Key Dates:
- 11.07.96: Launch (17:00:49 UT)
- 09.11.97: Arrival at Mars
- 11.05.06: Contact Lost
- Status: Orbiting Mars
Scientific Instruments:
- MOC Mars orbital camera
- MOLA Mars orbital laser altimeter
- TES thermal emission spectrometer
- MAG/ER magnetometer/electron reflectometer
- RS radio science experiment
- MR Mars relay antenna for future spacecraft
Mars Global Surveyor Mission Information: Mars Global Surveyor was the first successful mission to the Red Planet in two decades. The Mars Global Surveyor (MGS) was designed to orbit Mars over a two year period and collect data on the surface morphology, topography, composition, gravity, atmospheric dynamics, and magnetic field. This data will be used to investigate the surface processes, geology, distribution of material, internal properties, evolution of the magnetic field, and the weather and climate of Mars.
After launch on a Delta 7925 (a Delta II Lite launch vehicle with nine strap-on solid-rocket boosters and a Star 48 (PAM-D) third stage) and a 10 month cruise phase, the Mars Global Surveyor was inserted into an elliptical capture orbit at 01:17 UT 12 September 1997. Over the next four months, it was intended that aerobraking maneuvers and thrusters would be used to lower the orbit to the final circular mapping orbit. However, one of the solar panels failed to latch properly when it was deployed and subsequently showed unexpected motion and moved past its fully deployed position when aerobraking began (thought to be due to the fracture of a damper arm and subsequent structural damage). A new aerobraking schedule was employed, which involved slower aerobraking putting less pressure on the solar panels through April 1998, at which time an 11.6 hour science phasing orbit with a 171 km periapsis was achieved and aerobraking was halted. After a 5 month hiatus, aerobraking was resumed on 23 September 1998. Science observations were made periodically during these maneuvers.
After aerobraking ended in February 1999, MGS was in a 118 minute circular polar science mapping orbit with an index altitude of 378 km. The orbit is sun-synchronous (2 a.m./2 p.m.) and maps over the 2 p.m. crossing from south to north (instead of north to south as originally planned). The orbit has a 7 day near-repeat cycle so Mars will be mapped in 26 day cycles. Science mapping began in mid-March 1999, which was summer in the northern hemisphere on Mars. The primary mission was planned to last one martian year (687 Earth days) through January, 2001. An extended mission was to continue until April 2002. After this time, the orbiter was to act as a relay until January 2003 in support of the other missions of the Mars Surveyor program. Operations were expected to end by 31 January 2001, but the good health of onboard systems allowed scientists to continue the mission.
Contact with Mars Global Surveyor has been lost since 5 November, 2006, ground operators are trying to determine what caused the loss of communication.
