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CBS News Space Place - Space News CBS News Space Place CBS NEWS Coverage of Breaking Space News Posted: 10:40 AM, 8/11/10 By William Harwood CBS News Space Consultant Editor's Note... The CBS News space pages have been upgraded to improve compliance across different platforms. The revamped space pages are located here: http://www.cbsnews.com/network/news/space/home/index.html. Please bookmark the new site. CBS News space emails will continue as usual, but this page is being discontinued. Changes and additions: 08/07/10 (07:25 AM): U.S. EVA-15 begins (ammonia pump R&R) 08/07/10 (06:35 PM): Marathon spacewalk derailed by ammonia leak, jammed fitting 08/09/10 (04:15 PM): Flight controllers revise plans for second coolant repair spacewalk 08/10/10 (05:45 PM): NASA managers approve plan for Wednesday spacewalk (UPDATED) 08/11/10 (06:15 AM): Spacewalk preparations slightly behind schedule 08/11/10 (08:30 AM): U.S. EVA-16 begins (ammonia pump R&R part 2) 08/11/10 (10:40 AM): M3 ammonia line successfully disconnected 10:45 AM, 8/11/10, Update: M3 ammonia line successfully disconnected Astronaut Douglas Wheelock, applying brute force to shake a balky connector loose, successfully demated a final ammonia line from a failed coolant pump module today, setting the stage for the pump's removal and eventual replacement. Because of a significant ammonia leak in the M3 connector during a spacewalk Saturday, Wheelock and Tracy Caldwell Dyson were unable to complete preparations for the pump's removal, leaving the line in place pending additional troubleshooting. Today, the astronauts planned to first close a quick-disconnect fitting on the outboard end of the S1 truss to isolate the line leading to the M3 connector. But Caldwell Dyson was unable to depress a release button, preventing her from closing the outboard quick- disconnect. Flight controllers then told Wheelock, anchored to the end of the space station's robot arm, to press ahead with an attempt to simply close the leaking M3 connector in hopes that lower pressure in the line, the result of earlier ground-commanded nitrogen venting, would reduce the leakage enough to disconnect the line from the pump. To the relief of anxious flight controllers, the connector closed easily and no major leakage was observed. "I don't see anything leaking," Wheelock reported. "Excellent," replied Oscar Koehler from mission control in Houston. "And Wheels, if you see any leak, we're comparing this leak to what you saw when you first did the SPD on EVA-1. "OK, I see a couple of little snowflakes," Wheelock reported a moment later. "But I don't see anything leaking around the white band like last time. ... OK, here they start to come out now by the white band, just little snowflakes." CBS News Space Place - Space News.htm[1/12/2017 10:02:23 AM] CBS News Space Place - Space News The leakage quickly diminished and flight controllers told Caldwell Dyson there was no need to continue work to close the outboard quick-disconnect. "That's great news," Wheelock said. "It's awesome," Koehler agreed. A few moments later, with no observable leakage, engineers decided there was no need to install a vent tool to release any residual ammonia that might be trapped in the line. Wheelock was then cleared to remove M3 from the pump module. But in keeping with M3's now-familiar behavior, Wheelock was initially unable to pry the fitting apart using a lever tool. "We believe there may be ice in there that's keeping it from releasing," Koehler advised. "So you've got a go to ... move the QD left to right to try to shake some of that ammonia ice out of there." After working the fitting from side to side with no success, mission control told Wheelock "you've got a go to shake violently, that's the words I was given, in all directions." Television views from Wheelock's helmet camera showed him energetically shaking the fitting from side to side. After multiple attempts, the connector finally released and Wheelock pulled the M3 line away from the pump at 10:23 a.m. There were no obvious signs of problems with the connector and the astronauts were cleared to press ahead with their pump removal work. Five electrical cables will be demated by Caldwell Dyson before the astronauts loosen four bolts to free the pump from the S1 truss. If all goes well, the pump will be mounted on an attachment fitting at the base of the station's robot arm transporter. 8:30 AM, 8/11/10, Update: Spacewalk begins Astronauts Douglas Wheelock and Tracy Caldwell Dyson, floating in the Quest airlock module, switched their spacesuits to internal battery power at 8:27 a.m. to officially kick off a planned six-hour spacewalk. The primary goal of the excursion is to remove a shorted ammonia pump module so a replacement can be installed during a spacewalk Sunday. This is the 149th EVA devoted to space station assembly and maintenance since construction began in 1998, the 13th so far this year, the fifth overall for Wheelock and the second for Caldwell Dyson. Going into today's outing, ISS spacewalk time stood at 929 hours and 38 minutes, or 38.7 days. For identification, Wheelock, call sign EV-1, will be wearing a suit with red stripes around the legs and use helmet cam No. 19. Caldwell Dyson, EV-2, will wear an unmarked suit and use helmet cam No. 20. The astronauts attempted to remove the faulty pump during a spacewalk Saturday, but one of four ammonia line quick-disconnect fittings leaked, presumably because of problems with an internal valve on the outboard side of the fitting. Today, Wheelock will make another attempt to simply close the M3 quick-disconnect fitting. If the leak persists, the astronauts plan to close quick-disconnect valves at the inboard and outboard ends of the starboard one, or S1, truss where the pump module is located to isolate the ammonia line leading to the leaking connector. Flight controllers earlier lowered pressure in the system and after the astronauts install a vent tool to get rid of any residual ammonia trapped in the line, the M3 quick disconnect will be closed and removed. That should clear the way for disconnection of five electrical umbilicals. After loosening four bolts, the failed pump module will be removed and temporarily mounted on a powered attach fitting at the base of the station's robot arm transporter. If all goes well, a spare pump will be installed and reconnected during a third spacewalk Sunday. Here is an updated timeline for today's spacewalk based on the official start time (in EDT and elapsed time; best viewed with fixed- width font): EDT........HH...MM...EVENT 08:27 AM...00...00...Suits to battery power 08:32 AM...00...05...Post depress/airlock egress 08:47 AM...00...20...Setup 09:12 AM...00...45...EV-2: Close S1 outboard QD 09:27 AM...01...00...EV-1: Vent line routing 09:57 AM...01...30...EV-1: S0/S1 inboard jumper QD closed 10:12 AM...01...45...EV-2: M1 ammonia line restrained 10:27 AM...02...00...EV-2: Start venting 10:37 AM...02...10...EV-1: Close M2 ammonia line CBS News Space Place - Space News.htm[1/12/2017 10:02:23 AM] CBS News Space Place - Space News 11:07 AM...02...40...EV-1: Close vent tool 11:12 AM...02...45...EV-2: Vent tool cleanup 11:22 AM...02...55...EV-1: Close and demate M3 ammonia line 11:32 AM...03...05...EV-2: Cover and restrain M3 11:42 AM...03...15...EV-1: Break torque on failed pump module bolts 12:02 PM...03...35...EV-1: Retrieve adjustable grapple bar 12:02 PM...03...35...EV-2: Release failed PM electrical cables 12:32 PM...04...05...EV-2: Release failed PM bolts 12:47 PM...04...20...EV-1: Remove failed PM with AGB 12:57 PM...04...30...EV-2: Remove failed PM 01:32 PM...05...05...EV-1: Move failed PM to POA 01:42 PM...05...15...EV-2: Break torque on new PM; cleanup 02:02 PM...05...35...EV-1: Cleanup/airlock ingress 02:27 PM...06...00...Airlock pre-pressurization 6:15 AM, 8/11/10, Update: Spacewalk preparations slightly behind schedule Astronauts Douglas Wheelock and Tracy Caldwell Dyson are running about a half hour behind schedule in their preparations for a planned six-hour spacewalk to continue space station coolant system repairs. The spacewalk had been scheduled to begin at 7:55 a.m., but could slip to around 8:30 a.m. if the current pace holds up. 05:45 PM, 8/10/10, Update: NASA managers approve plan for Wednesday spacewalk (UPDATED at 6:25 p.m. with decision to delay start of spacewalk by one hour) NASA managers Tuesday approved plans for a second spacewalk Wednesday to deal with an unexpected ammonia leak that blocked removal of a faulty coolant system pump aboard the International Space Station during a spacewalk Saturday. If the plan works, the old pump will be removed and a new pump installed and hooked up during a third spacewalk Sunday. Astronauts Douglas Wheelock and Tracy Caldwell Dyson planned to spend the night in the station's Quest airlock module at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bloodstreams before the planned 6:55 a.m.