Scientists sweat over Mars orbit

JITTERY NASA scientists are waiting for the most advanced spacecraft ever sent to another planet to make its risky final approach to Mars, where it is due to return 10 times the data of all previous probes put together.

NASA’s unmanned Mars Reconnaissance Orbiter, which has travelled some 300 million miles since leaving Earth in August, is due to enter its most delicate phase today, when it will try to ease into orbit around Mars.

“We’re very excited about the arrival of the Mars Reconnaissance Orbiter, but my heart rate is going up for a different reason,” said Fuk Li, Mars program manager at NASA’s Jet Propulsion Laboratory in Pasadena, referring to the dangerous manoeuvre.

If the spacecraft succeeds in reaching its planned orbit, which will take another seven months, it could collect a remarkable amount of data in its two-year mission that could help NASA determine where to land rovers and even make early plans for a human landing site on Mars.

“What we’re really looking for is that sweet spot where we can go down with other instruments and look for evidence of life,” said project scientist Richard Zurek.

The vast distance to Mars from Earth and the unpredictability of its atmosphere have been fatal to previous missions there.

NASA has only a 65% success rate in getting space probes to orbit the planet.

The hard part is getting the robot orbiter - which is as tall as a two-story building and cruising at 17,700km/h - to slow down enough to be captured by the planet’s gravity.