Spacewalkers Set Out on Airlock Installation Job By Todd Halvorson Cape Canaveral Bureau Chief posted: 11:45 pm ET 14 July 2001 CAPE CANAVERAL, Fla. -- Spacewalking astronauts drifted outside shuttle Atlantis and the International Space Station late Saturday, aiming to help mount a $164 million airlock at the 17-story frontier outpost. Outfitted in spacesuits designed to protect them from the vacuum of space, Michael Gernhardt and James Reilly floated out into the cargo bay of Atlantis about 11:20 p.m. EDT (0320 GMT) as the linked shuttle-station complex flew high above the Pacific Ocean west of South America. "Welcome to space," Atlantis pilot Charles Hobaugh told Reilly, a rookie spacewalker. "Thank you, man. This is cool." Running about an hour behind schedule, the astronauts set out to attach the two-room airlock to a berthing port on the U.S. Unity Module, where it will serve as a dual locker room and doorway for future spacewalking construction and maintenance workers. The first order of business: Removing a large "shower cap" and eight metal seal covers from common berthing mechanisms on either end of the airlock, which was cradled for launch in the rear of the shuttle's cargo bay. Measuring about 10 feet (3 meters) in diameter, the round cap provides a thermal cover for the airlock berthing mechanisms, one of which will be connected to an identical device on the starboard side of the Unity module. The act of doffing the cap, which was stiff from the extreme cold temperatures in space, turned out to be a bit of a wrestling match. "I'm 'rassling this shower cap here for you, trying to get it under control," Gernhardt said before handing it off to his partner. "Thank you very much," Reilly replied. The spacewalkers planned to stow the cap and the covers in shuttle cargo bay storage bins before fitting metal fixtures on the outer shell of the airlock. Dubbed "towel bars" because of their shape and appearance, the fixtures will serve as attachment points for four high-pressure nitrogen and oxygen gas tanks to be installed on the airlock during two spacewalks next week. Guideposts also were to be attached to the airlock shell to help the astronauts mount the huge tanks, each of which weigh 1,200 pounds (540 kilograms) and are enclosed within protective metal cases the size and shape of large doghouses. Then the spacewalkers planned to disconnect shuttle electrical cables used to power airlock heaters, starting up a critical "thermal clock." The joined shuttle-station crews at that point will have just 10 hours to connect the airlock to station power cables to avoid the chance that internal water lines might freeze up and burst, damaging critical systems. So with the clock ticking away, station flight engineer Susan Helms planned to snatch the airlock from the shuttle's cargo bay and then slowly maneuver it up toward the Unity berthing port. The painstaking move -- which calls for Helms first to lift the airlock and then carefully guide it around to the starboard side of the Unity Module -- was expected to take three to four hours. The spacewalkers, meanwhile, planned to retreat to the shuttle's airlock and hook their suits up to servicing lines. The idea: To preserve suit battery power and oxygen supplies in case it takes longer than expected to raise the airlock up to the Unity berthing port. With the airlock poised within three feet (one meter) of the port, Gernhardt and Reilly planned to scale up the station and search for debris within the Unity berthing mechanism. A wayward connector and several screws drifted inside the mechanism when Canadian astronaut Chris Hadfield removed a communications antenna from that part of the station during a spacewalk last April. The two spacewalkers then planned to oversee the docking of the airlock to its berthing port before connecting the airtight chamber -- and its internal heaters -- to station power cables. The astronaut's workday started with an appropriate musical wake-up call from ground controllers: The song "Space Cowboys" by the boy band N'Sync. "Looks like a good day for a walk," fellow astronaut Bob Curbeam said from NASA's Mission Control Center in Houston. "We'll try to get those space cowboys out the door and get the airlock on the station," Atlantis mission specialist Janet Kavandi replied. The planned seven-hour excursion, however, got off to a late start. It took the astronauts longer than expected to suit up and prepare for the sortie. Reilly found that his spacesuit boots were a bit tighter than expected and donned one rather than two pairs of thermal socks so that they would fit. "It was kind of like Cinderella with the wrong slipper," said Hobough, who was helping the astronauts suit up. "Tell Cindy we said hi," astronaut Cady Coleman joked from Mission Control. Two more spacewalking sorties are planned during the shuttle's weeklong stay at the station. Two pairs of oxygen and nitrogen tanks needed to replenish air supplies within the airlock are to be mounted to chamber during excursions scheduled for Tuesday and Thursday. Atlantis and its four-man, one-woman crew plan to depart the station next Saturday. After a two-day trip, the shuttle and its astronauts are scheduled to land here at Kennedy Space Center about 1 a.m. EDT (0500 GMT) on July 23.