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🛰️ SATELLITE · HISTORICAL RECORD

UK 4

Re-entered 12 Dec 1978

UK 4 (NORAD 5675, COSPAR 1971-109A) was a UK satellite that re-entered Earth's atmosphere on 12 Dec 1978, launched on 11 Dec 1971 on the UK 4 mission. It was operated by SRC as part of the UK programme. The spacecraft was built by BAC on the UK 4 bus, with a mass of 103 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.

1971
launched
1978
re-entered
7
years on orbit
103
kg mass

Lifecycle

Launched11 Dec 1971 · on the UK 4 mission
Operational12 Dec 1978 · entered service
Retired12 Dec 1978 · end of operational service
Re-entered12 Dec 1978 · atmospheric re-entry — object destroyed

Specifications

NORAD ID5675
COSPAR1971-109A
TypeSatellite
OperatorSRC
Country / StateUK
ManufacturerBAC
BusUK 4
Mass103 kg
ProgrammeUK
CategorySCI
OrbitLEO (LLEO/I)
Altitude473 × 590 km
Inclination83.0°

Frequently asked questions

What happened to UK 4?

UK 4 re-entered Earth's atmosphere on 12 Dec 1978, ending a mission that began with its launch in 1971. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did UK 4 re-enter the atmosphere?

UK 4 re-entered on 12 Dec 1978, according to Orbital Radar's historical catalogue records.

Who operated and built UK 4?

UK 4 was operated by SRC and built by BAC (UK).

Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.