The Juno Magnetic Field Investigation (MAG): Exploration of the Polar Magnetosphere

The Juno MAG investigation is part of a fields and particles instrumentation package that will explore Jupiter's polar magnetosphere and aurorae. The Juno mission design provides 32 high inclination orbits equally spaced in longitude; the Juno spacecraft will repeatedly pass through Jupiter's auroral curtains over both poles. The MAG investigation is implemented with a pair of highly accurate vector fluxgate magnetometers mounted on a dedicated magnetometer boom at 10 and 12 m from the spacecraft body. The MAG boom is itself a 4 m rigid appendage supported at the outer extremity of one of three solar array assemblies that radiate from the body of the spacecraft. Each vector fluxgate sensor is mounted on an optical bench in close proximity with two precision non-magnetic star cameras provided by the Danish Technical University (John Lief Jorgensen) which allow accurate attitude determination at each of the MAG sensors. Both MAG sensors are sampled at a native rate of 64 vector samples/s throughout periapsis, and averaged and decimated elsewhere throughout the orbit to reduce demand on s/c telemetry. The MAG investigation will map out the distribution of field aligned currents in the polar regions, and contribute to understanding of Jovian aurorae, magnetosphere-ionosphere coupling, and angular momentum transfer in the Jovian system.