| Description: The mission_phase_name identifies a time period within the mission. |
| Namespace Id: vikinglander | Steward: geo | Class Name: Observation_Information | Type: ASCII_Short_String_Preserved |
| Minimum Value: None | Maximum Value: None | Minimum Characters: 1 | Maximum Characters: 255 |
| Unit of Measure Type: None | Default Unit Id: None | Attribute Concept: None | Conceptual Domain: SHORT_STRING |
| Status: Active | Nillable: false | Pattern: None |
| Permissible Value(s) | Value | Value Meaning |
| | Completion_Mission | Viking Lander 1 continued to operated in its automatic mode during the Completion Mission. The observation sequences were cyclic. VL1 returned via direct downlink image and meteorology data about once a week with image sequences repeating every 37 sols. The VL1 high-gain antenna was programmed to track the Earth until December, 1994. However, communications were lost in November 1982 after a command sequence uplink. Dates: 1980-08-07 to 1982-11-19. |
| | Continuation_Mission | Lander activities consisted of measurements by the imaging, meteorology, and XRFS instruments operating in a fully automated manner. Dates: 1978-05-31 to 1979-02-26. |
| | Extended_Mission | The Viking Extended Mission began after solar conjunction. The two lander spacecraft analyzed additional soil samples and dug three deep holes in the surface. All four spacecraft monitored the planet through the cycle of seasons. During the winter season, the landers operated in an automatic manner designed to allow the spacecraft to survive the cold temperatures and still return some data. Dates: 1976-11-15 to 1978-05-31. |
| | Interim_Period | The Interim Period mission phase occurred during the time of the Voyager 2 encounter with Jupiter. Thus, communications to and from the Viking spacecraft were limited. The landers continued to operate in an automated manner making imaging and meteorology observations. A final VL2 surface sampler sequence was conducted during this mission phase as an engineering test in the cold temperatures of mid winter. Dates: 1979-02-26 to 1979-07-19. |
| | Primary_Mission | The Viking Lander 1 spacecraft separated from the VO1 orbiter and descended to the Martian surface on July 20, 1976. The Viking Lander 2 spacecraft separated from the VO2 orbiter and descended to the Martian surface on September 3, 1976. The Primary Mission ended at the start of the solar conjunction in November 15, 1976. |
| | Survey_Mission | The plan for the landers was to collect image and meteorology data for as long as possible. Because VL2 no longer had a direct downlink capability, it meant that VL2 could return data only as long as VO1 provided a relay link, once every seven weeks. Communications with VL2 ended on April 11, 1980 after its batteries could no longer hold a charge. VL2 operated on the surface of Mars for 1281 sols. Dates: 1979-07-19 to 1980-08-07. |