Spacewalkers Prime New ISS Solar Arrays for Action
Spacewalkers Patrick Forrester (left) and Steven Swanson work to free a massive joint that will allow new starboard solar arrays to rotate and track the Sun during a June 17, 2007 excursion outside the International Space Station.
CREDIT: NASA TV.
This story was updated at 8:59 p.m. EDT
HOUSTON -- Two astronauts primed the International Space Station?s (ISS) newest solar wings for full operations Sunday during an extra spacewalk by NASA?s Atlantis shuttle crew.
Atlantis shuttle astronauts Patrick Forrester and Steven Swanson spent more than six hours outside the ISS on an excursion primarily aimed at unlocking a 10-foot (three-meter) wide rotary joint and freeing the station?s new starboard solar arrays to track the Sun.
?That?s very good news,? Forrester said when the primary tasks were complete. ?It?s what we came here to do.?
Sunday?s spacewalk began at 12:25 p.m. EDT (1625 GMT) from the station?s Quest airlock, marking the fourth extravehicular activity (EVA) for NASA?s STS-117 shuttle crew. The shuttle astronauts delivered the station?s 17.5-ton Starboard 3/Starboard 4 (S3/S4) truss segments and solar arrays to the ISS last week.
?It?s sure pretty to see those arrays out there,? said NASA astronaut James Reilly, who choreographed the spacewalkers? movements from inside Atlantis.
Sunday?s spacewalk and two extra docked days at the ISS were added to the STS-117 mission to allow time for the repair of a torn protective blanket on the orbiter?s left aft engine pod during a previous excursion.
A stubborn micrometeoroid debris shield, which the spacewalkers had difficulty reinstalling after routing computer cable between U.S. and Russian ISS modules, marked the excursion?s only hitch. Forrester and Swanson secured the panel with tethers to keep it in place.
?It?s definitely not going to be flat enough to go down,? Forrester said.
A similar glitch occurred during a Friday spacewalk, when Reilly lashed a similarly recalcitrant shield into place. Forrester added more tethers to that second debris shield as well during Sunday?s spacewalk.
Solar wings set to turn
Forrester and Swanson spent most of their six-hour, 29-minute spacewalk at the end of station?s new S3 truss, where a pair of vital gears for a rotary joint were found to be cross-wired during a previous spacewalk.
Known as Drive Lock Assemblies, the gears drive the S3 truss? Solar Alpha Rotary Joint (SARJ), which is designed to turn the station?s new Starboard 4 (S4) truss and later outboard segments like a Ferris wheel so their solar arrays always face the Sun.
Forrester installed one of the two gears during a June 13 spacewalk, when the wiring mismatch was discovered. He completed installation of its counterpart Sunday, then helped Swanson remove restraints that had locked the SARJ joint in place.
The SARJ joint may make a five-degree test turn later tonight, ISS flight director Holly Ridings said early Sunday. But it is not slated to begin fully tracking the Sun until Monday, after Russian engineers determine that the station?s main computers governing its Russian-built attitude control system are again fully operational after recent glitches, she added.
Forrester and Swanson also installed a new video camera stanchion on the new S3 truss and cleared structures along its face that originally supported the hefty S3/S4 segments inside Atlantis? payload bay. Their removal clears the path for the station?s railcar-like Mobile Transporter to roll across the S3 truss to a workstation at its starboard-most edge.
Other tasks included: removing bolts from station debris shields; opening a U.S. oxygen generating system vent and securing its debris shield; running an Ethernet cable between Russian and U.S. modules; as well as positioning some tools for use on future spacewalks.
Sunday?s spacewalk marked the fourth for Forrester, who now has a total of 25 hours and 30 minutes of EVA time, and the second for Swanson, giving him a tally of 13 hours and 45 minutes, NASA officials said.
Altogether, the STS-117 spacewalking teams of Forrester and Swanson, as well as Reilly and NASA astronaut Danny Olivas, spent about 27 hours and 58 minutes working outside the ISS, they added.
?They did outstanding,? said Keith Johnson, NASA?s lead STS-117 spacewalk officer, of the four-astronaut team. ?It was just fun to watch.?
In addition to adding the new starboard solar arrays and trusses, the STS-117 astronauts also helped furl a nearly seven-year-old solar wing extending from the top of the station?s mast-like Port 6 (P6) truss to prepare the segment for later relocation.
Olivas also repaired the damaged thermal blanket on Atlantis? left Orbital Maneuvering System (OMS) pod using surgical staplers from medical kits aboard the shuttle and the ISS.
Sunday?s excursion marked the 87th spacewalk devoted to the assembly or maintenance of the ISS and the 59th to begin from the orbital laboratory itself.
Despite the busy day in orbit, astronauts aboard Atlantis and the ISS did not forget it was Father?s Day, and took time to wish their families well.
Both Forrester and Swanson wished their fathers and paternal relatives a happy Father's Day before reentering the space station?s Quest airlock.
?Absolutely, a lot of fathers on this flight and we?re all enjoying a great Father?s Day,? added Reilly, whose own children chose the theme to the television show ?Band of Brothers? to awake the Atlantis crew Sunday.
Inside the ISS, Expedition 15 astronaut Clay Anderson called Mission Control to say hello to his daughter Sutton Marie and son Cole, and reminded flight controllers to spend time with their own children after today?s busy day in space.
?Happy Father?s Day to everyone downstairs,? he said.
NASA is broadcasting the space shuttle Atlantis' STS-117 mission live on NASA TV. Click here for mission updates and SPACE.com's video feed.
- SPACE.com Video Interplayer: Space Station Power Up with STS-117
- IMAGES: Atlantis Shuttle?s STS-117 Launch Day
- Complete Shuttle Mission Coverage
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