Explorer-1 [Prime], also known as E1P and Electra,[1] was a CubeSat-class picosatellite built by the Space Science and Engineering Laboratory (SSEL)[2] at Montana State University.
It was launched aboard a Taurus-XL rocket from Vandenberg Air Force Base, California on 4 March 2011,[3] but failed to achieve orbit after the rocket malfunctioned.
As part of NASA's ELaNA[4] program, E1P was to be launched along with NASA's Glory satellite,[5] the Kentucky Space KySat-1 and the University of Colorado Boulder Hermes CubeSats.
[6] E1P was a re-flight mission of Explorer 1, the first American satellite, using modern technology including a Geiger tube donated by James Van Allen.
[9] The Michigan Exploration Laboratory (MXL) suspects that the M-Cubed CubeSat, a joint project run by MXL and JPL, became magnetically conjoined to Explorer-1 Prime Unit 2, a second CubeSat released at the same time, via strong onboard magnets used for passive attitude control (see: Magnetorquer), after deploying on October 28, 2011.