The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 UTC, as part of the New Frontiers program.

[8] After completing its mission, Juno was originally planned to be intentionally deorbited into Jupiter's atmosphere,[8] but has since been approved to continue orbiting until contact is lost with the spacecraft.

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.

[25] During the science mission, infrared and microwave instruments will measure the thermal radiation emanating from deep within Jupiter's atmosphere.

[26] The probe was then intended to be deorbited and burnt up in Jupiter's outer atmosphere[4][5] to avoid any possibility of impact and biological contamination of one of its moons.

[27] Juno was launched atop an Atlas V (551 configuration) at Cape Canaveral Air Force Station (CCAFS), Florida on August 5, 2011, 16:25:00 UTC.

When heating levels had dropped below predetermined limits, the payload fairing that protected Juno during launch and transit through the thickest part of the atmosphere separated, about 3 minutes 24 seconds into the flight.

[38] On July 5, 2016, between 03:18 and 03:53 UTC Earth-received time, an insertion burn lasting 2,102 seconds decelerated Juno by 542 m/s (1,780 ft/s)[39] and changed its trajectory from a hyperbolic flyby to an elliptical, polar orbit with a period of about 53.5 days.

An eccentricity-reducing burn, called the Period Reduction Maneuver, was planned that would drop the probe into a much shorter 14 day science orbit.

[49] On October 14, 2016, days prior to perijove 2 and the planned Period Reduction Maneuver, telemetry showed that some of Juno's helium valves were not opening properly.

[61][56] The controlled deorbit is intended to eliminate space debris and risks of contamination in accordance with NASA's planetary protection guidelines.

[62][63][64] Scott Bolton of the Southwest Research Institute in San Antonio, Texas is the principal investigator and is responsible for all aspects of the mission.

The Jet Propulsion Laboratory in California manages the mission and the Lockheed Martin Corporation was responsible for the spacecraft development and construction.

[80](Principal investigator: Mike Janssen, Jet Propulsion Laboratory) The spectrometer mapper JIRAM, operating in the near infrared (between 2 and 5 μm), conducts surveys in the upper layers of the atmosphere to a depth of between 50 and 70 km (31 and 43 mi) where the pressure reaches 5 to 7 bar (500 to 700 kPa).

By measuring the heat radiated by the atmosphere of Jupiter, JIRAM can determine how clouds with water are flowing beneath the surface.

[80](Principal investigator: Alberto Adriani, Italian National Institute for Astrophysics) JIRAM's spin-compensation mirror is stuck since PJ44, but the instrument is operational.

[75](Principal investigator: Jack Connerney, NASA's Goddard Space Flight Center) The purpose of measuring gravity by radio waves is to establish a map of the distribution of mass inside Jupiter.

The uneven distribution of mass in Jupiter induces small variations in gravity all along the orbit followed by the probe when it runs closer to the surface of the planet.

[85][86][74](Principal investigator: John Anderson, Jet Propulsion Laboratory; Principal investigator (Juno's Ka-band Translator): Luciano Iess, Sapienza University of Rome) The energetic particle detector JADE will measure the angular distribution, energy, and the velocity vector of ions and electrons at low energy (ions between 13 eV and 20 KeV, electrons of 200 eV to 40 KeV) present in the aurora of Jupiter.

On JADE, like JEDI, the electron analyzers are installed on three sides of the upper plate which allows a measure of frequency three times higher.

[74][87](Principal investigator: David McComas, Southwest Research Institute) The energetic particle detector JEDI will measure the angular distribution and the velocity vector of ions and electrons at high energy (ions between 20 keV and 1 MeV, electrons from 40 to 500 keV) present in the polar magnetosphere of Jupiter.

[75](Principal investigator: G. Randall Gladstone, Southwest Research Institute) A visible light camera/telescope, included in the payload to facilitate education and public outreach; later re-purposed to study the dynamics of Jupiter's clouds, particularly those at the poles.

[104] The solar panels will remain in sunlight continuously from launch through the end of the mission, except for short periods during the operation of the main engine and eclipses by Jupiter.

Two 55 Ah lithium-ion batteries that are able to withstand the radiation environment of Jupiter provide power when Juno passes through eclipse.

[105] Juno uses in-band signaling ("tones") for several critical operations as well as status reporting during cruise mode,[106] but it is expected to be used infrequently.

[105] The command and data processing of the Juno spacecraft includes a flight computer capable of providing about 50 Mbit/s of instrument throughput.

This is comparable to the previous Galileo mission that orbited Jupiter, which captured thousands of images[109] despite its slow data rate of 1000 bit/s (at maximum compression level) due to the failure of its high gain antenna.

[113] The figurines were produced in partnership between NASA and Lego as part of an outreach program to inspire children's interest in science, technology, engineering, and mathematics (STEM).

[117] In 2021, analysis of the frequency of interplanetary dust impacts (primarily on the backs of the solar panels), as Juno passed between Earth and the asteroid belt, indicated that this dust, which causes the Zodiacal light, comes from Mars, rather than from comets or asteroids that come from the outer solar system, as was previously thought.

With Juno traveling low over Jupiter's cloud deck at about 130,000 mph (209,000 kph) Juno scientists were able to measure velocity changes as small 0.01 millimeter per second using a NASA's Deep Space Network tracking antenna, from a distance of more than 400 million miles (650 million kilometers).