gravity

Six-Hour NASA Spacewalk Begins

Two NASA astronauts began a six-hour spacewalk on Saturday to fix a leak in the International Space Station’s cooling system. Astronauts Rick Mastracchio and Mike Hopkins so far have progressed through the job an hour and a half ahead of schedule—and have been spared the helmet-flooding problem that almost killed an Italian astronaut in July (contamination had clogged up the system which removed moisture from his U.S.-made suit). NASA outfitted the two men with snorkels while they worked to unhook a coolant pump module with a faulty valve. Plans are in place for three spacewalks through Christmas Day to repair the valve malfunction that cut the station’s cooling capability in half last week.