The miniature laboratory, built by British scientists with the goal of searching for signs of life on Mars, had been due to land on the Red Planet on December 25 but disappeared without trace.

The lander's management board met last Friday and "following an assessment of the situation, declared Beagle 2 lost," an ESA statement said.

An inquiry will be held into the loss, chaired by ESA Inspector General Rene Bonnefoy with a former senior executive in the British space industry, David Link, as deputy chairman.

"ESA is a partnership of its member states, and sharing the lessons learnt from good and bad experiences is fundamental in cooperation," the agency's director general, Jean-Jacques Dordain, said.

Beagle 2's mother ship, Mars Express, went into orbit around Mars on Christmas Day and is operating successfully, ESA said.

The orbiter has already sent back data confirming hunches that there is abundant water ice on the planet's South Pole.

Inquiries into space failures are routine, because losses are expensive and understanding the cause for them can help future missions.

Beagle 2 separated as planned from Mars Express on December 19 but it failed to make contact with Earth after its planned touchdown six days later.

Scientists feared the craft -- designed to unfold like a pocket watch upon landing -- may have been destroyed, failed to open properly or else landed inside a crater, making communication impossible.

The probe had been lauded within the space industry as a triumph of miniaturisation, although critics said that because it was such a small payload, it had no backup if one of its vital systems malfunctioned.

Another criticism was that because Beagle 2's budget was so tiny and the time given to building it was so scant, there had been little chance for carrying out equipment tests.

Beagle 2 weighed just 33.2 kilos (73 pounds) of which a third was given to scientific tools, the highest scientific ratio in any package ever flown into space.

It was named honour of HMS Beagle, the ship that took Charles Darwin, the pioneer of the theory of evolution, on his historic 1831-36 trip around the world.

Beagle 2's budget is secret, but it is unofficially estimated at around 30 to 50 million pounds (45-75 million euros, 56-94 million dollars), about a tenth of the budgeted cost of each of the two US rovers now successfully deployed on Mars.

SPACE.WIRE