NASA probing slow air leak in space station

CAPE CANAVERAL, Fla. -- The international space station is experiencing a slow, steady drop in air pressure, and American and Russian flight controllers are investigating possible causes.

Mission Control notified astronaut Michael Foale and cosmonaut Alexander Kaleri about the leak just before their bedtime late Monday afternoon.

"There's no action for you at this time and no immediate concerns," Mission Control assured the two men. "We'll continue to investigate this on the next shift and we may have some actions for you tomorrow."

Not long afterward, Foale radioed back that the men had gone ahead and done some checks of their own. He reminded Mission Control that Kaleri, one of the last two men on Mir, was sent to the Russian outpost in 2000 to look for a similar leak and was doing a thorough check of all the accessible valves leading to the vacuum of space.

The valves on the U.S. and Russian sides of the space station checked out fine, Foale said.