NRL PL170C

Re-entered 7 Jan 1990

NRL PL170C (NORAD 4963, COSPAR 1971-012E) was a US satellite that re-entered Earth's atmosphere on 7 Jan 1990, launched on 17 Feb 1971 on the DAPP Block 5A F-3 mission. It was operated by NRL as part of the NRL Cal programme. The spacecraft was built by NRL on the NRL 10" bus, with a mass of 1 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.

1971

launched

1990

re-entered

years on orbit

kg mass

Lifecycle

Launched17 Feb 1971 · on the DAPP Block 5A F-3 mission

Operational17 Feb 1971 · entered service

Retired17 Feb 1971 · end of operational service

Re-entered7 Jan 1990 · atmospheric re-entry — object destroyed

Specifications

NORAD ID4963

COSPAR1971-012E

TypeSatellite

OperatorNRL

Country / StateUS

ManufacturerNRL

BusNRL 10"

Mass1 kg

ProgrammeNRL Cal

CategoryCAL

OrbitLEO (LEO/S)

Altitude771 × 830 km

Inclination98.8°

Frequently asked questions

What happened to NRL PL170C?

NRL PL170C re-entered Earth's atmosphere on 7 Jan 1990, ending a mission that began with its launch in 1971. Objects in low orbits are gradually slowed by atmospheric drag until they fall back and burn up on re-entry.

When did NRL PL170C re-enter the atmosphere?

NRL PL170C re-entered on 7 Jan 1990, according to Orbital Radar's historical catalogue records.

Who operated and built NRL PL170C?

NRL PL170C was operated by NRL and built by NRL (US).

Launched together

DMSP Block 5A F-3NORAD 4953 NRL PL170ARe-entered 1989 NRL PL170BRe-entered 1989

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: DAPP Block 5A F-3 → What is space debris? →