Spacewalkers Rick Mastracchio and Clayton Anderson switched their suits to battery power at 2:14 a.m. EDT to start the third spacewalk of the STS-131 mission. They will connect nitrogen and ammonia fluid lines to the new Ammonia Tank Assembly (ATA) while robotic arm operators Stephanie Wilson and James P. Dutton Jr. move the old ATA into space shuttle Discovery’s payload bay for a return ride to Earth. The spacewalk is planned to last six hours, 30 minutes.
Mastracchio is EV-1, wearing red stripes on his spacesuit and Anderson is EV-2, wearing a white spacesuit. Mastracchio’s helmet camera displays number 19 and Anderson’s displays 20.