Spacewalkers Back Inside International Space Station

U.S. astronauts Clay Anderson and Rick Mastracchio are back inside the U.S. Quest airlock at the International Space Station, having completed the second of three spacewalks planned during shuttle Discovery's stay at the outpost.

The excursion outside the station lasted seven hours and 26 minutes, or about an hour longer than scheduled. The astronauts ran into trouble securing a new ammonia coolant tank on the starboard side of the station's central truss.

It was the 142nd spacewalk performed in the assembly and maintenance of the International Space Station. A total of 887 hours and nine minutes of spacewalking work has been done at the station since the first two building blocks of the outpost were linked in low Earth orbit in late 1998.

It was the 235th spacewalk in the history of the U.S. human space flight program. The first was performed by the late Ed White in on June 3, 1965. That outing on the Gemini 4 mission lasted 23 minutes.

Today's spacewalk increased the total time for the STS-131 mission to 13 hours and 53 minutes.

It was the fifth spacewalk for both Anderson and Mastracchio. Mastracchio now has a total of 32 hours and six minutes of spacewalking time. Anderson's tally: 32 hours and four minutes.