Mars Global Surveyor

Technicians at the Jet Propulsion Laboratory fitting the Mars Global Surveyor spacecraft in a protective canister for its transfer from the payload hazardous servicing facility (PHSF) to the launch pad.

The Mars Global Surveyor (MGS) arrived at Mars after a ten-month flight from Earth. MGS used the planet's atmosphere to decrease its speed (aerobraking), so that it could be captured by Martian gravity into a 45-hour circular orbit.

The periapsis and apoapsis of the Mars Global Surveyor (MGS) as it orbits Mars. MGS changes its orbits by aerobraking at each orbit's periapsis.

US spacecraft, launched in November 1996, that went into orbit around Mars in September 1997 to conduct a detailed photographic survey of the planet, commencing in March 1998. The spacecraft used a previously untried technique called aerobraking to turn its initially highly elongated orbit into a 400 km/249 mi circular orbit by dipping into the outer atmosphere of the planet. The Global Surveyor established its correct orbit for mapping the surface of Mars in February 1999, a year later than planned.

In June 2000, US astronomers announced that photographs from the Mars Global Surveyor showed channels that seemed to have been formed by large amounts of water seeping to the surface and causing landslides. Around 65,000 images taken in the previous year were examined, and were thought to be evidence of a ground-water supply. In 2001, the Global Surveyor located two regions on the surface rich in haematite, providing further evidence for the existence of water at some time in the planet's history. On 31 January 2001, Mars Global Surveyor completed its primary mission and then went into an extended mission phase, continuing to transmit data back to Earth.