With the recent successful landing of the Phoenix Mars probe, the high failure rate of such probes is once more highlighted.

Nearly 50 percent of all the missions to Mars since 1960 ended in failure, with some never even making it to Mars, while others disappeared without a trace.

Here is a chronology of the main events in the exploration of the Red Planet.

1960-64: The USSR fails at six tries to send probes to Mars, and the United States’ first try, in November 1964, also fails.

July 1965: The US probe Mariner 4 collects the first close-up pictures of another planet on a flyby of Mars.

Nov. 30, 1964: The USSR’s Zond gets close to Mars in a flyby but does not send back any data.

Feb-Mar 1969: The US launches Mariner 6 and Mariner 7 carrying sensors to analyse the Martian atmosphere and surface, and they send back nearly 200 pictures of the northern and southern polar caps and the moon Phobos.

May 31, 1971: Mariner 9 launches to become the first successful orbiter of Mars, photomapping all of the planet’s surface and taking close-up images of Phobos and Deimos, Mars’ second moon.

May 1971: The USSR launches twin orbit vehicles Mars 2 and 3, which both successfully go into orbit around the planet. But the surface rovers they deployed fail, as do two more landers in March 1974.

July-Sept 1976: The US places two landers on Mars from the Viking 1 and 2 orbiters. The Viking 2 lander’s biology experiments fail to find evidence of life, but reveal surprising chemical activity in the Martian soil.

Sept. 11, 1997: The US Mars Global Surveyor goes into orbit around Mars, and over nine years tracks changes in the planet’s surface including evidence of modern water flows and seasonal shifts.

July 4, 1997: The US Mars Pathfinder lands on the rocky Ares Vallis region of Mars. Its lander and rover return more than 17 000 images and extensive data on soil and rock composition and wind and other weather factors. The data suggests Mars was formerly warm and wet, with a more dense atmosphere and liquid water.

July 4, 1998: Japan enters the Mars exploration race, but its Nozomi probe never reaches Mars’s orbit.

April 7, 2001: The US Mars Odyssey orbiter is launched to carry out experiments on Mars’s geology and climate, aiding the search for evidence of water and life.

June 2, 2003: European Space Agency launches Mars Express, carrying the British-built Beagle 2 lander. The lander loses contact upon separating from the orbiter in Dec 2003, its fate unknown.

Jan 2004: The US places rovers Spirit and Opportunity on opposite sides of Mars to undertake extensive geological analysis of the surface.

Jan 14, 2004: US President George W. Bush announces a new NASA initiative to eventually send humans to Mars via a moon base after 2020.

Feb 25, 2007: European Space Agency’s Rosetta spacecraft performs a risky low-altitude flyby of Mars.

May 25, 2008: The US Mars Phoenix Lander successfully touches down in the planet’s north pole region.