SO-M No. 504

Re-entered 22 Dec 1975

SO-M No. 504 (NORAD 8510, COSPAR 1975-122A) was a SU satellite that re-entered Earth's atmosphere on 22 Dec 1975, launched on 22 Dec 1975 on the SO-M No. 504 mission. It was operated by IKI / BABTS as part of the SO-M programme. The spacecraft was built by NPOL on the SO-M bus, with a mass of 905 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

years on orbit

905

kg mass

Lifecycle

Launched22 Dec 1975 · on the SO-M No. 504 mission

Operational25 Mar 1976 · entered service

Retired25 Mar 1976 · end of operational service

Re-entered22 Dec 1975 · atmospheric re-entry — object destroyed

Specifications

NORAD ID8510

COSPAR1975-122A

TypeSatellite

OperatorIKI / BABTS

Country / StateSU

ManufacturerNPOL

BusSO-M

Mass905 kg

ProgrammeSO-M

CategoryAST

OrbitLEO (LLEO/I)

Altitude231 × 464 km

Inclination65.0°

Frequently asked questions

What happened to SO-M No. 504?

SO-M No. 504 re-entered Earth's atmosphere on 22 Dec 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 SO-M No. 504 re-enter the atmosphere?

SO-M No. 504 re-entered on 22 Dec 1975, according to Orbital Radar's historical catalogue records.

Who operated and built SO-M No. 504?

SO-M No. 504 was operated by IKI / BABTS and built by NPOL (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: SO-M No. 504 → What is space debris? →