A flotilla of spacecraft was sent to Mars in 2003 – from Europe, Japan and the USA. NASA launched two craft – Spirit and Opportunity – on the Mars Exploration Rover mission.

Spirit was launched from Cape Canaveral on June 10, 2003, and Opportunity followed on July 7. Among their goals was to study rocks and signs of water.

In January the twin robot rovers landed in different regions of Mars to travel around and explore the terrain. You can see an artist’s impression of one, right.

Spirit came down in the 150 km (95 mile) wide Gusev Crater in the Ma’adim Vallis valley on January 4, 2004. It returned spectacular images before developing a computer fault on January 21. NASA solved the problem, caused by an overload of data.

Opportunity landed on January 25 in the Meridiani Planum region, scoring an interplanetary “hole-in-one” by ending up in a crater 20 meters (66ft) across and not far from another larger crater.

The two rovers’ initial missions were set at 90 days, but they vastly exceeded that and were still operating more than three years later. Opportunity continued exploring in 2007 despite nursing a broken robotic arm. Companion Spirit, in Gusev Crater, was soldiering on with a broken right front wheel which it had to drag through the martian soil. This “failure” actually helped provide one of Spirit’s greatest discoveries – further evidence that the planet was once a very wet place. In late 2007, the robust rovers showed that they had managed to survive one of Mars’s planet-wide dust storms.

Europe’s mission, Mars Express, was launched aboard a Suyuz-Fregat rocket on June 2, 2003, from Rusia’s Baikonur Cosmodrome. Seen in the artist’s impression, right, it arrived at Mars on December 26 and successfully went into orbit around Mars to scan the planet for information about its atmosphere, structure and geology. Days before its arrival, in December 2003, Express jettisoned a British lander called Beagle 2.

This rover, built and run by the Open University, was named after the first Beagle, a ship which carried Charles Darwin on his mission to explore uncharted areas of Earth in 1831. It was intended to look for evidence of water and life but no signal was received from the probe in the hours after it landed and there are fears that it crashed.

Another probe due to arrive at Mars was the Japanese Nozomi (Planet-B) probe which was launched in July 1998 and was described on a previous page. It should have reached Mars in late December 2003 but failed after onboard equipment broke down.

In March 2006, a new NASA probe arrived, Mars Reconnaissance Orbiter, carrying the most powerful camera ever sent to another world. It can record objects as small as a dinner plate and has recorded images of previous Mars probes on the surface, including the two rovers, Spirit and Opportunity. No sign of Beagle 2 was seen, however, in high-resolution pictures of the landing site released in early 2007.

In August, 2007, another NASA spacecraft, the Phoenix Mars Lander, blasted off to begin the biggest ever search for life on Mars. It landed safely in May 2008 and soon began digging into the Red Planet’s icy soil to look for evidence that the planet could ever have supported alien life. The probe, which sent back data for five months before freezing to death, gave us our first close-up pictures of water ice on Mars. You can see it in the enhanced view of a trench dug by Phoenix, right. Catch up on our latest news reports about Phoenix!

The next NASA mission to the Red Planet, Mars Science Laboratory, was due to launch in October 2009 but has been postponed until late 2011 because of delays in testing the complex rover and its experiments.