26/07/2012 10:49 BST | Updated 25/09/2012 10:12 BST

Nasa Recovers Key Mars Satellite Ahead Of 'Most Difficult' Mission To Land On Surface

Nasa has made one of its final adjustments before attempting its 'most difficult' Mars landing.

The Curiosity rover is set to land on Mars at about 5.30am GMT on 6 August, ahead of a two-year mission to explore the planet's surface.

Nasa had previously announced it had lost contact with a key satellite above the planet, meaning it would have been difficult to know if the rover had landed successfully until some time after.

The Curiosity rover will not be able to send information back to Earth directly during the landing, because Earth will have 'set' below Mars' horizon by that time.

But now the space agency says it has successfully adjusted the Mars Odyssey spacecraft.

"Information we are receiving indicates the maneuver has completed as planned," said Mars Odyssey Project Manager Gaylon McSmith of nasa Jet Propulsion Laboratory.

"Odyssey has been working at Mars longer than any other spacecraft, so it is appropriate that it has a special role in supporting the newest arrival."

If the rover makes it down safely it will be used to look for signs of life and water which may have once existed on the surface.

But landing the vehicle in the targeted 96-mile-wide crater will not be easy. The rover weighs more than a ton, and the 'air bag' technique used to launch previous, smaller robots won't work - meaning a new, relatively risky landing method has to be attempted instead.

The craft will have to "fly like a wing", Nasa said, before a backpack with retro rockets will fire, controlling the speed of the craft before lowering the rover on three nylon cords.

The new method is known as a 'Sky Crane' and has not been tried before.

"The Curiosity landing is the hardest NASA mission ever attempted in the history of robotic planetary exploration," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate, at NASA Headquarters in Washington.

"While the challenge is great, the team's skill and determination give me high confidence in a successful landing."

But despite the issues, Nasa remains confident about the mission.

It is also on track to return to the red planet with astronauts by the end of the 2030s, it said.