The Mars Global Surveyor (MGS) was an orbiter sent to explore Mars and send back information about how the Martian climate and landscape have been changing over time. It was launched by NASA from Cape Canaveral on November 7, 1996, on a Delta-7925 rocket, and arrived at Mars on September 11, 1997. It had actually been built using many spare parts from the failed Mars Observer mission. There was initial concern that the fate of MGS was doomed as well, when one of its two solar panels did not deploy properly after launch.

Using the pioneering method of “aerobraking”—adjusting and slowing the spacecraft’s orbit by flying it through the top of the Martian atmosphere—MGS was gently placed into a nearly circular orbit over the course of more than a year. MGS began mapping the surface of the Red Planet in March 1999. By carefully managing its fuel and electrical energy supply, scientists were able to extend the life of MGS more than five years beyond its primary mission. The Mars Global Surveyor was lost in November 2006, after taking more pictures than all other Mars missions that preceded it.