8/8/2019 Viking Lander Sterilization

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ANDAUNCH

MISSION OPERATIONS

STATUS BULLETIN

No. 7

June 23, 1975

The first of the two Viking landers being moved into the sterilization chamberat Kennedy Space Center. The lander portions of the Viking spacecraft are

sterilized by swirling clouds of heated nitrogen gas at a temperature of approx-imq.-tely 235°F for 40 hours. The sterilization process is designed to prevent

contamination of the life- seeking experiments on the lander as well as protectthe Martian surface from living organisms from the Earth.

(More details on other side.)

8/8/2019 Viking Lander Sterilization

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The Viking VLC-2 Lander successfully completed its all-important sterilizationcycle late last week and has completed its Post Sterilization Short Test to verifythat all subsystems are functioning properly. A number of minor anomaliesoccurred during this testing; some are understood and others are being investi-gated. Overall confidence is high that the Lander is in good shape.

While the post-sterilization testing was being conducted, the VLC-l Lander wasmoved into the sterilization chamber and readied for its testing. However, aprogram constraint stipulated that heating could not begin until a certain numberof post- sterilization tests were successfully completed on VLC -2. This beingaccomplished, VLC -1 began its sterilization cycle on June 20. The baking wascompleted on June 22 and post- sterilization testing is expected to start on thisunit today.

On the Orbiter side, all formal system testing was completed on VO-l and themove to ESA-60 for final flight preparations is now scheduled for June 30.VO-2 was placed on the transporter and was mated with the spacecraft adapter;this adapter is the tubular trusswork that mounts the Orbiter/Lander ass"embly

on top of the Titan III-D launch vehicle. Following some special relay radiotests, the unit will be moved to SAEF-2 on June 26, where it will be preparedfor final mating with VLC-2.

System level flight operations test and training continued with the series ofverification tests. VT-3 was run successfully on June 12 and checked out thesegment of the mission that included the launch of Spacecraft B while Space-craft A is in the cruise mode. All verification tests up to this point were classi-fied as "Short-Loop, I' in that the data, commands, etc., never went outside

the SFOF. VT-4, however, did require data exchanges between JPL and thetracking stations at both the Goldstone and Spain locations. This test, success-fully run from June 13 through June 20, checked out the design and execution ofa Spacecraft B midcourse maneuver, while Spacecraft A remained in cruise.

During the period covering June lO-lB, the Veep ~pace Network ran a series often successful Operational Verification Tests on the 26-meter antennas atGoldstone, Spain and Australia.