In space, no one can hear you scream, as the old saw goes. Does the same hold true for yelps of frustration at maintenance tasks gone awry? No doubt the crew aboard the International Space Station (ISS) has the answer after its recent spate of glitches and repair woes.

The third and final spacewalk of the Discovery shuttle mission to the ISS hit a snag yesterday, as a cargo carrier refused to swing out. The platform, one of two intended to store spare parts on future missions, was also the center of a snafu in the second spacewalk Saturday, when astronauts apparently installed a pin in the assembly upside down. ISS flight director Kwatsi Alibaruho told Reuters, however, that the pin was not to blame for the stuck platform. "We thought initially that the incorrect installation of the pin was the reason we were not able to rotate the (mechanism) down to its proper configuration," he said. "We now believe that (it is) just much, much stiffer than expected."

The hang-up led mission managers to secure the platform, deferring its deployment for a later date, and to skip an attempt to ready the carrier on the other side of the station's truss.

There was some good news out of the ISS as well—solar upgrades to the station to help double its capacity to six were completed during the mission, and a balky urine-to-water recycling system seems to be working after Discovery delivered a replacement unit. NASA says crew members have collected 15 pounds of water from the system, but samples will be returned to Earth on the shuttle for testing before ISS inhabitants can begin to imbibe.

President Barack Obama spoke to the astronauts on board the station today from the White House, thanking them for their hard work. "I'm told you're cruising at about 17,000 mph so we're glad you are using the hands-free phone," he joked to the crew, according to the Orlando Sentinel.

Photo credit: White House/Pete Souza