ExoMars mission: Schiaparelli robot probe doesn't send message to Earth as expected, potentially meaning it is lost

How the ESA had hoped the mission would proceed

If the lander has failed to land safely on the planet's surface, it has grim echoes of the Beagle 2's problems

The Schiaparelli robot probe has not sent back a message it was expected to from the surface of Mars.

The problem could mean that the lander has been lost. If so, it would bring a tragic end to humanity's newest hopes of finding alien life on the planet.

But the European Space Agency warned against writing off the chances of finding the lander. There was still a decent chance that the lander might be heard from.

Scientists will be able to check that when the proper data comes back from Mars Express, the main mission. The initial signal that scientists were looking for was simply an experimental stage meant to give very quick results – and so the more reliable message might still be sent back.

The lander did appear to successfully make its way back into the atmosphere and through the first stages of its descent. But it didn't send back the message that would usually be expected to signal that it had successfully landed on the planet's surface.

Scientists had always cautioned that the time between dropping the lander into the atmosphere and actually hearing back from it would be tense. But actually losing it would still come as a huge blow – especially in its echoes of Beagle 2, which dropped onto the Mars surface in 2003 but never managed to communicate with Earth once it had done so.

The probe left its mothership on Sunday and has been making its way to the surface of the planet ever since.

Although the probe has some instruments on board – and will use one of them to test a potential signal of life on the planet – its main job is as a test of the landing system for a much bigger ExoMars mission that's expected to launch in 2020.

That landing system sees it initially slow down as a result of the friction from the heat shield. It then deployed a parachute about 7 miles above the planet to slow it down even more, and fires rockets soon after that.

Once the landing maneuvres are all complete the rockets switch off and the probe drops all of the rest of the way to the surface.