Exploration of the Solar System
The following table provides a list of the various missions, past, present and future, sent to explore our local neighborhood. A brief description of each mission, along with the relevant web links is presented after the table. Operating missions are highlighted in boldface, missions in development (funded, hardware under construction) are italicized. Missions under study but not yet funded are indicated with a following ?. Capitalized names refer to acronyms, e.g., NEAR, which is NASA-speak for the Near Earth Asteroid Rendezvous mission. Missions are grouped in order of increasing complexity. Reconnaissance means an initial inspection, which, for planetary exploration, implies a fly-by mission. Survey missions involve entering orbit around the object and conducting a detailed investigation. Exploration implies a landing or in situ investigation (e.g., an atmosphere probe). Some missions include elements of both of the latter mission types. This approach to classifying missions is naturally also a time sequence of exploration; the less complex fly-by missions are attempted first, followed by more sophisticated survey and exploration missions.
Object / Reconnaissance / Survey / ExplorationMoon / Ranger / Lunar Orbiter / Surveyor
Lunar Prospector / Lunakhod
SMART-1
/ ApolloLunar-A
/ Lunar-ASelene
Mercury / Mariner 10 /Messenger
BepiColombo
Venus / Mariner 2 / Pioneer Venus / Venera 7,9,14Mariner 10 / Magellan / Pioneer Venus
Venus Express
Mars / Mariner 4 / Mariner 9 / Viking 1,2 LandersMariner 6,7 / Viking 1,2 Orbiters / Pathfinder
Mars Global Surveyor
/Mars Exploration Rovers
Mars 2001 Odyssey
/Beagle 2
Mars Express
Mars Recon Orbiter
/Phoenix
Jupiter / Pioneer 10,11 / Galileo / Galileo ProbeVoyager 1,2 / JIMO ?
Saturn / Pioneer 10,11 /
Cassini
/Huygens Probe
Voyager 1,2
Uranus /Voyager 2
Neptune /Voyager 2
Pluto /New Horizons
Asteroids / Galileo / NEAR /Hayabusa
Deep Space 1 /Dawn
Comets / Giotto /Rosetta
/Stardust
Deep Space 1 / /Rosetta
Deep Impact
Here are especially useful web sites containing detailed information about planetary missions:
4 solarsystem.nasa.gov/missions/ {solar system missions, links to past, current & future probes}
4 science.hq.nasa.gov/missions/phase.html {All space science missions, including astrophysics, planetary science, and space physics}
4 discovery.nasa.gov {NASA's Discovery Program}
4 www.jpl.nasa.gov {Jet Propulsion Lab's homepage}
4 nssdc.gsfc.nasa.gov/planetary/ {NASA's data archive}
Mercury:
Messenger - messenger.jhuapl.edu/
In July 1999 Messenger was selected as the 7th mission in NASA's Discovery program. It will become the first spacecraft to enter orbit around Mercury. Messenger was successfully launched in July 2004; it will arrive in orbit around Mercury in September 2009.
Mariner 10 - pds.jpl.nasa.gov/planets/welcome/m10.htm
Mariner 10 made three fly-bys of Mercury in 1974-1975, and provided close-up images of about half the planet.
Venus:
Magellan - www.jpl.nasa.gov/magellan/ and pds.jpl.nasa.gov/planets/welcome/magellan.htm
A radar-mapping mission conducted in the early 90s. Magellan provided a detailed global map of Venus using a powerful radar to see through the cloud layers.
Pioneer Venus - nssdc.gsfc.nasa.gov/planetary/pioneer venus.html
The Pioneer Venus mission consisted of two components, launched separately: an orbiter and a multiprobe. The orbiter reached Venus in Dec 1978 and provided the first detailed radar maps of the surface. The probes measured atmospheric properties during descent, and one probe lasted for about an hour after impact.
Mariner 10 - pds.jpl.nasa.gov/planets/welcome/m10.htm
Mariner 10 flew by Venus in 1974.
Venera - nssdc.gsfc.nasa.gov/planetary/venera.html
A series of Soviet space probes sent to Venus between 1967 and 1983. These probes both orbited and landed on the surface, returning the first and only photos from the Venusian surface. Venera 7 was the first probe to return data from the surface of another planet.
The Moon:
Lunar Prospector - lunar.arc.nasa.gov/
The third Discovery program mission, Lunar Prospector was launched to a lunar polar orbit in January 1998. It mapped the entire surface, to determine the elemental composition of the lunar crust, and search for the presence of ice in shadowed craters at the lunar poles. The spacecraft was intentionally crashed into the Moon in July 1999 in an (unsuccessful) attempt to vaporize possible ice deposits in one of those craters.
Surveyor - www.jpl.nasa.gov/missions/surveyor/
A series of five spacecraft which soft-landed on the Moon between 1966-1968, prior to the manned Apollo landings.
Ranger - www.jpl.nasa.gov/missions/ranger/
First spacecraft sent towards the Moon from 1961 to 1965. Ranger provided close-up images before impacting on the surface.
Mars:
Mars Exploration Rovers - marsrovers.nasa.gov/home/index.html
Launched in 2003, two “next-generation" Mars rovers reached the red planet in January 2004. Designed to trek about 100 meters each Martian day, the twin robotic explorers continue to send back spectacular images, as well as valuable data on the structure and chemistry of the martian soils & rocks which they encounter.
Mars Express - www.sci.esa.int/marsexpress/
European Space Agency mission, launched in June 2003. This mission consists of an orbiter and a small lander, named Beagle 2. The lander failed to reestablish contact after reaching the surface, and probably crashed.
2001 Mars Odyssey - mars.jpl.nasa.gov/2001/new/index.html
Launched 07 Apr 2001, reached Mars orbit 24-Oct-2001. The orbiter will study surface mineralogy and measure the amount of hydrogen in the shallow sub-surface of Mars, which will provide clues about the presence of water, either past or present.
Mars Climate Orbiter - mars.jpl.nasa.gov/msp98/orbiter/
Part of the Mars Surveyor 98 mission. Launched in Dec 1998; lost at Mars orbit insertion, 23 Sept 99. Inaccurate targeting caused the spacecraft to burn up in the Martian atmosphere.
Mars Polar Lander { mars.jpl.nasa.gov/msp98/index.html
Part of the Mars Surveyor 98 mission. Launched in January 1999, lost 03 December 1999 during descent to the surface. Possibly a software glitch in the main engine or perhaps landed on a soft sand+ice mixture andtoppled over.
Mars Global Surveyor - mars.jpl.nasa.gov/mgs/
Reached Mars in Sept 1997, used extensive aerobraking to achieve the desired orbit. As of 01/05 MGS continues to conduct an imaging and altitude survey of the entire planet and is also providing data on the composition and magnetic properties of the surface.
Mars Pathfinder - mpfwww.jpl.nasa.gov/MPF/default.html
Landed on Mars 04 July 97; tested several new lander technologies; deployed a Mars rover for the first time.
Viking 1 & 2 - nssdc.gsfc.nasa.gov/planetary/viking.html
First successful soft landing on Mars. NASA's Viking Mission to Mars included two spacecraft, each consisting of an orbiter and a lander. The primary mission objectives were to obtain high-resolution images of the surface, determine the structure and composition of the atmosphere and surface, and search for evidence of life.
Mariner 9 - www.jpl.nasa.gov/missions/mariner9/
First spacecraft to orbit another planet. Reached Mars in 1972 and transformed understanding of the Red Planet. Mariner 9's cameras discovered Olympus Mons and Valles Marineris.
Jupiter:
Jupiter Icy Moons Orbiter - prometheus.jpl.nasa.gov/
A NASA mission concept under study to explore possible subsurface oceans on Europa. As of 01/05, this mission is part of the “Prometheus” program, designed to develop nuclear-electric propulsion for deep space missions.
Galileo - www.jpl.nasa.gov/galileo/
First Jupiter orbiter, reached Jupiter in December 1995. Has conducted a seven year study of Jupiter's moons, radiation belts and atmosphere. During 1999-2001, Galileo has specifically targeted Io and Europa, making repeated mapping passes as it passes close to these moons.
Voyager 1 & 2 - vraptor.jpl.nasa.gov/voyager/voyager.html
Fly-by missions in 1979 & 1980, which discovered Jupiter's ring, volcanoes on Io, hinted at water on Europa, and provided striking images of atmospheric motions on Jupiter.
Pioneer - spaceprojects.arc.nasa.gov/Space Projects/pioneer/PNhome.html
Pioneer 10 and 11 were the first spacecraft to leave the inner solar system and reach Jupiter and Saturn, in 1974 and 1979 respectively.
Saturn:
Cassini - www.jpl.nasa.gov/cassini/
Launched in October 1997, Cassini was inserted into orbit around Jupiter in July 2004. First spacecraft to orbit Saturn, its 4-year mission is to study Saturn's rings, moons, and atmosphere.
Huygens Probe - www.jpl.nasa.gov/cassini/Spacecraft/probe.html and sci.esa.int/huygens/ The Huygens probe separated from Cassini and descended to the surface of Titan on 15-Jan-05, passing through Titan's surprisingly dense atmosphere. First landing on a moon in the solar system other than Earth’s moon.
Voyager 1 & 2 - http://vraptor.jpl.nasa.gov/voyager/voyager.html
Fly-by missions in 1980 & 1981 which discovered braided rings, shepherd satellites, ring “spokes", and Titan's atmosphere.
Uranus:
Voyager 2 - http://vraptor.jpl.nasa.gov/voyager/voyager.html
Fly-by mission in January 1986.
Neptune:
Voyager 2 - http://vraptor.jpl.nasa.gov/voyager/voyager.html
Fly-by mission in August 1989. Discovered ice geysers on Triton.
Pluto:
New Horizons - http://pluto.jhuapl.edu/
New Horizons is scheduled to launch in January 2006, swing past Jupiter for a gravity boost, and reach Pluto and its moon Charon, in July 2015. Then the spacecraft would head deeper into the Kuiper Belt to study one or more of the icy mini-worlds at the edge of the solar system. This mission is designed to reach and image Pluto before its current atmosphere re-freezes
Asteroids:
Dawn - http://www-ssc.igpp.ucla.edu/dawn/
Selected in December 2001, Dawn is NASA's 9th Discovery-class mission. Dawn will explore two of the largest protoplanets remaining intact since their formation: the asteroids Ceres and Vesta. Launch is planned in 2006, with arrival at Vesta in 2010, and Ceres in 2014.
Hayabusa -
NEAR - near.jhuapl.edu/
Launched in Feb 1996 as the first Discovery program mission, NEAR is the first spacecraft to orbit an asteroid. In February 2000, NEAR successfully rendezvoused with the asteroid 433 Eros, beginning a yearlong mission to determine its mass, structure, geology, composition, gravity, and magnetic fields. Eros is one of the largest near-Earth asteroids whose orbits cross that of Earth's. NEAR “soft"-landed on Eros in 2001.
Deep Space 1 - http://nmp.jpl.nasa.gov/ds1/
Flew by and imaged asteroid Braille in July 1999
Galileo - www.jpl.nasa.gov/galileo/
Enroute to Jupiter in the early 1990s, the Galileo spacecraft passed by and provided the first close-up images of asteroids.
Comets:
Rosetta – sci.esa.int/rosetta/
A mission of the European Space Agency with NASA participation, Rosetta is slated for launch in 2004. After a long cruise phase, it will rendezvous and orbit the comet 67P/Churyumov-Gerasimenko, orbiting around it making observations as it journeys towards the Sun. En route to the comet it will flyby at least one asteroid. A science package will be landed on the comet surface to make in-situ measurements. Rosetta will be the first attempt to actually land on a comet.
Deep Impact – deepimpact.umd.edu
The 8th Discovery program mission, selected in July 1999. Deep Impact will send a 500 kilogram copper cylinder into comet Tempel 1. This will be the first experiment to probe deep beneath the surface of a comet and will permit a variety of instruments, both onboard the spacecraft and observatories on Earth, to study the resulting debris and pristine interior material. Launch is set for January 2004 with impact" on July 4, 2005.
Stardust - stardust.jpl.nasa.gov/
Fourth Discovery program mission, launched in February 1999. First US mission to a comet, and the first attempted sample return from beyond the Moon. Comet dust and interstellar dust particles were collected during an encounter with the Comet Wild 2 in January 2004 and will be returned to Earth in 2006 for analysis.
CONTOUR - www.contour2002.org/index2.html
The Comet Nucleus Tour, or CONTOUR, mission was designed to encounter and study at least three comets as they make their periodic visits to the inner solar system. The 6th Discovery program mission CONTOUR was launched in July 2002 launch, and apparently exploded upon leaving Earth orbit.
Deep Space 1 - http://nmp.jpl.nasa.gov/ds1/
Flew by and imaged comet Borrelly in December 2001.