Marc's note: Today's spacewalk had to be cut short after only an hour and 32 minutes as a water leak in Luca Parmitano's suit was causing a build-up of water in his helmet. Both astronauts returned safely to the confines of the Space Station. The location of the leak within Parmitano's suit is to be determined.
UPDATE: The post spacewalk news briefing revealed that NASA does not know what caused the problem with Luca's suit at this time. They will be reviewing all the data and examining the suit to figure out the issue. Watch the press conference.