Published: Aug 02, 2010 1:40 AM EDT
Updated: Aug 01, 2010 10:40 PM EDT

CAPE CANAVERAL, Fla. (AP) - NASA officials are stressing that the crew on the International Space Station is in no danger, and that the orbiting complex is in a stable situation after the cooling system suddenly shut down over the weekend.
      
But astronauts now face the likelihood of urgent spacewalking repairs.
      
After huddling today, NASA managers have given preliminary approval for a pair of spacewalks, the first of which would take place later this week. Two Americans on board were already scheduled to conduct a spacewalk Thursday for routine maintenance, though the repairs would supersede the original chores.

The trouble arose last night, when one of the two ammonia-fed cooling loops shut down, forcing the astronauts to power down equipment. The ammonia lines ensure that the station's electronic gear doesn't overheat. With one of those out of commission, there's no safeguard in case of a second failure.