RocketSTEM Issue #12 - July 2015 | Page 34

Dave Scott Al Worden Jim Irwin The leaning Falcon rests on on the lunar surface. Irwin took this photo at the start of the third EVA. Credit: NASA via Retro Space Images radioed, “that we checked off the 100-percent science completion square time during EVA-1 or maybe even shortly into EVA-2. From here on out, it’s gravy all the way!” The gravy of the third excursion would be tempered by the fact that it would also be the shortest, scheduled to last barely four and a half hours. It started with the recovery of a core sample from EVA-1. For a few moments, their efforts to extract the core tube from the ground were fruitless and Scott was almost ready to give up. However, with Irwin’s persuasion, both men hooked an arm under each handle of the drill and after several firm tugs the tube sprang from the ground. Precious minutes were wasted, though, when the vice carried on the rover to dismantle the tube into storable sections proved to have been 32 32 fitted backwards; Irwin broke out a wrench and used that, but Scott’s frustration was evident. He knew that for every minute wasted before the drive started, they would lose at least another two minutes of geological exploration. Some of the senior NASA managers in Mission Control wanted to abandon the core entirely. However, the astronauts and Joe Allen had an ally in Flight Director Gerry Griffin, who had shared several of their geological trips in the California mountains and knew how important the science was…and how important the deep core sample was to the success of this mission. It was he who persuaded the managers not to abandon the core tube work. After they had partially disassembled the tube, it was decided that they should leave the remainder of the task to later. When the core was finally opened on Earth, it proved to contain several dozen layers which documented some 400 million years’ worth of lunar history... At length, Scott and Irwin buckled into the rover and headed westnorthwest for a good look at Hadley Rille. After the rille, if time permitted, they hoped to grab an opportunity to inspect the mysterious “North Complex” of craters, which some geologists thought might be a cluster of small, ancient volcanoes. Their arrival at Hadley Rille was truly breathtaking. Its far wall, bathed in the harsh, direct sunlight of the late lunar morning, showed distinct layers of rock pushing through a mantle of dust, lending credence to theories that Mare Imbrium had been built up as a succession of ancient lava flows. One theory was that the rille was www.RocketSTEM .org