
An artist's interpretation of the
MESSENGER spacecraft at Mercury
A 'robotic spacecraft' is a
spacecraft with no humans on board, that is usually under
telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a
space probe. Many space missions are more suited to telerobotic rather than
crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as
Venus or the vicinity of
Jupiter are too hostile for human survival, given current technology. Outer planets such as
Saturn,
Uranus, and
Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are the only way to explore them.
Many artificial
satellites are robotic spacecraft, as are many
landers and
rovers.
Control
Robotic spacecraft use
telemetry to radio back to Earth acquired data and vehicle status information. Although generally referred to as "remotely-controlled" or "telerobotic", the earliest orbital spacecraft -- such as
Sputnik 1 and
Explorer I -- did not receive control signals from Earth. Soon after these first spacecraft, command systems were developed to allow remote control from the ground. Increased
autonomy is important for distant probes where the light travel time prevents rapid decision and control from Earth. Newer probes such as
Cassini-Huygens and the
Mars Exploration Rovers are highly autonomous and use on-board computers to operate independently for extended periods of time.
History
The first space mission, Sputnik 1, was an artificial satellite put into Earth orbit by the Soviet Union on 4 October 1957. On 3 November 1957, the Soviets orbited
Sputnik 2, the first to carry a living animal into space –
a dog.
The United States achieved its first successful space probe launch with the orbit of Explorer I on 31 January 1958. Explorer I was about the size of a grapefruit and weighed less than 14 kilograms compared to 83.6 kg and 508.3 kg for Sputniks 1 and 2 respectively. Nonetheless, Explorer I confirmed the existence of the
Van Allen belts, a major scientific discovery at the time.
Only six other countries have successfully launched missions using their own vehicles: France (1965), Japan (1970), China (1970), the United Kingdom (1971), India (1981) and Israel (1988).
Most
American space probe missions have been coordinated by the
Jet Propulsion Laboratory, and European missions by the
European Space Operations Centre, part of the
European Space Agency (ESA). ESA has conducted relatively fewer
space exploration missions in the past (one example is the
Giotto mission, which encountered
comet Halley), but have launched several interplanetary spacecraft in recent years (e.g.
Rosetta space probe,
Mars Express,
Venus Express). ESA has, however, launched many spacecraft to carry out
astronomy, and is a collaborator with
NASA on the
Hubble Space Telescope. There have been many successful
Russian space missions. There have also been a few Japanese, Chinese and
Indian missions.
List of space probes
:''This is a condensed version of the more detailed
List of planetary probes.''
Lunar probes
★
Luna program — Soviet Lunar exploration (1959–1976).
★
Ranger program — US Lunar hard-landing probes (1961–1965).
★
Zond program — Soviet Lunar exploration (1964–1970).
★
Surveyor program — US Lunar soft-landing probe (1966–1968).
★
Lunar Orbiter program — US Lunar orbital (1966–1967).
★
Lunokhod program — Soviet
Lunar Rover probes (1970–1973).
★
Muses-A mission (''
Hiten'' and ''
Hagoromo'') — Japanese Lunar orbital and hard-landing probes (1990–1993).
★ ''
Clementine'' — US Lunar orbital (1998).
★ ''
Lunar Prospector'' — US Lunar orbital (1998–1999).
★ ''
Smart 1'' — European Lunar orbital (2003).
★ ''
SELENE'' — Japanese lunar orbiter and lander, launch postponed to 2007.
Mars probes
★
Zond program — failed Soviet flyby probe
★
Mars probe program — Soviet orbiters and landers
★
Viking program — Two US orbiters and landers (1974)
★
Phobos program — Failed Soviet orbiters and
Phobos landers
★ ''
Mars Pathfinder'' — Lander and wheeled robot (1997)
★
Mars Surveyor '98 program (''
Mars Climate Orbiter'' and ''
Mars Polar Lander'') — Failed US probes
★
Mars Global Surveyor - US Orbiter
★
Mars Odyssey — US orbiter
★
Mars Observer — failed US Mars orbiter
★
Mars Express (''
Mars Express Orbiter'' and ''
Beagle 2'') — European orbiter and failed lander 2003
★
Mars Exploration Rovers — US rovers (2004)
★ ''
Mars Reconnaissance Orbiter'' — US, launched 2005
★ ''
Phoenix'' — launched August 3, 2007
★ ''
Mars Science Laboratory'' — US, to be launched 2009
General solar system probes
★
Venera program — Soviet
Venus orbiter and lander
★
Vega program — Soviet mission to
Venus and
Comet Halley
★
Zond program — Soviet flyby missions to the
Moon,
Venus, and
Mars
★
Pioneer Venus project — US
Venus orbiter
★
Mariner program — US
Mercury, Venus and
Mars flybys
★
Pioneer program — US
Jupiter and
Saturn flybys
★
Voyager program — US Jupiter, Saturn,
Uranus and
Neptune flyby and study of
interstellar space
★
Giotto mission — European flyby of
Comet Halley (1986)
★
Sakigake probe — Japanese flyby of
Comet Halley (1986)
★
Suisei probe — Japanese flyby of
Comet Halley (1986)
★
Galileo probe — US Jupiter orbiter and atmosphere probe
★
Magellan probe — US Venus orbiter
★ ''
Cassini-Huygens'' — US-European Saturn orbiter and
Titan lander Huygens (1997–present)
★ ''
NEAR Shoemaker'' — US asteroid lander, launched 1996
★ ''
Deep Space 1'' — US comet/asteroid flyby, 1998–2000
★
Stardust probe — US comet flyby and sample return, launched 1999, returned January 15, 2006
★
Genesis — first solar wind sample return mission, 2001–2004 (crash)
★ ''
CONTOUR'' — US comet flyby mission; launch failure in 2003
★ ''
Hayabusa'' — Japanese asteroid orbiter, lander and sample return, launched 2003
★ ''
Rosetta'' — European comet orbiter and lander (
Philae); launched 2004
★
MESSENGER — US Mercury orbiter, launched 2004
★
Deep Impact — successful US comet impactor, launched 2005
★
Venus Express — ESA probe to be sent for the observation of the Venus's weather in 2005.
★ ''
New Horizons'' — launched on
January 19,
2006, it will be the first probe to visit Pluto (in July 2015)
★ ''
Interstellar Boundary Explorer'' (IBEX), scheduled to launch in the summer of 2008.
See also
★
Unmanned resupply spacecraft
★
Geosynchronous satellite
★
Landings on other planets
★
List of planetary probes
★
List of unmanned spacecraft by program
★
Manned space mission
★
Satellite
★
Space exploration
★
Space observatory
★
Timeline of artificial satellites and space probes
★
Timeline of first orbital launches by nationality
★
Timeline of planetary exploration
External links
★
NASA Jet Propulsion Laboratory
★
Russia's unmanned moon missions