ISS Delivery: Astronauts Install New Space Station Power Plant
Spacewalkers Danny Olivas (left) and Jim Reilly prime the new S3/S4 solar arrays for later deployment during their June 11, 2007 spacewalk of NASA's STS-117 mission.
Credit: NASA TV.

HOUSTON -- The International Space Station (ISS) has a new orbital look after a joint team of astronauts installed a pair of massive trusses and solar arrays to the starboard side of the high-flying lab Monday.

Despite a late start, STS-117 spacewalkers Jim Reilly II and Danny Olivas installed the 17.5-ton addition to the station during a six-hour, 15-minute excursion to the starboard-most edge of the orbital laboratory.

?That was a full day, and it all went beautifully,? said Reilly, who completed his fourth spacewalk during the activity, after the excursion. 

The extravehicular activity (EVA) began at 4:02 p.m. EDT (2002 GMT), about an hour later than planned,  due to the sheer heft of the 35,678-pound (16,183-kilogram) Starboard 3/Starboard 4 (S3/S4) trusses and arrays which overwhelmed the station?s U.S.-built attitude control gyroscopes. But the spacewalkers worked swiftly and, ultimately, made up for lost time.

?It was, in a word, incredible,? Reilly said, adding that Olivas worked like a natural despite making his first trek as a spacewalker. ?It?s just something that can?t be matched.?

Monday?s extravehicular activity (EVA) marked the first of three planned spacewalks to install and activate the S3/S4 truss segments and arrays hauled to the ISS aboard NASA?s space shuttle Atlantis. Once deployed, the new solar wings will help provide the power supply necessary to support new ISS modules and international laboratories slated to launch over the next eight months.

During Monday?s spacewalk, NASA mission managers added a fourth spacewalk and two extra days to the STS-117 mission.

Atlantis shuttle pilot Lee Archambault and mission specialist Sunita Williams wielded the space station?s robotic arm to install the S3/S4 truss to its berth at the tip of the station?s Starboard 1 segment. Fellow STS-117 astronaut Patrick Forrester choreographed the spacewalkers movements from the Atlantis shuttle?s flight deck.

During a week of joint activities, Atlantis? STS-117 crew and their ISS counterparts will unfurl the new solar arrays to their 240-foot (73-meter) wingspan and stow away in older solar array reaching to starboard over the S3/S4 truss from the station?s mast-like Port 6 (P6) power tower. Atlantis docked at the ISS Sunday afternoon to kick off the first of NASA?s four planned construction missions to the station this year.

Power in hand

The 45-foot (16-meter) long S3/S4 truss segment is the latest addition to the space station?s main truss, which serves as  the orbital laboratory?s metallic backbone and, when complete, will include 11 sections that together would rival a U.S. football field in length.

At the starboard-most tip of the S4 segment are the folded away solar arrays, which Reilly and Olivas moved into position and primed for deployment during their spacewalk. The astronauts also freed a radiator to cool the new power plant, set up struts to reinforce the S3/S4 trusses and removed some 100 bolts to prepare the outboard S4 element to rotate like a paddlewheel later so its solar arrays can track the Sun.

But that didn?t mean the spacewalkers didn?t take some time out to take in the view.

?I never really understood how dark it gets,? Olivas said. ?Every 45 minutes a sunrise and a sunset, absolutely phenomenal.?

Monday?s spacewalk marked the 84th devoted to ISS construction or maintenance and the 56th to begin from the space station itself. By the excursion?s end, Reilly?s career spacewalking tally increased to four EVAs totaling 22 hours, 45 minutes.

Olivas, who is making his first spaceflight along with first spacewalks during the STS-117 mission, now has six hours and 15 minutes of spacewalking time.

?The smiles on those guys faces go from one ear all the way around to the same ear,? said Expedition 15 flight engineer Clayton Anderson after the spacewalk.

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.

  • VIDEO: A Look at STS-117's First Spacewalk
  • SPACE.com Video Interplayer: Space Station Power Up with STS-117
  • STS-117 Power Play: Atlantis Shuttle Crew to Deliver ISS Solar Wings
  • Complete Shuttle Mission Coverage