Live in orbit: Successful spacewalk complete

The fourth of five spacewalks planned for shuttle Endeavour's 16-day mission is in the books.

Mission specialists Chris Cassidy and Tom Marshburn, both making their second-ever spacewalks, logged seven hours and 12 minutes outside the International Space Station.

The spacewalk ended at 5:06 p.m. EDT when they plugged their suits into station power.

"The boss says that you've earned a day off tomorrow," radioed station flight engineer Tim Kopra, who guided the duo from inside throughout the day, apparently referring to Endeavour commander Mark Polansky.

Cassidy and Marshburn have locked the Quest airlock's hatch and are beginning to repressurize the chamber.

The spacewalk didn't set any records, as seemed possible earlier in the day.

When their work was running behind schedule, it appeared for a while that the pair might need to return to the airlock for more oxygen to complete the job.

That could have added another hour to their total and made it one of the longest spacewalks on record. But they caught up and that step wasn't necessary.

The spacewalk actually took less than the seven hours, 30 minutes allotted.

Cassidy and Marshburn completed all the day's key tasks, removing and replacing the final four of the six oldest solar array batteries.

That was one of the top mission goals for Endeavour, along with the installation of a new "porch" on Japan's Kibo science lab, and the transfer to it of some science experiments and communications equipment.