|One of the robots that will|
unravel Martian mysteries
Originally scheduled for launch on Sunday, NASA (National Aeronautics and Space Administration) announced a delay of 24 hours due to bad weather.
The first Mars Expedition Rover (MER) will now be launched on Monday at 2:02 pm (1802 GMT) from an Air Force base adjacent to the Kennedy Space Centre in Cape Canaveral, Florida.
The launch of the second robot is now scheduled for 2:40 pm (1840 GMT) on Monday, officials said.
The two six-wheeled robots will land on the opposite sides of Mars and go about for three months collecting geological samples.
Powered by solar energy, the robots will be able to move 40 metres each Martian day. The MER robot has a telescopic arm including a camera which will be able to take 360-degree colour images. It also has equipment to scratch and dig into the surface.
A squad of 150 scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, will gather data transmitted by the robots to Earth via two US satellites in orbit around Mars: The Global Surveyor and Odyssey probes.
The robots will first explore the area around their drop points before venturing out 500 metres each over the course of the mission.
To reach Mars, the first robot MER-A will traverse 500 million kilometres over seven months, then drop into the Gusev crater, 15 degrees south of the Martian equator, on 4 January 2004. The second Mars Rover will land on an area of Mars known as the Meridiani Planum.
"This will continue NASA's long goal of finding twater. On Earth, wherever we find water, we find life. There was water on Mars billions of years ago and maybe just a few hours ago," said Ed Weiler, associate administrator for space science for NASA.
The robots use parachutes and air bags to slow down the spacecraft and cushion the impact. Each vessel will bounce about 10 times on the Martian surface before coming to a standstill.
The US MERs will be competing with Europe's Mars Express which was launched on 2 June.
There is no water on Mars in liquid form. But Martian topography indicates there may have been running water on the planet in the past.