Viking 1 Orbiter
The Viking mission
consisted of launches of two separate spacecrafts to
Mars, Viking 1, launched on 20 August 1975, and Viking 2, launched on 9 September 1975,
with the purpose of conducting specific experiments. Each
spacecraft consisted of an orbiter and a lander; the orbiter
mission and the lander image. After orbiting Mars and returning images used for landing site selection, the orbiter and
lander detached and the lander entered the martian atmosphere and soft-landed at the
selected site. The orbiters continued imaging and other scientific operations from orbit
while the landers deployed instruments on the surface.
The fully fueled orbiter-lander pair had a mass of 3527 kg. After separation and landing,
the lander had a mass of about 600 kg and the orbiter 900 kg.