Friday, December 11, 1998 Published at 23:49 GMT
Rain check on Mars
Nasa's Mars Climate Orbiter left bang on time
A space probe that will orbit Mars looking for water and watching the weather has been launched from Cape Canaveral.
Mars is known to have water, some of it in the form of ice, and scientists believe this may have made it conducive to life.
However, no one knows where all its water is, and scientists are hoping the probe will find out.
A second probe - to be launched from Florida in January - will land on the surface, carrying a microphone to record the sound of wind from the Red Planet.
The orbiter's interplanetary trek began with separation from the rocket's third stage about 47 minutes into flight, high above the Indian Ocean.
"The Climate Orbiter is en route to Mars," said Nasa launch commentator Bruce Buckingham after a tracking station in Perth, Australia, confirmed the probe was on its way.
The 1,387 lb probe is due to arrive at Mars next September after a 416-million mile voyage.
For six months the craft will gently lower its orbit by skimming the planet's upper atmosphere about 200 times to slow its speed.
Instruments will keep tabs on the Martian weather, track wispy clouds in the dusty atmosphere and examine the rock-strewn, rust-coloured surface.
The orbiter will also serve as a communications relay for a second Mars probe, scheduled for launch on 3 January.
That probe should touch down near the icy Martian north pole and analyse soil samples scooped up with a robotic arm.
The twin Mars missions, which cost about $328m, are part of a 10-year effort to determine if life existed or still survives on the planet.
The first two probes in the series, the Mars Pathfinder lander and the Mars Global Surveyor orbiter, were launched in 1996.
"The key is the water," said Ed Weiler, Nasa's head of space science.
"Follow the water. And that is what these two missions do. They really try to understand the current situation with water on Mars.