Exploration of Mars

The exploration of Mars has taken place over hundreds of years, beginning in earnest with the invention and development of the telescope since the 1600s. Increasingly detailed views of the planet from Earth inspired speculation about its environment and possible life – even intelligent civilizations – that might be found there. Probes sent from Earth beginning in the late 20th century have yielded a dramatic increase in knowledge about the Martian system, focused primarily on understanding its geology and possible habitability potential.

Engineering interplanetary journeys is very complicated, so the exploration of Mars has experienced a high failure rate, especially in earlier attempts. Roughly two-thirds of all spacecraft destined for Mars failed before completing their missions, and there are some that failed before their observations could begin. However, missions have also met with unexpected levels of success, such as the twin Mars Exploration Rovers operating for years beyond their original mission specifications.

Since 6 August 2012, there have been two rovers on the surface of Mars beaming signals back to Earth (Opportunity, and Curiosity of the Mars Science Laboratory mission), and three orbiters currently surveying the planet: Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter.

To date, no sample return missions have been attempted for Mars, and one attempted return mission for Mars' moon Phobos (Fobos-Grunt) has failed.