[317] With site selection behind them, the landing site working group members faced two more tasks-completing their individual commitments to science teams and certifying the Martian landing areas they had chosen. They were reasonably hopeful that the targets were safe ones, but they could be certain only after they had examined additional Earth-based radar studies and the orbital pictures Viking 1 would send back from Mars. Careful certification of each Viking site would have to be carried out before the landers descended to the Martian surface, but no one expected certification to pose real difficulties now that they were over the hurdle of finding suitable targets. These expectations would be dashed in June 1975.
[327]....cruise, lander and orbiter science instruments were prepared and calibrated for Mars operations. 17
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.....actuation commands from Earth, and some transient communications difficulties had to be corrected But most significant for the Landing Site Staff, the sampler arm on the lander had stuck on the third day of the landed mission (sol 3). Although the Viking team was able to diagnose the difficulty, devise and test a solution, and free the sampler boom assembly in time to collect soil samples on schedule (sol 8), the problem emphasized the importance of safely landing Viking 2 . Simply put, if Viking 1 failed, then no chances could be taken in choosing a landing site for the second mission. All the tension and pressure experienced during the past month reappeared. 57
B-3 East |
alpha |
47.2°N lat. |
224.9° long. |
B-3 East |
beta |
48.0°N |
228.0° |
B-2 West |
I |
44. 1°N |
154.9° |
B-2 West |
II |
47.3°N |
156.6° |
B-2 West |
III |
43.5°N |
153.0° 67 |
At 3:58:20 p.m. PDT (9:49:05 am. local Mars time) on 3 September 1976, the second lander touched down safely. Cheers mixed with sighs of relief, though the crisis was not over yet. The Deep Space Network worked with the flight team to get the proper commands to the orbiter. Once the spacecraft locked back onto its celestial reference point-the star Vega-Earth control again began to recover mission data, including the first two photographs taken by the lander's cameras immediately after the craft had reached the Martian surface. 71
** If the pressure was as high as 7.8 millibars the temperature rose above freezing, liquid water was possible at Cydonia.