Skylab 2: Difference between revisions

| title = Days in Spacespace

The [[Skylab]] station suffered significant damage on its May 14 launch: its micrometeorite shield, and one of its primary [[Photovoltaic module|solar array]]s had torn loose during launch, and the remaining primary solar array was jammed. Without the shield which was designed to also provide thermal protection, Skylab baked in the Sun, and rising temperatures inside the workshop released toxic materials into the station's atmosphere and endangered on-board film and food. The first crew was supposed to launch on May 15, but instead had to train practicing repair techniques as they were developed by the engineers.<ref name="livingandworking">Benson, Charles Dunlap and William David Compton. ''[https://history.nasa.gov/SP-4208/contents.htm Living and Working in Space: A History of Skylab]''. NASA publication SP-4208.</ref>{{rp|253–255, 259}} Ground controllers purged the atmosphere with pure nitrogen four times, before refilling it with the nitrogen/oxygen atmosphere for the crew.<ref>''Skylab: A Chronology'', May 14</ref> The secret [[National Reconnaissance Office]] used a [[KH-8 Gambit 3]] to photograph the damaged station.<ref name="day20130520">{{Cite web |last=Day |first=Dwayne |date=2013-05-20 |title=Those magnificent spooks and their spying machine: The spies help rescue Skylab |url=https://www.thespacereview.com/article/2299/1 |access-date=2020-07-10 |website=The Space Review}}</ref>

On May 25, Skylab 2 lifted from LC-39B, the first Saturn IB launch in almost five years and only the second-ever launch from Pad 39B. Booster performance was nominal except for one momentary glitch that could have threatened the mission -– when the Commit signal was sent to the Saturn at ignition, the instrument unit sent a command to switch the launch vehicle from internal to external power. This would have shut down the Saturn's electrical system, but not the propulsion system, and likely cause the disaster scenario of an uncontrollable booster, requiring the Launch Escape System to be activated and the Command Module pulled away to safety, followed by Range Safety destroying the errant launch vehicle. However, the duration of the cutoff signal was less than one second, too short a time for the electrical relay in the booster to be activated, thus nothing happened and the launch proceeded as planned. This glitch was traced to a modification of the pad electrical equipment and corrective steps were subsequently taken to prevent it from happening again.<ref name="livingandworking"/>{{rp|269}}<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730025087.pdf</ref> On reaching the station, Conrad flew their [[Apollo Command/Service Module]] (CSM) around it to inspect the damage, then soft-docked with it to avoid the necessity of [[orbital station-keeping|station keeping]] while the crew ate, and flight controllers planned the first repair attempt. Then they undocked so that Conrad could position the Apollo by the jammed solar panel, so that Weitz could perform a stand-up [[Extra-vehicular activity|EVA]], trying to free the array by tugging at it with a 10-foot hooked pole, while Kerwin held onto his legs. This failed, and consumed a significant amount of the Skylab's nitrogen maneuvering fuel to keep it steady in the process.

Two weeks later, Conrad and Kerwin performed a second EVA, finally freeing the stuck solar panel and increasing the electrical power to the workshop. They had prepared for this repair by [[Neutral buoyancy simulation as a training aid|practicing]] in the [[Neutral Buoyancy Simulator]] at the [[Marshall Space Flight Center]]. Without power from the panel, the second and third Skylab missions would have been unable to perform their main experiments, and the station's critical battery system would have been seriously degraded.<ref name="livingandworking"/>{{rp|271–276}} During this EVA, the sudden deployment of the solar panel structure caused both astronauts to be flung from the station's hull, testing their nerves as well as the strength of their safety tethers. After recovering their composure, both astronauts returned to their positions on the station and completed the EVA.<ref>David J. Shayler, [[British Interplanetary Society|FBIS]], ''Walking in Space'', 2004, p. 213, Praxis Publishing Ltd.</ref>