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ESO

Re-entered 10 Jul 1991

ESO (NORAD 21261, COSPAR 1990-104N) was a SU satellite that re-entered Earth's atmosphere on 10 Jul 1991, launched on 28 Nov 1990 on the Kol'tso No. 3L mission. It was operated by PVO as part of the ESO programme. The spacecraft was built by YUZH on the ESO bus, with a mass of 5 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.

1990
launched
1991
re-entered
1
year on orbit
5
kg mass

Lifecycle

Launched28 Nov 1990 · on the Kol'tso No. 3L mission
Operational28 Nov 1990 · entered service
Retired28 Nov 1990 · end of operational service
Re-entered10 Jul 1991 · atmospheric re-entry — object destroyed

Specifications

NORAD ID21261
COSPAR1990-104N
TypeSatellite
OperatorPVO
Country / StateSU
ManufacturerYUZH
BusESO
Mass5 kg
ProgrammeESO
CategoryCAL
OrbitLEO (LLEO/I)
Altitude498 × 521 km
Inclination82.5°

Frequently asked questions

What happened to ESO?

ESO re-entered Earth's atmosphere on 10 Jul 1991, ending a mission that began with its launch in 1990. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did ESO re-enter the atmosphere?

ESO re-entered on 10 Jul 1991, according to Orbital Radar's historical catalogue records.

Who operated and built ESO?

ESO was operated by PVO and built by YUZH (SU).

Launched together

Kol'tso No. 3LRe-entered 2000ESORe-entered 1992ESORe-entered 1992ESORe-entered 1992ESORe-entered 1992ESORe-entered 1992ESORe-entered 1992ESORe-entered 1993
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.