European ExoMars spacecraft ready to send Schiaparelli lander to Mars surface
A European spacecraft nearing the end of its journey to Mars is ready to send a lander to the surface of the Red Planet.
Time-saved command signals for the landing on October 19 were uploaded into ExoMars Trace Gas Orbiter's computers on October 3 and October 7.
The European Space Agency (Esa) probe, part of an ambitious mission to search for evidence of life on Mars, was launched on March 14 and has almost completed a 310 million mile (500 million km) voyage across the solar system.
It is due to deploy the small Schiaparelli lander on October 16.
Three days later, Trace Gas Orbiter (TGO) will brake into an elliptical orbit around Mars while Schiaparelli enters the Martian atmosphere and parachutes down to the surface.
The 8ft (2.4m) wide disc-shaped craft will aim for Meridiani Planum, a flat region near the equator.
Its main mission is to pave the way for ExoMars Rover, a hi-tech six-wheeled laboratory equipped with life-seeking instruments to be launched in 2020.
Schiaparelli will test the rover's Russian-designed descent and landing system - which employs a heat shield, parachute, and retro rockets.
It also carries a small instrument package that will record wind speed, humidity, pressure and temperature at the landing site - and take electric field measurements that may shed light on how Martian dust storms are triggered.
Orbiter flight director Michel Denis said: "Uploading the command sequences is a milestone that was achieved following a great deal of intense cooperation between the mission control team and industry specialists."
The spacecraft is being controlled from the European Space Operations Centre (Esoc) in Darmstadt, Germany. However many of its systems are automatic and not dependent on direct commands from Earth.
Schiaparelli's command sequences are time-saved to ensure the lander can carry out its mission even when out of contact.
During the landing, the command signals will eject the front and back aeroshells, operate descent sensors, deploy the braking parachute, and activate three groups of hydrazine retro rockets.
At around two metres (6.5ft) above the surface, Schiaparelli will hover briefly before cutting its retro thrusters and dropping to the ground.
Once down, it is programmed to keep its science instruments running for at least two days.
TGO will play a key role in the ExoMars mission from orbit as it looks for rare gases in the planet's atmosphere including methane, which can only come from an active source.
The probe will tell scientists whether Martian methane is most likely to have a geological or biological origin.
On Earth, the gas is chiefly generated by billions of bacteria, many of which live in the guts of animals such as cows. But it can also be released by the breakdown of organic molecules deep underground or volcanic activity.
The two-stage £1 billion (1.2 billion euro) joint European and Russian ExoMars mission is equipped to uncover the first clear evidence of past or present life on Mars, if it exists.
The British-designed rover, built by Airbus Defence and Space at its UK headquarters in Stevenage, will drill samples from the Martian soil and analyse them for biochemical signatures of either long-dead or still living organisms.
Scientists have not ruled out the possibility that bugs may survive beneath the planet's radiation-baked surface.
TGO will not begin its science mission until the end of 2017, after a year of complex manoeuvres to circularise its orbit.