Live in orbit: ISS Spacewalk Complete

Astronaut Mike Fincke and cosmonaut Yury Lonchakov have returned safely inside an International Space Station airlock and closed the hatch, ending a nearly five-hour spacewalk.

The Expedition 18 duo, assisted by Sandra Magnus from inside the station, completed all their scheduled tasks.

Chief among those were the installation of a European biological materials science experiment outside the Zvezda service module, and photographing the module to assess its condition after nearly nine years in orbit.

Other jobs included trimming a set of six straps positioned near the Pirs docking compartment, to ensure that they don't interfere with incoming Russian vehicles as they dock.

They also rotated a container holding another materials science experiment.

The spacewalk was the second by Fincke and Lonchakov as a team, and the second ever for Lonchakov, totaling 10 hours and 27 minutes.

It was the sixth for Fincke, who now has 26 hours and 12 minutes of spacewalking time, all in Russuian spacesuits.

Overall, it was 120th spacewalk in support of station assembly and maintenance since construction began in 1998, totaling 755 hours and 56 minutes.

The spacewalk was an attempt to get ahead of some work before space shuttle Discovery's expected arrival on Friday - assuming it launches on schedule at 9:20 p.m. Wednesday.

The shuttle is approaching a "cutout" in advance of the March 26 launch of a Soyuz spacecraft.

If technical or weather delays Wednesday's shuttle launch several days, the mission could be shortened and the number of spacewalks reduced (four are planned) to make sure the mission is finished before the Soyuz arrives on station.

"If we have to shorten the mission, then by getting this (spacewalk) out of the way, it would give us more flexibility for accommodating any planned work that we didn't get done by having to shorten the mission," said Robby Ashley, the payload manager for the STS-119 mission.

That work could then be done after Discovery completes its 10-day stay at the station and returns home.

However, the weather forecast for Wednesday is excellent, and mission managers today reported no serious technical issues that threaten the launch.

IMAGE NOTES: Click to enlarge any of the spacewalk images from NASA TV. In the top photo, cosmonaut Yury Lonchakov can be seen at right ducking behind solar arrays on the Russian Zvezda module. Astronaut Mike Fincke is in the upper right of the picture.