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Nauka 5KSA No. 2

Re-entered 10 Apr 1975

Nauka 5KSA No. 2 (NORAD 7721, COSPAR 1975-020F) was a SU satellite that re-entered Earth's atmosphere on 10 Apr 1975, launched on 26 Mar 1975 on the Zenit-2M mission. It was operated by TSSKB as part of the Nauka 5KS programme. The spacecraft was built by TSSKB on the Nauka bus, with a mass of 630 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.

1975
launched
1975
re-entered
0
years on orbit
630
kg mass

Lifecycle

Launched26 Mar 1975 · on the Zenit-2M mission
Operational6 Apr 1975 · entered service
Retired6 Apr 1975 · end of operational service
Re-entered10 Apr 1975 · atmospheric re-entry — object destroyed

Specifications

NORAD ID7721
COSPAR1975-020F
TypeSatellite
OperatorTSSKB
Country / StateSU
ManufacturerTSSKB
BusNauka
Mass630 kg
ProgrammeNauka 5KS
CategorySCI
OrbitLEO (LLEO/I)
Altitude194 × 215 km
Inclination81.3°

Frequently asked questions

What happened to Nauka 5KSA No. 2?

Nauka 5KSA No. 2 re-entered Earth's atmosphere on 10 Apr 1975, ending a mission that began with its launch in 1975. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did Nauka 5KSA No. 2 re-enter the atmosphere?

Nauka 5KSA No. 2 re-entered on 10 Apr 1975, according to Orbital Radar's historical catalogue records.

Who operated and built Nauka 5KSA No. 2?

Nauka 5KSA No. 2 was operated by TSSKB and built by TSSKB (SU).

Launched together

Gektor No. 59LRe-entered 1975
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.