Juno (spacecraft)
Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is 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. Juno entered a polar orbit of Jupiter on July 5, 2016, UTC, to begin a scientific investigation of the planet. After completing its mission, Juno will be intentionally deorbited into Jupiter's atmosphere.
Artist's rendering of the Juno spacecraft | |||||||||||||||||||
| Names | New Frontiers 2 | ||||||||||||||||||
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| Mission type | Jupiter orbiter | ||||||||||||||||||
| Operator | NASA / Jet Propulsion Laboratory | ||||||||||||||||||
| COSPAR ID | 2011-040A | ||||||||||||||||||
| SATCAT no. | 37773 | ||||||||||||||||||
| Website | |||||||||||||||||||
| Mission duration | Planned: 7 years Elapsed: 12 years, 8 months, 11 days Cruise: 4 years, 10 months, 29 days Science phase: 2 years, 8 months and 18 days (in progress) (extended until September 2025) | ||||||||||||||||||
| Spacecraft properties | |||||||||||||||||||
| Manufacturer | Lockheed Martin Space | ||||||||||||||||||
| Launch mass | 3,625 kg (7,992 lb) | ||||||||||||||||||
| Dry mass | 1,593 kg (3,512 lb) | ||||||||||||||||||
| Dimensions | 20.1 × 4.6 m (66 × 15 ft) | ||||||||||||||||||
| Power | 14 kW at Earth, 435 W at Jupiter 2 × 55-ampere hour lithium-ion batteries | ||||||||||||||||||
| 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, 7 years, 9 months, 12 days ago | ||||||||||||||||||
| Orbits | 76 (planned) | ||||||||||||||||||
| 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 program | |||||||||||||||||||
Juno's mission is to measure Jupiter's composition, gravitational field, magnetic field, and polar magnetosphere. It will also search 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).
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 planets, Juno is powered by solar panels, commonly used by satellites orbiting Earth and working in the inner Solar System, whereas radioisotope thermoelectric generators are commonly used for missions to the outer Solar System and beyond. For Juno, however, the three largest solar panel wings ever deployed on a planetary probe (at the time of launching) play an integral role in stabilizing the spacecraft as well as generating power.