U.S. scientists test radar system for Mars landing

LOS ANGELES, April 13 (Xinhua) -- U.S. scientists have been conducting a series of tests on a radar system that will serve during the next landing on Mars, NASA's Jet Propulsion Laborotary (JPL) said Tuesday.

In one test, a helicopter carried an engineering test model of the landing radar for NASA's Mars Science Laboratory (MSL) on prescribed descent paths, JPL said on its website.

The descents at different angles and from different heights simulated paths associated with specific candidate sites for the mission, said JPL.

The MSL mission, managed by JPL, headquartered in Pasadena, Los Angeles, is in its assembly and testing phase, in advance of a launch scheduled for autumn 2011 and delivery of a rover named Curiosity to Mars in summer 2012.

During the final stage of the spacecraft's arrival at Mars in 2012, a rocket-powered descent stage will lower the rover on a tether directly to the ground. Acoording to JPL, this rover is too big for the airbag- cushioned landing method used by NASA's Mars Pathfinder mission in 1997 and Mars Exploration Rover landings in 2004.

At Mars, a radar on the descent stage will track the spacecraft's decreasing distance from the surface.

JPL said its engineers will conduct more helicopter-flown tests of the radar system to check whether the suspended rover might confuse the radar about the speed of descent toward the ground.

The JPL has confirmed that Wolfe Air Aviation, a company in Pasadena, is providing the helicopter and flight services for the testing.