Space missions

Unmanned space missions are those using remote-controlled spacecraft.
The first such mission was the Sputnik I mission, launched October 4, 1957. Some missions are more appropriate for unmanned missions rather than manned space missions, due to lower cost and lower risk factors.
Since the early 1970s, most unmanned space missions have been based on space probes with built-in mission computers, and as such may be classified as embedded systems.
Most American unmanned missions have been synchronized by the Jet Propulsion Laboratory, and European missions by the European Space Operations Centre, part of ESA (the European Space Agency).
ESA has conducted comparatively few space exploration missions. ESA has, however, launched a variety of spacecraft to carry out astronomy, and is a collaborator with NASA on the Hubble Space Telescope.
There has been a large number of very successful Russian space missions. There were also a few Japanese and Chinese missions.