Astronauts David Wolf and Piers Sellers completed a seven-hour one-minute spacewalk today, successfully wiring up a new 14.5-ton $390 million solar array truss segment that was attached to the international space station earlier in the day.

The spacewalk, the 44th devoted to space station assembly and maintenance, began at 11:21 a.m. EDT and ended at 6:22 p.m. EDT. Thirty four NASA spacewalkers, one Canadian flier, one Frenchman and seven Russian cosmonauts have now logged 272 hours and 45 minutes building the lab complex dating back to Dec. 7, 1998.

Today's spacewalk ran 31 minutes longer than expected, thanks primarily to presumably minor problems switching the station's Canadarm2 space crane from one command "string" to another. The switch over took longer than expected, forcing Wolf to complete installation of a television camera system on the far end of the truss without the assistance of the robot arm.

Chief flight director Milt Heflin said the arm glitch occurred when the arm's operating command string was powered down, as required, so Wolf and Sellers could complete hooking up S1's electrical connections. An apparent software glitch prevented engineers from immediately powering the arm back up on its redundant string. Heflin said they eventually succeeded. The original string remains powered down but it is presumably healthy.

"We're inside now, cooling down, and we just wanted to thank you for an amazing job of controlling that and making us feel confident all along," Wolf radioed ground controllers from the station's Quest airlock module. "It didn't quite go as planned, but the whole team really came together to pull it off. It was fun working with you."

"Thank you very much, Dave, we appreciate those words," said astronaut Stan Love in mission control. "And of course, it was great working with you guys as well. You guys did awesome on that camera install. You saved us!"

"I think it was a great team effort," Sellers chimed in. "Incredible. Thanks much."

All of the crew's objectives were accomplished. Wolf and Sellers:

• Connected two redundant sets of electrical cables between S1 and the central S0 truss segment mounted atop the U.S. Destiny laboratory module;
  
  
• Connected fiber optic and data cables between the two truss segments;
  
  
• Released launch locks used to latch down a rotating ammonia radiator support frame during Atlantis' ascent;
  
  
• Released launch locks on a small rail car that will be used by future spacewalkers to move along the solar array truss;
  
  
• Coupled the CETA cart to the Canadarm2's mobile base system rail car;
  
  
• Deployed and secured a redundant S-band antenna;
  
  
• Deployed a video camera and supporting equipment on S1 that will be used to improve visibility during future spacewalks

The only other problem of note came near the end of the excursion when Wolf reported his helmet earphones appeared to be losing power.

"OK, if you can hear me I can't hear anybody, I don't think," Wolf radioed.

"I can hear you, Dave," Sellers replied.

"Dave, can you hear me?" shuttle pilot Pamela Melroy called from Atlantis' flight deck.

"Just barely. Both of my earphones are out. If you can hear me well, try to say 'yes' loudly."

"Yes!" Sellers yelled.

"OK, I barely heard Piers say yes," Wolf reported. "I will get no more complex instructions."

"OK," Melroy radioed.

Flight controllers then suggested Wolf might have inadvertently bumped his volume controls. In any case, he later seemed to be able to hear normally.

The astronauts plan to enjoy a bit of off-duty time Friday before pressing ahead with supply transfers, a Russian media event and an interview with CBS Radio, CNN and Fox. The astronauts are scheduled to go to bed around 8:46 p.m. EDT this evening. Wakeup is scheduled for 4:46 a.m.EDT Friday. The second of three spacewalks to complete S1's outfitting is scheduled for Saturday.