CAPE CANAVERAL, Fla. -- Two of the astronauts aboard the orbiting shuttle-station complex are resting up for another spacewalk.
Spacemen Clayton Anderson and Rick Mastracchio will head back outside early Sunday to replace an old ammonia tank at the International Space Station.
They started the big job Friday.
In an interview Saturday, Anderson said one day in between spacewalks provides enough rest.
He said he often played baseball doubleheaders and basketball games on back-to-back days. He also noted: "We're in pretty good shape for old men, and I think we'll be ready to rock 'n' roll." Anderson is 51, and Mastracchio is 50.
Both are members of space shuttle Discovery's visiting crew. They have another week at the space station before departing.