Sunday, January 3, 1999 Published at 22:00 GMT
Mars mission beats the weather
Dramatic pitcures were beamed back from the Delta 2 rocket
The Mars Polar Lander blasted off on schedule despite bad weather which threatened to delay the mission to test for signs of water and life on the Red Planet.
With America's Mid-west gripped by some of the worst snow storms this century, launch officials were concerned that strong thunderstorms and an approaching cold front at the time of launch gave them only a 30-40% chance of a take-off.
The programme began with the groundbreaking Pathfinder mission of 1996 which sent back vivid pictures of the planet's barren surface.
Mapping the planet
Three months later, Mars Global Surveyor began to map the planet from orbit.
The purpose of the mission says Edward Stone, Director of the Jet Propulsion Laboratory, is "to understand the geology of Mars and if there is still water, or at least ice, in the soil of Mars".
Scientists hope that two additional missions planned every two years will lead to a manned voyage to Mars as early as 2015.
Water is the key
"On Earth, wherever there is liquid water we find life," says the Jet Propulsion Laboratory's Edward Stone. "So one of the keys to searching for evidence of past or possible current life is to look for where there was water, or where there is water."
After its 416 million mile journey, the Lander will enter the upper reaches of the Martian atmosphere in December travelling at a break-neck 6.8km per second (15,400 mph). By the time it reaches the surface, it should be travelling at a more stately 2.5 meters per second (5.4 mph).
Shortly before touch-down it will eject two mini-probes known as Deep Space 2 that will stab into the Martian surface to analyse soil samples.
The Lander itself is equipped with a robotic arm that will collect samples of soil for testing in small ovens to check for signs of water and other gases.
Overall the probe is expected to operate for between 60 and 90 Martian days (One Martian day = 24 hours 37 minutes) through the southern summer, before the onset of winter reduces the light reaching its solar panels.