Guidance And Control Subsystem

During the initial landed operations (the 5 minutes or so following touchdown), all guidance and control components except the GCSC were powered down and remained off for the remainder of the landed mission. The GCSC was the brains of the Lander, controlling all events and receiving frequent software updates from the Earth-based flight team. Although prelaunch and cruise operations had indicated that both GCSC A and B on each Lander were completely functional, GCSC A was arbitrarily selected...

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Altimeter Structure

Figure 1-5 Lander Base Cover and Mortar Truss Figure 1-5 Lander Base Cover and Mortar Truss Figure 1-6 Lander Body Equipment Plate, Top View Figure 1-6 Lander Body Equipment Plate, Top View RTG Power Source (2 Eal (Inside Cover) Terminal Descent Propellant Tank (2 Ea) Radar Altimeter Antenna & Terminal Descent Landing Radar (Underside of Lander Structure) RTG Power Source (2 Eal (Inside Cover) Radar Altimeter Antenna & Terminal Descent Landing Radar (Underside of Lander Structure) 450,000...

Separation Through Landing Phase

During this phase, the Lander engineering hardware was called upon to perform in a very exacting manner, in some cases for the first and last time as an element of the Viking Lander. The entry science was initiated and performed the entry investigations, and shortly after landing, camera 2 was activated and the landed science investigations were begun. This chapter describes Lander subsystem performance during this most critical mission phase. This performance was extracted from realtime and...

Gcsc

Figure IV-3 Lander Component Operation during Preseparation Checkout Not only did this verify both azimuth and elevation scanning, but analysis of the pin light intensity was a check on any outgassing product condensation on the camera's external window since launch. The camera diodes were checked by an internal calibration sequence that consisted of exposing the cameras' 12 diodes to an internal pinlight and checking 11 of the 12 diodes' response and noise level. The twelfth diode, designed...

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Figure 1-9 Lander Functional Block Diagram The GCSC memory contains the software (flight program) that provides the capability to control Lander functions from prelaunch through the duration of the landed mission. The flight program consists of an operating system known as the flight executive and a set of user application programs to control specific mission phases operations. The flight program is redundant in that it resides in both sides of the GCSC. However, these sides are independent of...

Viking Mission Plan

Two identical Viking spacecraft, each consisting of an Orbiter and a Lander, were launched from Kennedy Space Center on a Titan III, Centaur from Launch Complex 41. Viking 1 (Orbiter 1 Lander 1) was launched August 20, 1975 and Viking 2 (Orbiter 2 Lander 2) was launched September 9, 1975. With a second firing of the Centaur engine the Vikmg spacecraft were injected into trans-Mars trajectories. Just after the cruise to Mars began, the spacecraft separated from the Centaur, and the Orbiters then...

UAMS

Instrument turned on for 30 minutes (20-minute warm up, 10-minutes data collection), format 2A. Collected mass scans on residual gases in the analyzer plus engineering data. 2 samples sec for duration of format 3. 1 sample sec for 10 minutes, format 2A. 1 sample sec for 10 minutes, format 2A. 1 sample sec for 10 minutes, format 2A. 6. Relay Communications Equipment (RCE) Module The RCE test was a verification of the capability to transmit data via the relay link from the Lander to the Orbiter....

Introduction And Scope

This report summarizes Viking Lander hardware performance during launch, interplanetary cruise, Mars orbit insertion, pre separation, separation through landing, and the primary landed mission. The primary empTiasis is on Lander engineering and science hardware operations, not the results of the scientific investigations conducted during the mission phases. The Viking Lander science results are reported in the June 1977 issue of The Journal of Geophysical Research. Detailed information...

Viking Lander Configuration

Apollo Capsule

Figure 1-3 is an exploded view of the Viking Lander capsule. The Lander is doubly encapsulated within the bioshield and the descent capsule. The bioshield, the two-piece outer capsule, consists of a base and cap which protects the sterilized descent capsule from biological, chemical, and particulate contamination before and during launch. The bioshield cap was jettisoned shortly after launch. In Mars orbit, the descent capsule separates from the bioshield base. The descent capsule consists of...