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🛰️ SATELLITE · HISTORICAL RECORD

ERS 31

Re-entered 19 Sep 1979

ERS 31 (NORAD 3534, COSPAR 1968-100B) was a US satellite that re-entered Earth's atmosphere on 19 Sep 1979, launched on 8 Nov 1968 on the Pioneer D mission. It was operated by GSFC as part of the TTS programme. The spacecraft was built by TRW on the ORS bus, with a mass of 18 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
1979
re-entered
11
years on orbit
18
kg mass

Lifecycle

Launched8 Nov 1968 · on the Pioneer D mission
Operational1 Dec 1968 · entered service
Retired1 Dec 1968 · end of operational service
Re-entered19 Sep 1979 · atmospheric re-entry — object destroyed

Specifications

NORAD ID3534
COSPAR1968-100B
TypeSatellite
OperatorGSFC
Country / StateUS
ManufacturerTRW
BusORS
Mass18 kg
ProgrammeTTS
CategoryCAL
OrbitLEO (LEO/I)
Altitude379 × 934 km
Inclination32.9°

Frequently asked questions

What happened to ERS 31?

ERS 31 re-entered Earth's atmosphere on 19 Sep 1979, 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 ERS 31 re-enter the atmosphere?

ERS 31 re-entered on 19 Sep 1979, according to Orbital Radar's historical catalogue records.

Who operated and built ERS 31?

ERS 31 was operated by GSFC and built by TRW (US).

Launched together

Pioneer DRe-entered 1968
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.