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🛰️ SATELLITE · HISTORICAL RECORD

P-11 No. 4421

Re-entered 8 Mar 1974

P-11 No. 4421 (NORAD 4406, COSPAR 1970-040B) was a US satellite that re-entered Earth's atmosphere on 8 Mar 1974, launched on 20 May 1970 on the CORONA CR-11 mission. It was operated by NRO / SAFSP as part of the EHH B programme. The spacecraft was built by LMSC/CHAIL on the P-11 H bus, with a mass of 141 kg. Like most satellites in low orbits, it was gradually slowed by atmospheric drag until re-entry. Historical record from Orbital Radar's satellite archive, cross-referenced with the live satellite catalogue.

1970
launched
1974
re-entered
4
years on orbit
141
kg mass

Lifecycle

Launched20 May 1970 · on the CORONA CR-11 mission
Operational22 Jan 1973 · entered service
Retired22 Jan 1973 · end of operational service
Re-entered8 Mar 1974 · atmospheric re-entry — object destroyed

Specifications

NORAD ID4406
COSPAR1970-040B
TypeSatellite
OperatorNRO / SAFSP
Country / StateUS
ManufacturerLMSC/CHAIL
BusP-11 H
Mass141 kg
ProgrammeEHH B
CategorySIG
OrbitLEO (LLEO/I)
Altitude488 × 496 km
Inclination83.1°

Frequently asked questions

What happened to P-11 No. 4421?

P-11 No. 4421 re-entered Earth's atmosphere on 8 Mar 1974, ending a mission that began with its launch in 1970. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did P-11 No. 4421 re-enter the atmosphere?

P-11 No. 4421 re-entered on 8 Mar 1974, according to Orbital Radar's historical catalogue records.

Who operated and built P-11 No. 4421?

P-11 No. 4421 was operated by NRO / SAFSP and built by LMSC/CHAIL (US).

Launched together

CORONA CR-11Re-entered 1970
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.