Spacewalkers safely back in station after suit problem Astronauts Christopher Cassidy and Luca Parmitano returned to the International Space Station's Quest airlock Tuesday, closed the hatch and repressurized the compartment to bring a planned 6.5-hour spacewalk to an early-but-safe conclusion, after an unusual and potentially dangerous buildup of water in Parmitano's helmet. As soon as the airlock's inner hatch was re-opened at 9:37 a.m. -- about 40 minutes after flight controllers ordered the astronauts to head back in -- Karen Nyberg and cosmonauts Pavel Vinogradov and Fyodor Yurchikhin removed Parmitano's helmet and used towels to sop up the excess water. By that point, Parmitano was having trouble seeing and hearing, but he appeared in good spirits as he dried off and the other crew members began assisting Cassidy. It is not yet clear what went wrong with Parmitano's suit. He initially speculated a leak in his spacesuit's drink bag, but it could be the result of some other problem. Cassidy and Parmitano carried out a spacewalk last Tuesday to begin working through a backlog of station maintenance and assembly tasks. The outing was the sixth for Cassidy and the second for Parmitano, the first Italian to walk in space. The astronauts only accomplished the first two tasks on their spacewalk to-do list. Cassidy completed work at the Z1 truss atop the central Unity module to install a second set of jumper cables that will enable flight controllers to quickly reconfigure electrical loads in the wake of failures that otherwise would require a spacewalk. Parmitano, meanwhile, began work to complete installation of wiring between the U.S. and Russian segments of the station. Shortly thereafter, the water problem developed and both spacewalkers were told to stand by while flight controllers assessed the problem Within a few minutes, they were told to head back to the airlock and with Cassidy's assistance, Parmitano had no major problems getting back inside. None of the remaining items on the crew's spacewalk task list are time critical and flight controllers will assess the crew's timeline to figure out when another attempt can be made to get the work done. The unfinished tasks include additional cable routing, work to move a wireless camera antenna on the station's power truss and replacement of a camera on the external deck of the Japanese Kibo lab module. The astronauts also planned to reposition a balky door in a compartment on the power truss that houses electrical gear and to remove insulation blankets from a failed electrical switching unit that will be repaired later using the station's robot arm.