NASA has renamed two satellites launched in August for James Van Allen, a pioneering astrophysicist who discovered the radiation belts surrounding Earth.

Artist's concept of the Van Allen Probes and Earth's radiation belts. Credit: NASA
 
Formerly known as the Radiation Belt Storm Probes, the Van Allen Probes began their two-year science mission Oct. 28 after a 60-day commissioning phase.

The Van Allen Probes are investigating what causes Earth's donut-shaped radiation belts to swell and contract as solar storms erupt and propagate through space.

Magnetic storms in the radiation belts can pose threats to communications and navigation satellites, along with astronauts in orbit.

The $686 million mission is designed to simultaneously sample the radiation belts from two different locations, giving scientists data on how the environment changes with space and time.

James Van Allen is credited with the 1958 discovery of the radiation belts using Explorer 1, the first successful U.S. satellite.

"James Van Allen was a true pioneer in astrophysics," said John Grunsfeld, astronaut and associate administrator for NASA's science mission directorate. "His ground breaking research paved the way for current and future space exploration. These spacecraft now not only honor his iconic name but his mark on science."

Van Allen was principal investigator for scientific investigations on 24 Earth satellites and planetary missions, including Pioneer 10 and Pioneer 11.

File photo of the launch of the Van Allen Probes from Cape Canaveral, Fla. Credit: Stephen Clark/Spaceflight Now
 
The Van Allen Probes were built at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. Van Allen, who died in 2006, worked at the lab during and after World War II, according to an APL press release.

"After only two months in orbit, the Van Allen Probes have made significant contributions to our understanding of the radiation belts," said Ralph Semmel, director of APL. "The science and data from these amazing twin spacecraft will allow for more effective and safe space technologies in the decades to come. APL is proud to have built and to operate this new resource for NASA and our nation, and we are proud to have the mission named for one of APL's original staff."

Each Van Allen Probe carries five instruments to detect particles, magnetic fields and plasma waves in the radiation belts. The satellites launched together Aug. 30 aboard a United Launch Alliance Atlas 5 rocket, and they operate at altitudes between 375 miles and 19,000 miles above Earth.

"We are very pleased to have the Van Allen Probes successfully complete the commissioning period," said Kim Cooper, Van Allen Probes project manager at APL. "Over the past 60 days, the many complex systems on the probes have come to life and started to work together. The spacecraft's science instrument teams are already recording illuminating data, and they are taking advantage of their best understanding of the mechanics and properties of the radiation belts to date."