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AD-B

Re-entered 18 Oct 1968

AD-B (NORAD 931, COSPAR 1964-076A) was a US satellite that re-entered Earth's atmosphere on 18 Oct 1968, launched on 21 Nov 1964 on the AD-B mission. It was operated by LARCN as part of the Explorer AD programme. The spacecraft was built by SCHJ on the 12' Sphere bus, with a mass of 8 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.

1964
launched
1968
re-entered
4
years on orbit
8
kg mass

Lifecycle

Launched21 Nov 1964 · on the AD-B mission
Operational18 Oct 1968 · entered service
Retired18 Oct 1968 · end of operational service
Re-entered18 Oct 1968 · atmospheric re-entry — object destroyed

Specifications

NORAD ID931
COSPAR1964-076A
TypeSatellite
OperatorLARCN
Country / StateUS
ManufacturerSCHJ
Bus12' Sphere
Mass8 kg
ProgrammeExplorer AD
CategorySCI
OrbitLEO (LEO/I)
Altitude542 × 2,480 km
Inclination81.3°

Frequently asked questions

What happened to AD-B?

AD-B re-entered Earth's atmosphere on 18 Oct 1968, ending a mission that began with its launch in 1964. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did AD-B re-enter the atmosphere?

AD-B re-entered on 18 Oct 1968, according to Orbital Radar's historical catalogue records.

Who operated and built AD-B?

AD-B was operated by LARCN and built by SCHJ (US).

Launched together

Injun 4NORAD 932
Historical record from the Orbital Radar satellite archive. Sources & methodology: data sources. Accessed 2026-09-06.