Pioneer Venus Orbiter

Pioneer Venus Orbiter
Artist's impression of Pioneer 12 in orbit above Venus
NamesPioneer Venus 1
Pioneer 12
Mission typeVenus orbiter
OperatorNASA / Ames
COSPAR ID1978-051A
SATCAT no.10911
Websitescience.nasa.gov
Mission durationTotal:
14 years, 4 months and 18 days
Science phase:
13 years, 10 months and 4 days
Spacecraft properties
BusHS-507
ManufacturerHughes
Launch mass582 kg (1,283 lb)
Dry mass517 kg (1,140 lb)
Dimensions2.5 × 2.5 × 1.2 m (8.2 × 8.2 × 3.9 ft)
Power312 watts
Start of mission
Launch dateMay 20, 1978, 13:13:00 (1978-05-20UTC13:13Z) UTC
RocketAtlas SLV-3D Centaur-D1AR (AC-50)
Launch siteCape Canaveral LC-36A
End of mission
DisposalDecommissioned
Last contactOctober 8, 1992, 19:22 (1992-10-08UTC19:23Z) UTC
Decay dateOctober 22, 1992
Orbital parameters
Reference systemCytherocentric
Semi-major axis33,405.8 km (20,757.4 mi)
Eccentricity0.842
Pericytherion altitude181.6 km (112.8 mi)
Apocytherion altitude66,630 km (41,400 mi)
Inclination105 degrees
Period24 hours
Epoch22 November 1979, 11:53:20 UTC
Venus orbiter
Orbital insertionDecember 4, 1978

The Pioneer Venus Orbiter, also known as Pioneer Venus 1 or Pioneer 12, was a mission to Venus conducted by NASA as part of the Pioneer Venus project. Launched in May 1978 atop an Atlas-Centaur rocket, the spacecraft was inserted into an elliptical orbit around Venus on December 4, 1978. It returned data from Venus until October 1992.

The spacecraft conducted radar altimetry observations allowing the first global topographic map of the Venusian surface to be constructed.