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 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. 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.