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🛰️ SATELLITE · HISTORICAL RECORD

P-11 No. 4426

Re-entered 26 Dec 1978

P-11 No. 4426 (NORAD 6931, COSPAR 1973-088C) was a US satellite that re-entered Earth's atmosphere on 26 Dec 1978, launched on 10 Nov 1973 on the HEXAGON SV-7 mission. It was operated by NRO / SAFSP as part of the EHH B programme. The spacecraft was built by LMSC/MOTO on the P-11 H bus, with a mass of 168 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.

1973
launched
1978
re-entered
5
years on orbit
168
kg mass

Lifecycle

Launched10 Nov 1973 · on the HEXAGON SV-7 mission
Operational26 Dec 1978 · entered service
Retired26 Dec 1978 · end of operational service
Re-entered26 Dec 1978 · atmospheric re-entry — object destroyed

Specifications

NORAD ID6931
COSPAR1973-088C
TypeSatellite
OperatorNRO / SAFSP
Country / StateUS
ManufacturerLMSC/MOTO
BusP-11 H
Mass168 kg
ProgrammeEHH B
CategorySIG
OrbitLEO (LLEO/S)
Altitude485 × 503 km
Inclination96.3°

Frequently asked questions

What happened to P-11 No. 4426?

P-11 No. 4426 re-entered Earth's atmosphere on 26 Dec 1978, ending a mission that began with its launch in 1973. 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. 4426 re-enter the atmosphere?

P-11 No. 4426 re-entered on 26 Dec 1978, according to Orbital Radar's historical catalogue records.

Who operated and built P-11 No. 4426?

P-11 No. 4426 was operated by NRO / SAFSP and built by LMSC/MOTO (US).

Launched together

HEXAGON SV-7Re-entered 1974
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.