Radiation Belt Storm Probes—Observatory and Environments

Abstract

The National Aeronautics and Space Administration's (NASA's) Radiation Belt Storm Probe (RBSP) is an Earth-orbiting mission that launched August 30, 2012, and is the latest science mission in NASA's Living with a Star Program. The RBSP mission will investigate, characterize and understand the physical dynamics of the radiation belts, as well as the influence of the Sun on the Earth's environment, by measuring particles, electric and magnetic fields and waves that comprise geospace. The mission is composed of two identically instrumented spinning observatories in an elliptical orbit around earth with 600 km perigee, 30,000 km apogee and 10• inclination to provide full sampling of the Van Allen radiation belts. The twin RBSP observatories (recently renamed the Van Allen Probes) will follow slightly different orbits and will lap each other four times per year, offering simultaneous measurements over a range of observatory separation distances. A description of the observatory environment is provided along with protection for sensitive electronics to support operations in the harsh radiation belt environment. Spacecraft and subsystem key characteristics and instrument accommodations are included that allow the RBSP science objectives to be met.

Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes

“…These times of negative charging in sunlight present a unique situation. Extreme care was taken on the Van Allen Probes satellites to ensure a conducting spacecraft, and previous studies have shown, based on model results, that significant negative spacecraft charging should not occur in sunlight on a conducting spacecraft [Davis et al, 2012;Kirby et al, 2014]. In particular, we see from Figure 3 in the postmidnight sector at L > 4, there are a large number of negative spacecraft charging events, where hot electrons begin to gradient curvature drift eastward as they enter from the plasma sheet.…”

On the origin of low‐energy electrons in the inner magnetosphere: Fluxes and pitch‐angle distributions

“…Since the analysis in this paper is specifically aimed at low‐energy electrons, it is critical that surface charging on the spacecraft is low, that the effects from photoelectrons and secondaries are minimized, and that penetrating background radiation is mostly negligible, in order that the instrumentation reports fluxes based on the conditions in orbit. A large effort was made in the design of the satellite platform and in the choice of materials used in construction, in order to minimize the buildup of surface charge on the spacecraft, to prevent localized potential wells, and to inhibit the effects of penetrating background radiation [ Kirby et al , ]. This effort was supplemented by prelaunch environmental tests that demonstrated that the platform would have a very low susceptibility to surface charging once on orbit [ Kirby et al , ].…”

“…A large effort was made in the design of the satellite platform and in the choice of materials used in construction, in order to minimize the buildup of surface charge on the spacecraft, to prevent localized potential wells, and to inhibit the effects of penetrating background radiation [ Kirby et al , ]. This effort was supplemented by prelaunch environmental tests that demonstrated that the platform would have a very low susceptibility to surface charging once on orbit [ Kirby et al , ]. The level of spacecraft charging can be estimated from the Electric Fields and Waves (EFW) instrument on board Van Allen Probes [ Wygant et al , ].…”

Space Weather Operation at KASI With Van Allen Probes Beacon Signals

“…Generally, in South Korea, the antenna receives space weather data approximately 20% of the time. The data are transmitted to the ground via S‐band using 8 W solid‐state power amplifier transmitters (Kirby et al, ).…”