Views of the STS-101 spacewalk: Astronauts suiting up, the Strela crane being lifted from Atlantis, the cargo boom being assembled, riding the robot arm and the Unity module with Earth in background. Photos: NASA TV/Spaceflight Now

Astronauts James Voss and Jeffrey Williams completed a successful six-hour 44-minute spacewalk this morning, mounting a Russian cargo crane on the international space station's hull, locking down a loose U.S. cargo boom installed last year and replacing a faulty antenna.

They also installed eight handrails on the exterior of the U.S. Unity module, moved a cable bundle that was obscuring an optical target and attached a television camera cable that will be used for future shuttle dockings.

Voss, who will spend five months aboard the space station next year as a member of its second full-time crew, thanked the NASA trainers who prepared "Thanks to the whole team," he said. "It was a good job by everyone making this happen. And for me, it was a particularly meaningful experience coming up here and helping to assemble the space station that's going to be my home next year for about five months. So it was really great for me, thanks to everyone."

"And Jeff and Jim, you certainly did an outstanding, professional job up there paying off all the work all those folks put into this," replied astronaut Mario Runco from mission control. "We appreciate it from down here. And Jim, it must be nice to be able to work on your own house there for a while."

"It sure was, Mario."

The excursion began at 9:48 p.m. EDT Sunday (0148 GMT Monday) when the astronauts switched their spacesuits to internal power. It officially ended with the start of airlock repressurization at 4:32 a.m. EDT (0832 GMT). Shuttle astronauts have now spent 304 hours 37 minutes walking in space in 49 excursions. This was the fifth space station assembly spacewalk, pushing the station total to 36 hours and one minute.

"We had a very successful EVA tonight," said chief flight director Jeff Bantle. "Obviously, all the planning and effort that went in from the training folks on the ground to the crew was very successful and we accomplished all the tasks."

Voss and Williams ran more than an hour ahead of schedule at some points but they lost the time back getting a balky handrail installed and repositioning the U.S. cargo boom at the request of Russian flight controllers. The Russians were concerned the boom might block one or more antennas on the Russian Zarya module had it been left where it was.

Spacewalk trainer Scott Bleisath said this sort of spacewalk will become routine in the months ahead as station assembly accelerates.

"This spacewalk was a good example of what future spacewalks are going to look like, where we will need to perform maintenance on the space station," he said. "Throughout the assembly and operational life of the space station, we'll be sending out crews to perform maintenance and the tasks you saw tonight with the U.S. crane and the replacement of the early communications example is a real good example of how those tasks will be done on future spacewalks."

With the spacewalk behind them, the Atlantis astronauts will open hatches between the shuttle and the station around 8:11 p.m. EDT this evening (0011 GMT Tuesday) to kick off long-awaited work to replace ailing batteries aboard the Russian Zarya module. Four of six batteries will be replaced, along with associated electronic gear.

"We'll be ingressing the station around (8 p.m.) tonight and we'll start our battery swapouts around (12:15 a.m.)," Bantle said. "The mission's going very well and any problems we have are extremely minor. The shuttle orbiter is in extremely good shape. The ISS is performing very well for us and we're looking forward to repairing the battery systems over the next couple of days."

You can follow the flight of Atlantis in Spaceflight Now's Mission Status Center. We will provide continuous play-by-play reports throughout the entire 10-day shuttle flight.