Backgrounder: NASA's historical Mars exploration missions
WASHINGTON, May 25 (Xinhua) -- NASA's latest Mars exploration spacecraft the Phoenix Lander is set to touch down in the Mars arctic region on Sunday. The following is a brief introduction to NASA's past Mars missions:
1964, November, Mariner 3: failed to jettison its shroud after launch.
1964, November, Mariner 4: made first successful Mars flyby in July 1965 and returned 21 photos.
1969, February, Mariner 6: flied past Mars in July 1969 and returned 75 photos.
1969, March, Mariner 7: flied past Mars in August 1969 and returned 126 photos.
1971, May, Mariner 8: this Mars orbiter failed during launch.
1971, May, Mariner 9: this following orbiter successfully reached Mars orbit in November 1971, and operated till October in 1972. It returned 7,329 photos to Earth.
1975, August, Viking 1: The complex of Mars orbiter and lander arrived at Mars orbit in June 1976. The lander touched down on Mars in July 1976. Orbiter operated till 1980, and lander till 1982.
1975, September, Viking 2: The second complex of Mars orbiter and lander arrived at Mars orbit in August 1976. The lander touched down in September 1976. Orbiter operated till 1987, and lander till 1980.
Combined, the Viking orbiters and landers returned more than 50,000 photos.
1992, September, Mars Observer: lost just before Mars arrival in August 1993.
1996, November, Mars Global Surveyor: this Mars orbiter arrived at Mars orbit in September 1997, conducted a high-detail mapping to Mars, and the last communication to Earth occurred in November 2006.
1996, December, Mars Pathfinder: A complex of Mars lander and rover landed in July 1997, and last transmission occurred in September 1997.
1998, December, Mars Climate Orbiter: lost upon arrival in September 1999.
1999, January, Mars Polar Lander with Deep Space 2 microprobes: the lander and two probes lost just on arrival in December 1999.
2001, March, Mars Odyssey: the orbiter arrived at Mars orbit in October 2001, currently conducting extended science mission and providing relay for Mars Exploration Rovers.
2003, June, Mars Exploration Rover Spirit: landed in January 2004 for three-month prime mission inside Gusev Crater, currently conducting extended mission.
2003, July, Mars Exploration Rover Opportunity: landed following Spirit in January 2004 for three-month prime mission in Meridiani Planum region, currently conducting extended mission.
2005, August, Mars Reconnaissance Orbiter: began orbiting in March 2006, currently conducting primary science phase; has provided data that include more than 25,000 images and 3,500 radar observations. The mission has returned more total data than produced by all previous Mars missions combined.