NASA might come dangerously close to the shuttle-station

NASA is monitoring a piece of space junk that might come dangerously close to the shuttle-station.

The object will make its closest approach Tuesday — right in the middle of a planned spacewalk.

News of the space junk came soon after Sunday's docking by Atlantis to the International Space Station. Atlantis is making the very last shuttle flight.

Mission management team leader LeRoy Cain says the size of the space junk is unknown. He says the object might stay at a safe distance but experts won't know until Monday. If necessary, Atlantis' thrusters will move the linked craft.

Less than two weeks ago, space station astronauts had to take shelter in their lifeboats because of a piece of junk. It missed by 1,100 feet (335 meters), the closest encounter yet.