The Nasa mission is expected to reveal new information about the planet's composition, the presence of water and even what noises can be heard on its surface.
The unmanned craft, named the Mars Polar Lander, was due to lift off last night on the back of a Delta 2 rocket. But there was concern that the launch would be delayed because of a rough weather.
Nasa has 25 days to send the probe on its way, to take advantage of a beneficial alignment of the Earth and Mars. Last month the agency successfully launched the Mars Climate Orbiter, which is designed to circle Mars and scan its surface from a height of 262 miles.
The Lander is scheduled to reach Mars in December after a journey of 416 million miles and touch down close to the planet's permanent ice cap at the southern pole. The craft is equipped with a mechanical arm to scoop up soil and a camera to survey the landing area.
A microphone will allow Nasa scientists for the first time to listen in to wind sounds or any other noises audible on the planet.