Viking 1 Orbiter

Viking 1

Agency

NASA

Country

🇺🇸 USA

Launched

1975-08-20

End Date

1980-08-17

Mass

883 kg (orbiter only)

Instruments

4 science instruments

Two vidicon cameras (IRTM), infrared thermal mapper, Mars atmospheric water detector (MAWD), entry science

Orbit

Elliptical polar orbit, 300 × 33,000 km, evolved over mission lifetime

Key Findings

1.Mapped 97% of the Martian surface at 200–300 m resolution — the first near-complete photographic atlas
2.Imaged and confirmed the Viking 1 lander site in Chryse Planitia through high-resolution reconnaissance
3.Discovered extensive evidence of ancient fluvial channels, outflow valleys, and possible shorelines
4.Monitored two major dust storms in 1977 from orbit, correlating atmospheric opacity with surface conditions

Mission Outcome

Viking 1 Orbiter operated for four years, far exceeding its design life of 120 days. It served simultaneously as a relay station for the Viking 1 lander and as an independent science platform mapping the Martian surface and atmosphere. Operations ended August 17, 1980, when the last propellant was exhausted.

Sources

[1] NASA NSSDCA — retrieved 2026-06-01
“Viking 1 Orbiter was inserted into Mars orbit on June 19, 1976 and operated until August 17, 1980, returning thousands of images of the Martian surface.”

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