An international crew is readying for Thursday's planned launch of a NASA mission to the International Space Station after arriving at the Kennedy Space Center.

NASA's TRACERS (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites) mission is officially underway following a successful launch Wednesday at 2:13 p.m. EDT. The twin satellites rode a SpaceX Falcon 9 from Vandenberg Space Force Base in California.

Two NASA satellites rocketed into orbit from California aboard a SpaceX Falcon 9 rocket Wednesday, commencing a $170 million mission to study a phenomenon of space physics that has eluded researchers since the dawn of the Space Age.