Explorer 21 IMP-II second Interplanetary Monitoring Platform spacecraft family
Second Interplanetary Monitoring Platform spacecraft, Explorer XXI was launched on 4 October 1964 to study cislunar radiation, the interplanetary magnetic field, solar-wind interactions, and solar-terrestrial relationships; despite falling short of its planned apogee, it returned useful magnetosphere data.
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Identity
- Aliases
- Explorer 21Explorer XXIIMP-BIMP-IIIMP-2Interplanetary Monitoring Platform-2
- Family Name
- Explorer 21
- Full Name
- Explorer 21 IMP-II second Interplanetary Monitoring Platform spacecraft family
- Roles
- orbiterinterplanetary_probeobservatoryresearch
- Status
- retired
- Type
- spacecraft
Details
- Description
- Second Interplanetary Monitoring Platform spacecraft, Explorer XXI was launched on 4 October 1964 to study cislunar radiation, the interplanetary magnetic field, solar-wind interactions, and solar-terrestrial relationships; despite falling short of its planned apogee, it returned useful magnetosphere data.
- First Flight Year
- 1,964
- Last Flight Year
- 1,966
- Operator
Links
- Official Url
- https://ntrs.nasa.gov/citations/19650022994
Assets & Meta
- Creation Time
- August 13, 2026 at 13:20:57 UTC
- Updated Time
- August 14, 2026 at 15:34:35 UTC