CERTIFICATE OF RE-ENTRYOrbital Register™ · by Orbital Radar™
Entry no.
1970-0078
EXPLORER 1
EXPLORER 1 (NORAD 4) came down while still attached to its host on 31 March 1970, after 12 years, 1 month in orbit.
Official date
NORAD number
4
International designator
1958-001A
Object type
Spacecraft
Country
United States
Launched
1 Feb 1958Cape Canaveral
Re-entered (UTC)
31 Mar 1970UTC calendar day
Time in orbit
12 years, 1 month4,441 days
How it ended
Came down attached to its host
Latitude range
33.1°N to 33.1°SFinal inclination 33.1°
Mass
8 kg
Operator
ABMA / JPL
Built by
JPL
Bus
Explorer
Programme
Explorer ABMA
Where it came down
Latitude band its orbit allowedExact position not recorded
No position was recorded for this re-entry. Its final orbit, inclined at 33.1°, allowed a re-entry anywhere between 33.1°N and 33.1°S.
Life in orbit
12 years, 1 monthEXPLORER 1’s lowest and highest points above Earth, week by week, from its tracking history.
Also ended on 31 Mar 1970
1 entry
Entered in the Orbital Register™, founding volume, September 2026.
Record version 1 · No corrections · orbitalradar.com/register/1970-0078
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.
Record version 1 · No corrections · orbitalradar.com/register/1970-0078
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.