The Juno spacecraft, atop an Atlas 551 launch vehicle, lifted off from Kennedy Space Center on August 5, 2011. The spacecraft uses an energy efficient Delta V-EGA trajectory in transit to Jupiter ('delta V, Earth gravity assist'). This trajectory used deep space maneuvers on 30 August 2012 and 14 September 2012 followed by an Earth gravity assist (close flyby) on 9 October 2013, during which it passed by the Earth at an altitude of approximately 500 km.
Jupiter arrival (orbit insertion) occurs on 5 July 2016. The capture orbit and orbit to follow will be 53.5-day orbits prior to commencing operations. Juno's year-long prime mission (one Earth year) consists of 32 or more high inclination, high eccentricity orbits of Jupiter.
The orbit is polar (90 degrees inclination) with a periapsis altitude of about 4500 km and a semimajor axis of 19.91 RJ; the corresponding orbital period is 10.9725 days (Earth days). An alternative science orbit period of 14-days is also under consideration at this time.
The primary science is acquired during approximately 6 hours centered on each periapsis. However, fields and particles data are acquired at lower rates for the remaining portion of each orbit. All orbits will include fields and particles measurements of the planet's auroral regions.
The Juno Magnetometer (MAG) Investigation is a principal science investigation on the Juno New Frontier Mission to Jupiter. MAG will conduct the first global magnetic mapping of Jupiter and contribute to studies of Jupiter's polar magnetosphere. The Juno MAG investigation is designed to acquire highly accurate measurements of the magnetic field in Jupiter's environment, mapping the planetary magnetic field with extraordinary accuracy and spatial resolution (orders of magnitude better than current knowledge).
The MAG Instrument Suite consists of two boom mounted observing platforms (MAG Optical Bench, or MOB) each supporting a vector Fluxgate Magnetometer (FGM) and two non-magnetic Advanced Stellar Compass (ASC) Camera Head Units (CHUs). The FGM uses two miniature ring-core fluxgate sensors to measure the magnetic field in three components of the vector field. The ASC determines the attitude of the MOB in inertial space and relative to the JUNO spacecraft's Stellar Reference Units (SRU). The FGM was built at the Goddard Space Flight Cen