CERTIFICATE OF RE-ENTRYOrbital Register™ · by Orbital Radar™
Entry no.
1966-0025
EXPLORER 21 (IMP-2)
EXPLORER 21 (IMP-2) (NORAD 889) re-entered Earth’s atmosphere on 30 January 1966, after 1 year, 3 months in orbit.
Official date
NORAD number
889
International designator
1964-060A
Object type
Spacecraft
Country
United States
Launched
4 Oct 1964Cape Canaveral
Re-entered (UTC)
30 Jan 1966UTC calendar day
Time in orbit
1 year, 3 months483 days
How it ended
Re-entered (natural decay)
Latitude range
—
Mass
62 kg
Operator
GSFC
Built by
GSFC
Bus
IMP
Programme
IMP
Where it came down
Not on recordNo position was recorded for this re-entry. Its final orbit is not on record.
Life in orbit
1 year, 3 monthsEXPLORER 21 (IMP-2)’s lowest and highest points above Earth, week by week, from its tracking history.
Also ended on 30 Jan 1966
2 entries
Entered in the Orbital Register™, founding volume, September 2026.
Record version 1 · No corrections · orbitalradar.com/register/1966-0025
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.
Record version 1 · No corrections · orbitalradar.com/register/1966-0025
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.