Thor Delta C | Explorer 21

Explorer 21 (IMP 2) was a solar-cell and chemical-battery powered spacecraft instrumented for interplanetary and distant magnetospheric studies of energetic particles, cosmic rays, magnetic fields, and plasmas.

Mission Details

  • Launch date: October 4, 1964 at 03:45 AM UTC
  • Launch vehicle: Thor Delta C
  • Operator: United States Air Force
  • Launch site: Cape Canaveral SFS, FL, USA
  • Mission type: Astrophysics