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Zenit-4 No. 51L

Re-entered 12 Oct 1968

Zenit-4 No. 51L (NORAD 3473, COSPAR 1968-087A) was a SU satellite that re-entered Earth's atmosphere on 12 Oct 1968, launched on 7 Oct 1968 on the Zenit-4 No. 51 mission. It was operated by TSUKOS as part of the Zenit-4 programme. The spacecraft was built by TSKBE3 on the Zenit-4 bus, with a mass of 2,200 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.

1968
launched
1968
re-entered
0
years on orbit
2,200
kg mass

Lifecycle

Launched7 Oct 1968 · on the Zenit-4 No. 51 mission
Operational12 Oct 1968 · entered service
Retired12 Oct 1968 · end of operational service
Re-entered12 Oct 1968 · atmospheric re-entry — object destroyed

Specifications

NORAD ID3473
COSPAR1968-087A
TypeSatellite
OperatorTSUKOS
Country / StateSU
ManufacturerTSKBE3
BusZenit-4
Mass2,200 kg
ProgrammeZenit-4
CategoryIMG
OrbitLEO (LLEO/I)
Altitude145 × 323 km
Inclination65.4°

Frequently asked questions

What happened to Zenit-4 No. 51L?

Zenit-4 No. 51L re-entered Earth's atmosphere on 12 Oct 1968, ending a mission that began with its launch in 1968. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did Zenit-4 No. 51L re-enter the atmosphere?

Zenit-4 No. 51L re-entered on 12 Oct 1968, according to Orbital Radar's historical catalogue records.

Who operated and built Zenit-4 No. 51L?

Zenit-4 No. 51L was operated by TSUKOS and built by TSKBE3 (SU).

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