|
The Mariner missions (1964-1971) photographed the surface of Mars, studied the Martian atmosphere,
discovered Olympus Mons and Vallis Marineris, photographed the Martian moons, disproved the theory
that the surface of Mars was scarred by artificial canals, and returned evidence of surface water.
During the mid-1970s, the Viking missions
explored Mars with both orbiting spacecraft and landers.
Viking transmitted images of the surface, took surface samples and analyzed them for composition and
signs of life, studied atmospheric composition and Martian meteorology, and deployed seismometers.
While the Viking landers did not find evidence of life, many scientists have remained optomistic that such
evidence would eventually be found.
In the near future, NASA plans to launch four robotic Mars missions: Mars Global Surveyor (scheduled for Nov. 1996),
Mars Pathfinder (scheduled for Dec. 1996), Mars Surveyor '98 Orbiter, and Mars Surveyor '98 lander.
Long-term plans call for a Mars sample return mission and, perhaps around the year 2018, a human mission to
the Red Planet.
|
