I2M No. 312

Re-entered 8 Mar 1980

I2M No. 312 (NORAD 4590, COSPAR 1970-087A) was a SU satellite that re-entered Earth's atmosphere on 8 Mar 1980, launched on 20 Oct 1970 on the IS-M mission. It was operated by PKO as part of the IS 5V91 programme. The spacecraft was built by TSKBM/KB1 on the IS bus, with a mass of 3,300 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.

1970

launched

1980

re-entered

years on orbit

3,300

kg mass

Lifecycle

Launched20 Oct 1970 · on the IS-M mission

Operational1 Nov 1970 · entered service

Retired1 Nov 1970 · end of operational service

Re-entered8 Mar 1980 · atmospheric re-entry — object destroyed

Specifications

NORAD ID4590

COSPAR1970-087A

TypeSatellite

OperatorPKO

Country / StateSU

ManufacturerTSKBM/KB1

BusIS

Mass3,300 kg

ProgrammeIS 5V91

CategoryTARG

OrbitLEO (LLEO/I)

Altitude452 × 566 km

Inclination62.9°

Frequently asked questions

What happened to I2M No. 312?

I2M No. 312 re-entered Earth's atmosphere on 8 Mar 1980, ending a mission that began with its launch in 1970. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did I2M No. 312 re-enter the atmosphere?

I2M No. 312 re-entered on 8 Mar 1980, according to Orbital Radar's historical catalogue records.

Who operated and built I2M No. 312?

I2M No. 312 was operated by PKO and built by TSKBM/KB1 (SU).

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

Browse the live satellite directory → Re-entered satellites archive → Launch record: IS-M → What is space debris? →