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 whichit 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) consistsof 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 scienceorbit 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 auroralregions.

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 magnitudebetter 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 Center (GSFC); the ASC wasbuilt at the Technical University of Denmark (DTU).

The Juno MAG sensors are remotely mounted (at approximately 10 m and 12 m) along a dedicated MAG boom that extends along the spacecraft +x axis, attached to the outer end of one of the spacecraft's three solar arraystructures.

The JUNO sensor design covers the wide dynamic range with six instrument ranges (see below) increasing by factors of four the dynamic range in successive steps. The analog signals are digitized with a 16 bit analog to digital (A/D) converter, which yields a resolution of +/- 32768 steps for each dynamic range. In the table below, resolution, equal to halfthe quantization step size for each range, is listed in parentheses.

FGM Characteristics Dual Tri-Axial Ring Core Fluxgate
Dynamic range (resolution) 16.3840 G (+/-25.0 nT) 4.0960 G (+/-6.25 nT) 1.0240 G (+/-1.56 nT) 0.2560 G (+/-0.391 nT) (1 G = 100,000 nT) 6400 nT (+/-0.10 nT) 1600 nT (+/-0.02 nT) Measurement accuracy: 0.01% absolute vector accuracy Intrinsic noise level <<1 nT (range dependent) Zero level stability <1 nT (calibrated) Intrinsic sample rate 64 vector samples/s
The data from each sensor can be in one of eight data formats. The instrument intrinsic sample rate of 64 samples/second is supported in data formats 0 and 1; averages over 2 to the n power samples(n = 1,2,3,4,5,6) are supported in telemetry modes 2 through 7.

The MAG instrument suite is described in full detail in[CONNERNEYAL2016].