Juno at Jupiter

On Dec. 21, at 8:49:48 a.m. PST NASA’s Juno spacecraft was 3,140 miles (5,053 kilometers) above Jupiter’s cloud tops and hurtling by at a healthy clip of 128,802 mph (207,287 kilometers per hour). This was the 16th science pass of the gas giant marking the solar-powered spacecraft’s halfway point in data collection during its prime mission. Juno was in a highly-elliptical 53-day orbit around Jupiter. Each orbit included a close passage over the planet’s cloud deck, where it flew a ground track that extended from Jupiter’s north pole to its south pole. Launched on Aug. 5, 2011, from Cape Canaveral, Florida, the spacecraft entered orbit around Jupiter on July 4, 2016. Its science collection began in earnest on the Aug. 27, 2016, flyby. During these flybys, Juno’s suite of sensitive science instruments probes beneath the planet’s obscuring cloud cover and studies Jupiter’s auroras to learn more about the planet’s origins, interior structure, atmosphere and magnetosphere. Two instruments aboard Juno, the Stellar Reference Unit and JunoCam, have proven to be useful not only for their intended purposes, but also for science data collection. The Stellar Reference Unit (SRU) was designed to collect engineering data used for navigation and attitude determination, so the scientists were pleased to find that it has scientific uses as well. The JunoCam imager was conceived as an outreach instrument to bring the excitement and beauty of Jupiter exploration to the public. The SRU and JunoCam teams both now have several peer-reviewed science papers -either published or in the works – to their credit. NASA’s JPL manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for NASA’s Science Mission Directorate. The Italian Space Agency (ASI) contributed two instruments, a Ka-band frequency translator (KaT) and the Jovian Infrared Auroral Mapper (JIRAM). Lockheed Martin Space in Denver built the spacecraft.