CERTIFICATE OF RE-ENTRYOrbital Register™ · by Orbital Radar™
Entry no.
1974-0063
OPS 8520
OPS 8520 (NORAD 4406) re-entered Earth’s atmosphere on 8 March 1974, after 3 years, 9 months in orbit.
Official date
NORAD number
4406
International designator
1970-040B
Object type
Spacecraft
Country
United States
Launched
20 May 1970Vandenberg
Re-entered (UTC)
8 Mar 1974UTC calendar day
Time in orbit
3 years, 9 months1,388 days
How it ended
Re-entered (natural decay)
Latitude range
83.1°N to 83.1°SFinal inclination 83.1°
Mass
141 kg
Operator
NRO / SAFSP
Built by
LMSC / Cutler-Hammer/AIL
Bus
P-11 H
Programme
EHH B
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 83.1°, allowed a re-entry anywhere between 83.1°N and 83.1°S.
Life in orbit
3 years, 9 monthsOPS 8520’s lowest and highest points above Earth, week by week, from its tracking history.
Also ended on 8 Mar 1974
1 entryFrom the same launch
1970-040
Entered in the Orbital Register™, founding volume, September 2026.
Record version 1 · No corrections · orbitalradar.com/register/1974-0063
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.
Record version 1 · No corrections · orbitalradar.com/register/1974-0063
© 2026 Orbital Radar. Cite this entry by its number; the register itself may not be copied.