The Juno spacecraft successfully completed its fourth flyby of Jupiter in the first week of February 2017. During the flyby, all the eight scientific instruments on board the spacecraft were switched on. Compared to its previous three flyby operations, the fourth flyby was closest to the Jupiter.
During the present operation, the spacecraft was located at 4,300 km above Jupiter’s cloud tops and was travelling at a speed of about 2,08,000 kilometers per hour (kmph).
• It was designed and developed by the National Aeronautics and Space Administration (NASA) of the USA.
• The Juno spacecraft was launched on 5 August 2011 aboard an Atlas V-551 rocket from Cape Canaveral, Florida in the USA.
• Juno is the first solar-powered spacecraft designed by NASA to operate at such a great distance from the sun.
• In order to avoid most of Jupiter's high radiation regions, it uses a spinning solar-powered spacecraft in a highly elliptical polar orbit.
• The designs of the individual instruments are straightforward and the mission does not require the development of any new technologies.
• Juno's scientific payloads are -
i. A gravity/radio science system (Gravity Science)
ii. A six-wavelength microwave radiometer for atmospheric sounding and composition (MWR)
iii. A vector magnetometer (MAG)
iv. Plasma and energetic particle detectors (JADE and JEDI)
v. A radio/plasma wave experiment (Waves)
vi. An ultraviolet imager/spectrometer (UVS)
vii. An infrared imager/spectrometer (JIRAM)
• The spacecraft also carries a color camera, which is called as JunoCam. The camera provides the first detailed glimpse of Jupiter's poles to the public.
• Juno carries a radiation shielded electronics vault, a critical feature for enabling sustained exploration in such a heavy radiation environment.
• This feature of the mission is relevant to NASA's Vision for Space Exploration, which addresses the need for protection against harsh radiation in space environments beyond the safety of low-Earth orbit.