Due to all the excitement of last weekend, with debris misses, air cooling systems failures and an already scheduled space walk, today’s Extra Vehicular Activity (EVA) was quite a long one. At 8 hours and 3 minutes, the spacewalk was the sixth longest in history and the longest in support of the International Space Station. Coverage was provided by NASA TV and NASA’s twitter feed.
The walk began at 12:19 BST. A foot restraint was put on the robotic arm of the station by Douglas Wheelock (who tweets here, but not while spacewalking) in order to use it for transportation and was joined by Tracy Caldwell Dyson, who put down her own foot restraint to assist. Wheelock first attempted to disconnect three ‘quick disconnect’ lines to shut down the ammonia pump. The first line came out relatively easily. He had trouble with one and further suggestions were sent to him in consultation with ground control. He moved on to the third line and that came out. The consultations on the stuck line eventually ending with him hitting the device with a hammer, which sorted that out. Unfortunately, once out, the coolant line developed a leak and had to be reinserted. A device was then hooked up to maintain proper pressure in the ammonia pump. The astronauts wrapped up and headed back to a decontamination procedure to get rid of any ammonia that may have adhered to their suits. The suits were inspected and baked out to remove traces of the noxious stuff.
Another two spacewalks are planned to finish off replacing the pump module. The BBC’s report on the EVA is here and highlights from the EVA have been posted to NASA’s Youtube Channel and are shown below: