The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland., will develop and operate twin NASA spacecraft to study how the sun interacts with Earth's radiation belts.
Part of NASA's Living With a Star Program, the Radiation Belt Storm Probes (RBSP) will study the Van Allen belts, the doughnut-shaped bands of charged particles trapped by Earth's magnetic field that extend some 20,000 miles around our planet.

Space Scientists Uncover Causes Of Gap In Van Allen Belts

London UK (SPX) Sep 27, 2006

A team of British and US scientists have discovered that the gap in the Van Allen radiation belts is formed by natural wave turbulence in space, not by lightning. The discovery settles years of controversy among space scientists about the mechanisms responsible for causing the gap and has important implications for space weather forecasting.

http://www.spacedaily.com/reports/Space_Sc..._Belts_999.html

Final preparations have begun for launch on Thursday, Aug. 23, from Florida's Space Coast.

The press briefing was held yesterday, with media archived here:
http://www.nasa.gov/mission_pages/rbsp/mul..._materials.html

Delayed till Thursday the 30th due to TS/Hurricane Isaac according to spaceflightnow.com:

http://www.spaceflightnow.com/atlas/av032/status.html

Launched and in orbit!