Juno spacecraft

Juno spacecraft is a NASA mission designed to study the gas giant Jupiter. Launched in 2011, it entered a polar orbit around the planet in 2016 to conduct an in-depth investigation of its atmosphere, interior structure, magnetic field, and magnetosphere. The mission aims to understand Jupiter's origin and evolution, which holds key insights into the formation of our own Solar System.

Mission overview

The primary scientific objectives focus on determining the abundance of water, mapping Jupiter's intense magnetic and gravitational fields, and exploring the turbulent atmosphere. Managed by NASA's Jet Propulsion Laboratory, the mission seeks to answer fundamental questions about the planet's core and the dynamics of its famous Great Red Spot. By studying this archetype for giant planets, data contributes to planetary science across the cosmos, informing theories about exoplanets discovered by missions like Kepler space telescope.

Spacecraft design

The robotic probe features a unique design optimized for the harsh radiation environment of Jupiter. Built by Lockheed Martin, its most distinctive feature is a trio of very large solar panels, a first for an outer-planet mission, which provide power. The spacecraft body is protected by a titanium radiation vault to shield its sensitive electronics. Its spin-stabilized design provides pointing stability for instruments like the JunoCam and the Advanced Stellar Compass.

Scientific instruments

A suite of nine instruments carries out the investigation. The Microwave Radiometer probes deep atmospheric composition, while the Magnetometer maps the planetary magnetic field in detail. The Jovian Infrared Auroral Mapper studies auroral phenomena, and the Ultraviolet Spectrograph analyzes the upper atmosphere. Other key tools include the Jovian Auroral Distributions Experiment, the Radio and Plasma Wave Sensor, and the Gravity Science experiment which uses the Deep Space Network for measurements.

Mission timeline and trajectory

Launched aboard an Atlas V rocket from Cape Canaveral Space Force Station in 2011, the spacecraft utilized a gravity assist from Earth in 2013 to reach Jupiter. It successfully performed a critical Jupiter orbit insertion burn in July 2016. The original plan involved 32 science orbits, but the mission has been extended multiple times by NASA. Its elongated orbit, designed to minimize radiation exposure, takes it from close perijove passes out to great distances from the planet.

Key discoveries and results

Findings have revolutionized understanding of Jupiter. Data revealed that the planet's iconic bands extend thousands of kilometers deep and that its core is diffuse or partially dissolved. The Magnetometer showed Jupiter's magnetic field is far more irregular than models predicted. Observations of the polar regions revealed chaotic clusters of cyclones and provided stunning imagery of the poles for the first time. Measurements from the Microwave Radiometer indicated an unexpectedly asymmetric distribution of ammonia.

Future plans and mission extension

Having completed its primary mission, the spacecraft continues to operate under an extended mission phase. Current plans involve continued close study of Jupiter's atmosphere, rings, and magnetosphere, as well as targeted flybys of its large moons, including Ganymede, Europa, and Io. These encounters, such as the close pass of Europa in 2022, provide valuable data for future missions like the Europa Clipper. The mission is expected to continue collecting data until at least 2025.