Viking 2 Orbiter

Viking 2

Agency

NASA

Country

🇺🇸 USA

Launched

1975-09-09

End Date

1978-07-25

Mass

883 kg (orbiter only)

Instruments

4 science instruments

Matching instrument suite to Viking 1 Orbiter: twin vidicon cameras, IRTM, MAWD

Orbit

Elliptical polar orbit; inclination raised to 75° to access higher latitudes

Key Findings

1.Imaged Utopia Planitia in detail to select the Viking 2 lander touchdown site
2.Obtained color global mosaic images used to create the first true-color map of Mars
3.Measured water vapor distribution across northern latitudes, revealing seasonal cycles
4.Provided continuous relay support for the Viking 2 lander throughout its surface mission

Mission Outcome

Viking 2 Orbiter operated from August 1976 to July 1978, complementing its sibling spacecraft by focusing on higher northern latitudes inaccessible to Viking 1. Its water-vapor measurements established the first quantitative baseline for Martian atmospheric science. A battery failure ended the mission on July 25, 1978.

Sources

[1] NASA NSSDCA — retrieved 2026-06-01
“Viking 2 Orbiter was inserted into Mars orbit on August 7, 1976. The spacecraft's mission was ended due to a battery failure on July 25, 1978.”

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