All is set for one of the most ambitious space missions ever devised.Nasa is about to launch its latest Mars rover, nicknamed Curiosity, from Cape Canaveral, Florida.At nearly a tonne, the six-wheeled vehicle dwarfs all previous robots sent to the surface of the planet.The machine carries a suite of sophisticated instruments and tools, including a hammer drill and a laser, to find out whether Mars is, or ever has been, suitable for life.The US space agency will get its first opportunity to launch the robot - also known as the Mars Science Laboratory (MSL) - at 10:02 local time (15:02 GMT) on Saturday.Weather conditions look good on the Space Coast and engineers report no technical issues after replacing a suspect battery in Curiosity\'s Atlas 5 launch rocket earlier in the week.Lift-off is just the start for what Nasa hopes will be a multi-year campaign at the Red Planet.The rover is equipped with a plutonium battery and so should have ample power to keep rolling for more than a decade. It is likely the mechanisms on MSL will wear out long before its energy supply.\"MSL is an incredibly important flagship mission for this agency… as important as Hubble,\" observed Doug McCuistion, Nasa\'s Mars exploration programme director.The organisation has certainly invested a huge amount of money in the project (costed at $2.5bn/£1.6bn), and has had to bear a barrage of criticism for delays and budget overruns.But Nasa believes the memory of past woes will quickly fade when this exciting mission reaches the surface of Mars in eight-and-a-half-months\' time. That is how long the robot will take to cover the 570-million-km cruise distance to the Red Planet after Saturday\'s launch.