The Mars Science Laboratory (MSL) rover "Curiosity" landed in Gale crater on 6 August 2012 UT to begin a mission to investigate the habitability of an ancient aqueous sedimentary environment on Mars. MSL carries a comprehensive payload of remote sensing and in-situ instruments designed to characterize the geology, elemental composition, mineralogy, and geochemistry of materials encountered on Mars.
The Probe will also examine the strata of the mountain nearby Gale Crater, Aeolis Mons.
Using its battery of scientific instruments it may uncover evidence for past habitability, investigating the possible origins of life on Mars, and Earth and ultimately paving the way for possible human habitation of the planet.
The Mission requires navigation in space and on Mars that has never been done before, an entry of the largest robotic payload to Mars in history, navigation between 2 spacecraft during the 7 minute approach to the Martian surface, using radar to activate retrorockets (an important development for any manned mission to the planet) and automatic preparation of the probe wheels before landing. It is important to stress that many things could go wrong in this mission, it is also the most significant space mission in 8 years as it will undoubtedly allow for the best preparation for a human mission to the red planet.
The Curiosity Rover is an incredibly interesting piece of technology, not least for its arm-drill, spectroscopic chemistry equipment and laser vaporiser but what fascinates me is its power source.
This robotic laboratory's power source is just like the Galileo, Pioneer and Voyager spacecraft and like the successful Viking 1 and Viking 2 Mars landers in 1976: The robot has a tiny nuclear reactor quarantined in a separate thermoelectric generator inside the vehicle, a radioisotope thermoelectric generator (RTG).
Since Plutonium has a half-life of ~24,400 years, this robot will be probably still operational when the first humans arrive on Mars.
The rover's Plutonium battery contains 4.8 kg (11 lb) of plutonium-238 dioxide supplied by the U.S. Department of Energy, packed in 32 pellets each about the size and shape of a marshmallow.
The success of the mission also requires a rendezvous with another spacecraft, the Mars Reconnaissance Orbiter.
Basic radio-frequency tones that go directly to Earth and more complex UHF radio data require relaying by Martian orbiters.
NASA's Mars Reconnaissance Orbiter will record the UHF data and send it back to Earth. NASA's Odyssey orbiter will also play a role in the mission, and will pick up the UHF signals from the lander and relay it immediately back to Earth, this will give the first pictures of Gale Crater taken from the surface.