Juno (spacecraft)
Artist's rendering of the Juno spacecraft | |||||||||||||||||||
| Names | New Frontiers 2 | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mission type | Jupiter orbiter | ||||||||||||||||||
| Operator | NASA / Jet Propulsion Laboratory | ||||||||||||||||||
| COSPAR ID | 2011-040A | ||||||||||||||||||
| SATCAT no. | 37773 | ||||||||||||||||||
| Website | |||||||||||||||||||
| Mission duration | Planned: 7 years Elapsed: 14 years, 1 month, 13 days Cruise: 4 years, 10 months, 29 days Science phase: 4 years, 1 month and 20 days (in progress; extended until September 2025) | ||||||||||||||||||
| Spacecraft properties | |||||||||||||||||||
| Manufacturer | Lockheed Martin Space | ||||||||||||||||||
| Launch mass | 3,625 kg (7,992 lb)[1] | ||||||||||||||||||
| Dry mass | 1,593 kg (3,512 lb)[2] | ||||||||||||||||||
| Dimensions | 20.1 × 4.6 m (66 × 15 ft)[2] | ||||||||||||||||||
| Power | 14 kW at Earth,[2] 435 W at Jupiter [1] 2 × 60-ampere hour, 28 Volt lithium-ion batteries[3] | ||||||||||||||||||
| Start of mission | |||||||||||||||||||
| Launch date | August 5, 2011, 16:25:00 UTC | ||||||||||||||||||
| Rocket | Atlas V 551 (AV-029) | ||||||||||||||||||
| Launch site | Cape Canaveral, SLC-41 | ||||||||||||||||||
| Contractor | United Launch Alliance | ||||||||||||||||||
| Flyby of Earth | |||||||||||||||||||
| Closest approach | October 9, 2013 | ||||||||||||||||||
| Distance | 559 km (347 mi) | ||||||||||||||||||
| Jupiter orbiter | |||||||||||||||||||
| Orbital insertion | July 5, 2016,[4] 9 years, 2 months, 14 days ago | ||||||||||||||||||
| Orbits | 76 (planned)[5][6] | ||||||||||||||||||
| Orbital parameters | |||||||||||||||||||
| Perijove altitude | 4,200 km (2,600 mi) altitude 75,600 km (47,000 mi) radius | ||||||||||||||||||
| Apojove altitude | 8.1×106 km (5.0×106 mi) | ||||||||||||||||||
| Inclination | 90° (polar orbit) | ||||||||||||||||||
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Juno mission patch New Frontiers | |||||||||||||||||||
Juno is a NASA space probe orbiting the planet Jupiter. Built by Lockheed Martin and operated by NASA's Jet Propulsion Laboratory, the spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 UTC, as part of the New Frontiers program.[7] Juno entered a polar orbit of Jupiter on July 5, 2016, UTC,[5][8] to begin a scientific investigation of the planet.[9] After completing its mission, Juno was originally planned to be intentionally deorbited into Jupiter's atmosphere,[9] but has since been approved to continue orbiting until contact is lost with the spacecraft,[10] but it is scheduled to be shut down per the FY2026 budget proposed by the second Donald Trump administration.[11] However, if Juno mission receives a third mission extension, it will continue to explore Jupiter for another three years to study Jovian rings and inner moons area which is not well explored;[12] this phase will also include close flybys of the moons Thebe, Amalthea, Adrastea, and Metis.[13]
Juno's mission is to measure Jupiter's composition, gravitational field, magnetic field, and polar magnetosphere. It also searches for clues about how the planet formed, including whether it has a rocky core, the amount of water present within the deep atmosphere, mass distribution, and its deep winds, which can reach speeds up to 620 km/h (390 mph).[14]
Juno is the second spacecraft to orbit Jupiter, after the nuclear powered Galileo orbiter, which orbited from 1995 to 2003. Unlike all earlier spacecraft sent to the outer Solar System and beyond—which used radioisotope thermoelectric generators for power—Juno is powered by solar panels, more commonly used by satellites orbiting Earth and working in the inner Solar System.[9] Accordingly, Juno required the three largest solar panel wings ever deployed on a planetary probe (at the time of launching). These play an integral role in stabilizing the spacecraft as well as generating power.[15]
- ^ a b "Juno Mission to Jupiter" (PDF). NASA FACTS. NASA. April 2009. p. 1. Archived (PDF) from the original on April 6, 2020. Retrieved April 5, 2011. This article incorporates text from this source, which is in the public domain.
- ^ a b c "Jupiter Orbit Insertion Press Kit" (PDF). NASA. 2016. Archived (PDF) from the original on August 14, 2016. Retrieved July 7, 2016. This article incorporates text from this source, which is in the public domain.
- ^ "Batteries Space Exploration EaglePicher". www.eaglepicher.com. Retrieved September 17, 2025.
- ^ Foust, Jeff (July 5, 2016). "Juno enters orbit around Jupiter". SpaceNews. Archived from the original on December 31, 2016. Retrieved August 25, 2016.
- ^ a b Chang, Kenneth (July 5, 2016). "NASA's Juno Spacecraft Enters Jupiter's Orbit". The New York Times. Archived from the original on May 2, 2019. Retrieved July 5, 2016.
- ^ Greicius, Tony (September 21, 2015). "Juno – Mission Overview". NASA. Archived from the original on September 7, 2018. Retrieved October 2, 2015. This article incorporates text from this source, which is in the public domain.
- ^ Dunn, Marcia (August 5, 2011). "NASA probe blasts off for Jupiter after launch-pad snags". NBC News. Archived from the original on September 14, 2019. Retrieved August 31, 2011.
- ^ Chang, Kenneth (June 28, 2016). "NASA's Juno Spacecraft Will Soon Be in Jupiter's Grip". The New York Times. Archived from the original on August 14, 2018. Retrieved June 30, 2016.
- ^ a b c Riskin, Dan (July 4, 2016). Mission Jupiter (Television documentary). Science Channel.
- ^ Mission to Jupiter: Juno, JPL: "Now in its extended mission, Juno will continue its investigation of the solar system’s largest planet through September 2025, or until the spacecraft’s end of life."
- ^ "New NASA budget would shut down 41 space missions".
- ^ Bruce Dorminey (May 7, 2025). Scott Bolton, NASA Juno mission principal investigator. Retrieved August 18, 2025 – via YouTube.
- ^ "Scientists behind threatened NASA missions explain what's at stake". The Planetary Society. Retrieved August 18, 2025.
- ^ Cheng, Andrew; Buckley, Mike; Steigerwald, Bill (May 21, 2008). "Winds in Jupiter's Little Red Spot Almost Twice as Fast as Strongest Hurricane". NASA. Archived from the original on May 13, 2017. Retrieved August 9, 2017. This article incorporates text from this source, which is in the public domain.
- ^ "Juno's Solar Cells Ready to Light Up Jupiter Mission". NASA. July 15, 2011. Archived from the original on April 26, 2020. Retrieved April 26, 2020. This article incorporates text from this source, which is in the public domain.