10 October 1960: The USSR launches an unnamed probe into space, but it fails before even achieving an orbit around Earth.
5 November 1964: Mariner 3 lifts off on the first mission to Mars, to take pictures. It suffers a malfunction and never reaches the Red Planet.
28 November 1964: Mariner 4 starts an eight-month journey to Mars.
In July 1965, Mariner 4 collects the first close-up pictures of another planet.
November 30 1964: Zond 2 becomes the first Soviet craft to get close to Mars, but it does not send back planetary data.
24 February 1969: Mariner 6 sets off to analyse the martian atmosphere and surface with remote sensors, and records. It sends hundreds of images back to Earth.
31 July 1969: Mariner 7 sets off on a mission similar to that of its predecessor.
8 May 1971: Mariner 8, marked to become the first Mars orbiter, fails during launch. But Mariner 9, which leaves 22 days later, becomes the first satellite around Mars. It photomaps all of the planet's surface and takes the first close-up images of Mars' two moons, Phobos and Deimos.
28 May 1971: The Soviet Union launches Mars 3, which sends back the country's first few bits of Mars data and photographs.
20 August 1975: Viking 1 lifts off and, with Viking 2, launched on 9 September, becomes the first craft to land on another planet.
Viking 1 takes photographs and collects other scientific data.
Viking 2 carries out three biology experiments searching for evidence of life. None is found, but scientists discover surprising chemical activity in the martian soil.
25 September 1992: The Mars Observer takes instruments to study Mars' geology, geophysics and climate, only to lose contact with ground control shortly before reaching the planet.
7 November 1996: The Mars Global Surveyor takes off to replace the Mars Observer. It is successful and is still operational today.
16 November 1996: The lift-off of Mars 96, with orbiters and landers, marks Russia's first independent attempt at Mars research, but the launch vehicle fails.
4 December 1996: Mars Pathfinder blasts off and proceeds to put a robotic rover on the surface. About 2.3 billion bits of information are collected and scientists decide that Mars was once warm and wet.
4 July 1998: Japan's first planetary exploration mission begins, though the Nozomi is to travel for five years and never reach Mars' orbit.
11 December 1998: Mars Climate Orbiter, intended to be a weather satellite and communications relay, is destroyed when it enters Mars' atmosphere too low.
3 January 1999: Nasa launches the Mars Polar Lander with Deep Space 2 to probe for ice and test new technologies. They are lost 11 months later.
7 April 2001: Mars Odyssey is launched and is still orbiting
and carrying out experiments on Mars' geology and climate. It aids in the search for evidence of water and life on the Red Planet.
2 June 2003: The European Space Agency's Mars Express orbiter and its lander, Beagle 2, were launched on 2 June 2003. Mars Express will play a key role in an international exploration programme spanning the next two decades.
10 June 2003: Spirit, a robotic geologist, blasts off. With
its sensors and cameras, it is still gathering invaluable
information about the surface of Mars.
7 July 2003: Opportunity, Spirit's robotic partner, sets off.
The two have been studying Mars' geology and climate ever since.
14 January 2004: US President George Bush announces a new Nasa initiative to eventually send humans to Mars via a moon base after 2020.