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Van Allen Probe A (RBSP-A)



The Radiation Belt Storm Probes mission is part of NASA's Living With a Star Geospace program to explore fundamental processes that operate throughout the solar system, in particular those that generate hazardous space weather effects near the Earth and phenomena that could affect solar system exploration. RBSP is designed to help understand the sun's influence on the Earth and near-Earth space by studying the planet's radiation belts on various scales of space and time. Understanding the radiation belt environment and its variability has extremely important practical applications in the areas of spacecraft operations, spacecraft and spacecraft system design, mission planning, and astronaut safety.

The mission's science objectives are to: (1) discover which processes, singly or in combination, accelerate and transport radiation belt electrons and ions and under what conditions; (2) understand and quantify the loss of radiation belt electrons and determine the balance between competing acceleration and loss processes; and, (3) understand how the radiation belts change in the context of geomagnetic storms.

The instruments on the two RBSP spacecraft will provide the measurements needed to characterize and quantify the processes that produce relativistic ions and electrons. They will measure the properties of charged particles that comprise the Earth's radiation belts and the plasma waves that interact with them, the large-scale electric fields that transport them, and the magnetic field that guides them.

The spacecraft have an octagonal prism shape with a diameter of 1.8 m and a length of 1.3 m. Each carries four deployable solar samels to provide power and two S-band antennas for communications. Propulsion is provided by eight monopropellant (hydrazine) thrusters. The initial amount of available hydrazine for maneuvering is 56 kg.

RBSP-A has a mass of 591.6 kg, including 129.6 kg of instrumentation, exclusive of propellant. RBSP-B is slightly more massive at 610.6 kg as it carries mountings to which RBSP-A is attached at launch.

Alternate Names

  • 38752
  • RBSP-A
  • RBSP-A
  • Radiation Belt Storm Probe A

Facts in Brief

Launch Date: 2012-08-30
Launch Vehicle: Atlas V 401
Launch Site: Cape Canaveral, United States
Mass: 591.6 kg

Funding Agency

  • National Aeronautics and Space Administration (United States)


  • Space Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office

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