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ERS 21

Retired 1968

ERS 21 (NORAD 3430, COSPAR 1968-081C) is a retired US satellite, withdrawn from service around 30 Sep 1968, launched on 26 Sep 1968 on the OV2-5 mission. It was operated by SAMSO as part of the ORS III programme. The spacecraft was built by TRW on the ORS bus, with a mass of 13 kg. Historical record from Orbital Radar's satellite archive, cross-referenced with the live satellite catalogue.

1968
launched
1968
retired
58
years on orbit
13
kg mass

Lifecycle

Launched26 Sep 1968 · on the OV2-5 mission
Operational30 Sep 1968 · entered service
Retired30 Sep 1968 · end of operational service
StatusOn orbit (not live-tracked)

Specifications

NORAD ID3430
COSPAR1968-081C
TypeSatellite
OperatorSAMSO
Country / StateUS
ManufacturerTRW
BusORS
Mass13 kg
ProgrammeORS III
CategoryTECH
OrbitGEO (GEO/I)
Altitude35,765 × 35,822 km
Inclination13.6°

Frequently asked questions

What happened to ERS 21?

ERS 21 was retired from service around 30 Sep 1968 after launching in 1968. It is no longer operational but remains catalogued.

Who operated and built ERS 21?

ERS 21 was operated by SAMSO and built by TRW (US).

Launched together

OV2-5NORAD 3428ERS 28Re-entered 1971LES 6NORAD 3431
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.