FRANKFURT (Reuters) - A Mars lander left its mothership on Sunday after a seven-month journey from Earth and headed toward the red planet's surface to test technologies for Europe's planned first Mars rover, which will search for signs of past and present life.

The disc-shaped 577-kilogramme (1,272 lb) Schiaparelli lander separated from the spacecraft Trace Gas Orbiter (TGO) at 1442 GMT (10:42 a.m. EDT) as expected, starting a three-day descent to the surface.

Signals received from TGO, which is to orbit Mars and sniff out gases around the planet, did not at first contain data on the lander's onboard status, but the European Space Agency (ESA) later said the link with the craft had been restored.

"On the side of (Schiaparelli) I would say that the separation was a success," Paolo Ferri, head of mission operations at ESA, told Reuters TV at ESA's Space Operations Centre in Darmstadt, Germany, after it had been confirmed that the lander had split from the TGO.

Schiaparelli, part of the European-Russian ExoMars program, represents only the second European attempt to land a craft on Mars, after a failed mission by Britain's Beagle 2 in 2003.

Landing on Mars, Earth's neighbor some 35 million miles (56 million km) away, is a notoriously difficult task that has bedevilled most Russian efforts and given NASA trouble as well.

But a seemingly hostile environment has not detracted from the allure of Mars, with U.S. President Barack Obama recently highlighting his pledge to send people to the planet by the 2030s.

Elon Musk's SpaceX is developing a massive rocket and capsule to transport large numbers of people and cargo to Mars with the ultimate goal of colonizing the planet, with Musk saying he would like to launch the first crew as early as 2024.

The primary goal of ExoMars is to find out whether life has ever existed on Mars. The current spacecraft, TGO, carries an atmospheric probe to study trace gases such as methane around the planet.

Scientists believe that methane, a chemical that on Earth is strongly tied to life, could stem from micro-organisms that either became extinct millions of years ago and left gas frozen below the planet's surface, or that some methane-producing organisms still survive.

Schiaparelli will reach the atmosphere of Mars on Wednesday, and will use a parachute and thrusters to slow its descent from a speed of nearly 21,000 kilometers per hour before touching down on the planet's surface. Entry, descent and landing will take less than six minutes.

The second part of the ExoMars mission, delayed to 2020 from 2018, will deliver a European rover to the surface of Mars. It will be the first with the ability to both move across the planet's surface and drill into the ground to collect and analyze samples.

The ExoMars 2016 mission is led by the European Space Agency (ESA), with Russia's Roscosmos supplying the launcher and two of the four scientific instruments on the trace gas orbiter. The prime contractor is Thales Alenia Space, a joint venture between Thales and Finmeccanica.

The cost of the ExoMars mission to ESA, including the second part due in 2020, is expected to be about 1.3 billion euros ($1.4 billion). Russia's contribution comes on top of that.

($1 = 0.9060 euros)

(Reporting by Maria Sheahan; Editing by Dominic Evans, Greg Mahlich)