The Mars Global Surveyor launched on November 7, 1996. It traveled towards Mars for 309 days, entering orbit on September 12, 1997.
Starting in March, 1998, MGS started making pole-to-pole observations of
the planet. Its
goal is to map the entire Martian globe, laying the foundation for 10 more
years of NASA missions. Global Surveyor's role is to determine the geology
and perhaps the past history of Mars and its climate. It is designed to
compile global maps of Mars and collect data on its atmosphere, surface
composition, interior and evolution.
||MOLA, the Mars Orbiter Laser Altimeter, is an instrument on the Mars Global
Surveyor spacecraft. It collected altimetry data about the height
of surface features on Mars until June 30, 2001.|
The altitude determination process used by MOLA works by measuring the time
that a pulse of light takes to leave the spacecraft, reflect off of the
surface of Mars, and return to MOLA's collecting mirror. By multiplying
the reflection time by the speed of light, scientists can calculate
Surveyor's altitude above the local terrain to within 30 meters (98 feet)
As the spacecraft flies above hills, valleys, craters, and other surface
features, its altitude above the ground constantly changes. A
combination of MOLA data with images from the camera will allow scientists
to construct a detailed topographical atlas of the planet. Such maps will
help in the understanding of the geological forces that shaped Mars.
Of the many important discoveries made using MOLA data, 10 are discussed
on our MOLA Discoveries page.