The two Radiation Belt Storm Probes (RBSP) spacecraft slated to launch in August aboard a United Launch Alliance Atlas 5 rocket arrived May 1 at NASAโ€™s Kennedy Space Center in Florida to begin a two-year mission to study the extremes of space weather.

The twin RBSP left the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Md., in custom-made shipping containers April 30 and were flown from Andrews Air Force Base to Kennedy in a U.S. Air Force C-17 cargo plane. Over the next several weeks, APL engineers and scientists will prepare RBSP for launch.

APL built the probes under a $500 million cost-plus contract awarded in 2006. Late deliveries of several instruments due to design and parts related issues prompted NASA last summer to delay the missionโ€™s launch readiness date from May 2012 to September 2012. Launch is slated for Aug. 23.