room at Darmstadt, Germany, screens flashed to red to indicate the successful launch, but with critical maneuvers still ahead the reaction was one of hushed relief.
"It was relief, absolutely, we have all been waiting for this moment for a long time and when our screens lit up we were ecstatic," said Zeina Mounzer, the Mars Express mission head of simulations.
The mission is the first to try to determine if there is life on Mars since twin US Viking landers searched for life in 1976 but sent back inconclusive results. Of 34 unmanned American, Soviet and Russian missions to Mars since 1960, two-thirds ended in failure.
"It's not looking for little green men, but it is looking for matter that might provide evidence of life. It is looking for clues," Southwood said earlier.
The probe's launch was the first in a series of critical navigational manoeuvres on which the success of the mission depends. Getting the Mars Express into orbit is the next.
During the launch, the spacecraft gently pushes the probe away, setting it spinning to maintain stability as it heads toward Mars. It is expected to reach its destination early on 25 December
At the same time the probe is to reach the surface, mission engineers plan to position the Mars Express craft to fire its main engine for about 30 minutes, sending it into Martian orbit, around 400 250 miles above the surface. Once there, the Express will use radar to penetrate the surface looking for layers of water or ice - in addition to relaying data from the Beagle 2 to mission control.
"This is the first time we will be looking under the surface of Mars using radar," Mr Southwood said.
The Mars Explorer, which cost about $345 million, is an attempt to demonstrate that Europe can have an effective - and relatively inexpensive - space exploration program.
Launched atop a Russian Soyuz-Fregat rocket from the Baikonur cosmodrome in Kazakhstan in June, Mars Express has weathered solar eruptions that bombarded it with high-energy particles, temporarily disrupting its computers, as well as an unexpected drop in electrical power.
The 143lb Beagle 2 - named after the ship that carried naturalist Charles Darwin on his voyage of discovery in the 1830s - will use a robotic arm to search for organic material in the Martian soil. It also will sample the atmosphere for traces of methane, a telltale byproduct of many biological processes.
During the Mars Express' working life - planned for one Martian year, or 687 Earth days - engineers hope the space craft will send back detailed pictures of the planet's surface and use a powerful radar to scan for underground water.
Scientists think Mars, which still has frozen water in its ice caps, might have once had liquid water and appropriate conditions for life but lost it billions of years ago. It is thought water may also still exist as underground ice.
Earlier this month, Japan was forced to abandon its troubled mission to Mars, to determine whether the planet has a magnetic field, when officials failed in their attempts to position their Nozomi probe on course to orbit the planet.
US officials are discussing a new course of space exploration, and debate has focused on whether the United States should set its sights on returning to the moon or landing on Mars.Reuse content