The search for water ice on Mars.

The mission has studied the entire Martian surface, atmosphere, and interior, and has returned more data about the red planet than all other Mars missions combined. Also in 1996 the United States launched a lander and rover called Mars Pathfinder. Mars Pathfinder was originally designed to deliver an instrumented lander and a free-ranging robotic rover to the surface of the red planet. .
             Mars Pathfinder used an innovative method of directly entering the Martian atmosphere, assisted by a parachute to slow its descent through the thin Martian atmosphere and a giant system of airbags to cushion the impact. From landing until the final data transmission on September 27, 1997, Mars Pathfinder returned 2.3 billion bits of information, including more than 16,500 images from the lander and 550 images from the rover, as well as more than 15 chemical analyses of rocks and soil and extensive data on winds and other weather factors.
             In 1998 the United States launched the Mars Climate Orbiter. The orbiter was designed to function as an interplanetary satellite and communication relay for the Mars Polar Lander. Unfortunately it was lost during arrival in 1999. In 1999 the United States launched the Mars Polar Lander/Deep Space 2. Piggybacking on the lander were two small probes called Deep Space 2 designed to impact the Martian surface to test new technologies. Mars Polar Lander and Deep Space 2 were lost at arrival in 1999.
             In 2001 the United States launched the Mars Odyssey it is an orbiting spacecraft designed to determine the composition of the planet's surface, to detect water and shallow buried ice, and to study the radiation environment. .
             The Odyssey will collect images that will be used to identify the minerals present in the soils and rocks on the surface and to study small-scale geologic processes and landing site characteristics. By measuring the amount of hydrogen in the upper meter of soil across the whole planet, the spacecraft will help us understand how much water may be available for future exploration, as well as give us clues about the planet's climate history.