A total of nine spacecraft have been launched on missions that involve visits to the outer planets; all nine missions involve encounters with Jupiter, with four spacecraft also visiting Saturn. One spacecraft, Voyager 2 , also visited Uranus and Neptune. The nine missions include two, Ulysses and New Horizons , whose primary objectives were not outer planets, but which flew past Jupiter to gain gravity assists en route to a polar orbit around the Sun (Ulysses), and to Pluto (New Horizons). Pluto was considered a planet at the time that New Horizons launched, but was reclassified as a dwarf planet. Cassini–Huygens also flew past Jupiter for a gravity assist on its mission to explore Saturn.
Only three of the missions to the outer planets have been orbiters: Galileo orbited Jupiter for eight years, while Cassini orbited Saturn for thirteen years. Juno has been orbiting Jupiter since 2016.
System Spacecraft | Jupiter Jupiter trojans | Saturn | Uranus Uranus trojans | Neptune Neptune trojans | Pluto Trans-Neptunian objects |
---|---|---|---|---|---|
Pioneer 10 | 1973 flyby Jupiter and moons | ||||
Pioneer 11 | 1974 flyby Jupiter and moons | 1979 flyby Saturn and moons | |||
Voyager 1 | 1979 flyby Jupiter and moons | 1980 flyby Saturn and moons | |||
Voyager 2 | 1979 flyby Jupiter and moons | 1981 flyby Saturn and moons | 1986 flyby Uranus and moons | 1989 flyby Neptune and moons | |
Ulysses | 1992, 2004 gravity assist Jupiter | ||||
Galileo | 1995–2003 orbiter Jupiter and moons 1995 atmospheric Jupiter | ||||
Cassini–Huygens | 2000 gravity assist Jupiter and moons | 2004–2017 orbiter Saturn and moons 2005 lander Titan | |||
New Horizons | 2007 gravity assist Jupiter and moons | 2015 flyby Pluto and moons 2019 flyby 486958 Arrokoth | |||
Juno | 2016–2025 orbiter Jupiter | ||||
Lucy | 2027– flyby mission (launched 2021) 3548 Eurybates 15094 Polymele 11351 Leucus 21900 Orus 617 Patroclus | ||||
Jupiter Icy Moons Explorer | 2031– orbiter mission (launched 2023) Jupiter and Ganymede | ||||
Europa Clipper | 2030– orbiter mission (launched 2024) Europa |
Nine spacecraft have been launched to explore Jupiter, with two other spacecraft making gravity-assist flybys.
New Horizons, although eventually targeting Pluto, used Jupiter for a gravity assist and had an extensive almost half year observation campaign of Jupiter and its moons (hence it is counted in the eight). [1]
Mission | Spacecraft | Launch date | Carrier rocket | Operator | Mission Type | Outcome | |
---|---|---|---|---|---|---|---|
1 | Pioneer 10 | Pioneer 10 | 3 March 1972 [2] | Atlas SLV-3C Centaur-D [3] | ![]() | Flyby | Successful [4] |
Humanity's first object to attain Solar system's escape velocity. First probe to traverse the asteroid belt, to reach Jovanian system, to use a gravity assist and to leave the proximity of Solar systems' planets. Held the record for fastest human-made object at the time and the most distant one until Voyager 1 overtook in 1998. Closest approach towards Jupiter was at 02:25 UTC on 4 December 1973. Flew by Callisto, Ganymede, Europa and Io at long distances. Final signal received on 23 January 2003, 12 billion km (80 AU; 7.5 billion mi) from Earth. [5] | |||||||
2 | Pioneer 11 | Pioneer 11 | 6 April 1973 [2] | Atlas SLV-3D Centaur-D1A [3] | ![]() | Flyby | Successful [6] |
Closest approach towards Jupiter at 05:22 UTC on 3 December 1974. Flew by Callisto, Ganymede, Io and Europa . First probe to reach Saturnian system. Final contact was roughly at a distance of 6.5 billion km (43 AU; 4.0 billion mi) [7] | |||||||
3 | Voyager 2 | Voyager 2 | 20 August 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Closest approach at 22:29 on 9 July 1979. Flew past Callisto, Ganymede, Europa, Amalthea and Io at long distances. Later flew past Saturn, Uranus and Neptune. Oldest active space probe at 47 years, 5 months, 22 days. Currently studying interstellar medium. At a distance of 136.1 AU (20.4 billion km ; 12.7 billion mi ) from Earth as of May 2024 [update] [9] | |||||||
4 | Voyager 1 | Voyager 1 | 5 September 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Closest approach at 12:05 UTC on 5 March 1979. Flew past Amalthea, Europa, Ganymede and Callisto at long distances. Later flew past Saturn. First probe to depart heliosphere and enter interstellar medium. Most distant human-made object at a distance of 162.7 AU (24.3 billion km ; 15.1 billion mi ) from Earth as of May 2024 [update] . [10] | |||||||
5 | Galileo project | Galileo | 18 October 1989 [2] | Space Shuttle Atlantis STS-34 / IUS [11] | ![]() | Orbiter | Successful [12] |
Atmopsheric entry probe | Atmospheric probe | Successful [12] | |||||
First probe to enter Jupiter's atmosphere. Entered at 22:04 UTC on 7 December 1995 and operated for 57 minutes; main spacecraft entered orbit at 00:27 UTC on 8 December. [13] Spacecraft was deorbited on 21 September 2003, impacting Jupiter's atmosphere at 18:57:18 UTC. [14] | |||||||
– | Ulysses | Ulysses | 6 October 1990 [2] | Space Shuttle Discovery STS-41 / IUS [15] | ![]() ![]() | Flyby | Successful |
Flyby on 8 February 1992 to reach a high-inclination heliocentric orbit. [16] Also made a distant incidental flyby on 4 February 2004 [17] | |||||||
– | Cassini–Huygens | Cassini | 15 October 1997 [2] | Titan IV(401)B Centaur-T [18] | ![]() ![]() | Flyby | Successful |
Huygens lander | Successful | ||||||
Flyby on 30 December 2000 en route to Saturn [19] | |||||||
6 | New Horizons | New Horizons | 19 January 2006 [2] | Atlas V 551 [20] | ![]() | Flyby | Successful |
Gravity assist. [20] Major observation campaign from Jan-June. [1] Flyby on 28 February 2007 (closest approach at 05:43:40 [21] ) en route to Pluto. [22] First probe to flyby Plutonian system. | |||||||
7 | Juno | Juno | 5 August 2011 [2] | Atlas V 551 [23] | ![]() | Orbiter | Operational |
Entered orbit 4 July 2016. First outer planet explorer probe with solar panels. [24] | |||||||
8 | Juice | JUICE | 14 April 2023 | Ariane 5 ECA | ![]() | Orbiter | En route |
First interplanetary probe to the outer Solar System planets not launched by the United States and the first set to orbit a moon (Ganymede) other than Earth's Moon. | |||||||
9 | Europa Clipper | Europa Clipper | 14 October 2024 | Falcon Heavy | ![]() | Orbiter | En route |
Jupiter orbiter with Europa flybys |
Four spacecraft have visited Saturn; Pioneer 11, Voyager 1 and Voyager 2 made flybys, while Cassini–Huygens entered orbit, and deployed a probe into the atmosphere of Titan.
Mission | Spacecraft | Launch date | Carrier rocket | Operator | Mission Type | Outcome | |
---|---|---|---|---|---|---|---|
1 | Pioneer 11 | Pioneer 11 | 6 April 1973 | Atlas SLV-3D Centaur-D1A [3] | ![]() | Flyby | Successful |
First probe to reach Saturnian system. Closest approach on 1 September 1979 at 16:31 UTC. Flew past Iapetus, Dione, Mimas, Tethys, Enceladus, Rhea and Titan at long distances. Discovered Epimetheus and Janus. [7] | |||||||
2 | Voyager 2 | Voyager 2 | 20 August 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Closest approach at 01:21 UTC on 26 August 1981. Flew past Iapetus, Titan, Dione, Mimas, Enceladus, Tethys and Rhea at long distances. Later flew past Uranus and Neptune. [9] | |||||||
3 | Voyager 1 | Voyager 1 | 5 September 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Closest approach on 12 November 1980 at 23:45 UTC. Flew past Titan, Tethys, Mimas, Enceladus and Rhea. [10] [9] | |||||||
4 | Cassini–Huygens | Cassini | 15 October 1997 [2] | Titan IV(401)B Centaur-T [18] | ![]() | Orbiter | Successful |
Huygens | ![]() | Titan lander | Successful | ||||
Entered orbit 1 July 2004. First probe to orbit Saturn. Discovered seven new moons. Hyugens probe became the first spacecraft to land on Titan with the farthest landing from Earth a spacecraft ever made. It was deployed from Cassini and landed at 10:13 UTC on 14 January 2005. Mission concluded on 15 September 2017. [25] |
Voyager 2 is the only spacecraft to have visited Uranus, making a single flyby as part of its grand tour of the outer planets.
Mission | Spacecraft | Launch date | Carrier rocket | Operator | Mission Type | Outcome | |
---|---|---|---|---|---|---|---|
1 | Voyager 2 | Voyager 2 | 20 August 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Discovered eleven moons. Flew past Miranda, Ariel, Umbriel, Titania and Oberon. Closest approach at 17:59 UTC on 24 January 1986. Later flew past Neptune. [9] |
Voyager 2 is the only spacecraft to have visited Neptune, making a single flyby as part of its grand tour of the outer planets.
Mission | Spacecraft | Launch date | Carrier rocket | Operator | Mission Type | Outcome | |
---|---|---|---|---|---|---|---|
1 | Voyager 2 | Voyager 2 | 20 August 1977 [2] | Titan IIIE Centaur-D1T [8] | ![]() | Flyby | Successful |
Discovered Neptunian rings and six new moons. Flew past Galatea, Larissa, Proteus and Triton. Closest approach at 03:26 UTC on 25 August 1989 [9] |
New Horizons is the only spacecraft that visited dwarf planet Pluto (in 2015) and the trans-Neptunian object 486958 Arrokoth (in 2019).
Mission | Spacecraft | Launch date | Carrier rocket | Operator | Mission Type | Outcome | |
---|---|---|---|---|---|---|---|
1 | New Horizons | New Horizons | 19 January 2006 | Atlas V (551) AV-010 + Star 48B 3rd stage | ![]() | Flyby | Successful |
Flew by Pluto in July 2015, flew past Arrokoth on 1 January 2019. |
Milestone achieved
Milestone not achieved
En route
† First to achieve
Country/Agency | Jupiter | Saturn | Uranus | Neptune | ||||
---|---|---|---|---|---|---|---|---|
Flyby | Orbit | Artmospheric entry | Flyby | Orbit | Artmospheric entry | Flyby | Flyby | |
![]() | Pioneer 10, 1973 † | Galileo, 1995 † | Atmospheric probe, 1995 † | Pioneer 11, 1979 † | Cassini, 2004 † | Cassini, 2017 † | Voyager 2, 1986 † | Voyager 2, 1989 † |
![]() | Ulysses, 1992 | — | — | — | — | — | — | — |
Country/Agency | Ganymede | Callisto | Io | Europa | |
---|---|---|---|---|---|
Flyby | Orbit | Flyby | Flyby | Flyby | |
![]() | Pioneer 10, 1973 † | — | Pioneer 10, 1973 † | Pioneer 10, 1973 † | Pioneer 10, 1973 † |
![]() | Juice, TBD 2034 | Juice, TBD 2034 | — | — | — |
Country/Agency | Titan | Rhea | Iapetus | Dione | Tethys | Enceladus | Mimas | ||
---|---|---|---|---|---|---|---|---|---|
Flyby | Orbit | Lander | Flyby | Flyby | Flyby | Flyby | Flyby | Flyby | |
![]() | Pioneer 11, 1979 † | — | — | Pioneer 11, 1979 † | Pioneer 11, 1979 † | Pioneer 11, 1979 † | Pioneer 11, 1979 † | Pioneer 11, 1979 † | Pioneer 11, 1979 † |
![]() | — | — | Huygens, 2005 † | — | — | — | — | — | — |
Mission | Spacecraft | Launch date | Carrier rocket | Operator |
---|---|---|---|---|
Planned missions | ||||
Dragonfly | Dragonfly | TBD July 2028 | TBD | ![]() |
Titan robotic rotorcraft | ||||
Tianwen-4 | Tianwen-4 | TBD September 2029 | TBD | ![]() |
Uranus flyby probe | ||||
Jupiter and Callisto orbiter; Flyby past Uranus with mission extension planned for interstellar journey | ||||
Proposed missions | ||||
IHP-1 | Shensuo | TBD | TBD | ![]() |
Interstellar heliospheric probe with Jovian gravity assist; planned flybys of Jupiter and 50000 Quaoar | ||||
IHP-2 | Shensuo | TBD | TBD | ![]() |
Interstellar heliospheric probe with Jovian gravity assist; planned flybys of Jupiter, Neptune, Triton and a Kuiper belt object | ||||
Uranus Orbiter and Probe | Uranus orbiter | NET 2031 | Falcon Heavy (expendable) | ![]() |
Uranus probe | ||||
Uranus orbiter after a flyby of Jupiter; Uranus atmospheric probe | ||||
Enceladus Orbilander | Enceladus Orbilander | NET 2038 | ![]() | |
Enceladus orbiter/lander |