Spacewalk No. 2 nears end; lights on in Tranquility

Ammonia coolant is coursing through the the International Space Station's new Tranquility module, allowing station managers to turn on its lights and begin powering up electrical systems.

"You'll be pleased to know the cooling is flowing through Node 3, and our temperatures are dropping and we're continuing with the Node 3 activation," radioed Hal Getzelman, an astronaut communicating with the crew from Mission Control in Houston.

Node 3 is the technical name for the module named Tranquility through a "name the node" contest.

"Outstanding, outstanding, that's great," replied mission specialist Steve Robinson, who is choreographing today's spacewalk. "We're so happy, our feet are off the floor."

"Good news, Hal, thanks," one of the two spacewalkers said.

Spacewalkers Bob Behnken and Nick Patrick hooked up four coolant lines and later opened valves to allow the ammonia to begin flowing to Tranquility from the station's external cooling system, which dissipates heat generated by electronics to radiators.

They are wrapping up the mission's second spacewalk a little early, as a precaution after a small amount of ammonia squirted from a line toward Patrick's spacesuit.

After an inspection, Behnken saw no signs of a white coating or waxy substance suggesting toxic ammonia had stuck to Patrick's spacesuit.

But NASA's spacewalk rules still labeled the suit "contaminated" and triggered procedures to "bake out" any residue in the sun and to spend extra time cleaning up in the Quest airlock.

Despite that issue, the spacewalkers have accomplished all their major tasks for the day.

After attaching the ammonia lines and wrapping them in insulation, they went on to install some handrails and insulation covers on Tranquility and to prepare the cupola, a windowed observation deck, for a planned relocation late today to its permanent home on the module's Earth-facing side.

"Great job to both of you," Robinson said. "You made a really complex task look really easy."

"I'm glad we got through it," replied Behnken. "It would have been nice to do it without an ammonia spray, but we'll get that behind us and then congratulate ourselves on getting Node 3 cooling."