A European lander is to separate from its mothership Sunday for a million-kilometre (621,000-mile) descent to Mars, testing vital technology ahead of a mission to explore the Red Planet for signs of life.
Separation is scheduled for 1442 with the landing due to take place on Wednesday, according to the ESA website. The operation is a testbed for the second chapter of the so-called ExoMars mission, a joint exploration with Russia. The second part will begin in 2020 with the launch of a rover designed to move around and drill into Mars in search of extra-terrestrial life — past or present. Sunday’s separation manoeuvres will be followed closely by mission controllers in Darmstadt, Germany, 175 million kilometres away.
Mars has been a graveyard of space dreams. Sending an unmanned mobile explorer is especially tricky. Rovers have to arrive intact after a long trip across space, followed by a descent through Mars’ thin, carbon dioxide atmosphere.
The descent itself is an acrobatic feat, requiring protection from atmospheric friction, extreme braking just above the surface and then a soft touchdown in terrain where any jagged rocks and craters could spell doom. So far, only the United States has successfully operated rovers on the planet. In 2003, ESA sent down a small lander, Beagle 2, from its highly successful Mars Express orbiter.
But the cone-shaped craft, packed with tiny instruments but built on a limited budget, disappeared without trace. Its fate remained unknown until 2015, when composite images by the US Mars Reconnaissance Orbiter suggested Beagle 2 had landed intact but its solar panels had failed to open fully.
After releasing its precious charge on Sunday, the TGO will change course to avoid crashing into Mars. It will enter an eccentric orbit of the Red Planet next Wednesday, as Schiaparelli reaches the atmosphere at an altitude of some 121 km and a speed of nearly 21,000 kph.
The hot and bumpy ride through Mars’ atmosphere will take six minutes.
A discardable “aeroshell” will protect the lander against heat generated by atmospheric drag, while a supersonic parachute and nine thrusters will brake the descent. A crushable structure in the lander’s belly is meant to cushion the final impact.
With a 10-minute delay — the time it takes for a message to reach Earth — Schiaparelli will send data on temperature, humidity, density profile and electrical properties — information seen as crucial to plan a safe landing for the much bigger and more expensive rover. Battery-driven and without solar panels, the lander should last for two or three days.
The TGO will get to work in early 2018, sniffing Mars’ atmosphere from an altitude of about 400 km for methane, which scientists believe may be excreted by microbes living underneath the barren, radiation-bombarded surface.
