Earlier, twice within three weeks the space station had a close brush with the debris of a busted Soviet satellite. But it's the first time the threat was serious enough to change the orbit.

Currently, there's a lot of junk in space to necessitate NASA to repeatedly to take evasive action to avoid a collision on orbit for space flights.

On Sunday, Lee Archambault,  shuttle Commander used Discovery's steering jets to change the position of the shuttle and space station to avoid the collision with a space junk piece about four-inch long.

"Adjusting the orbit of the space station is a big deal. It requires a lot of planning. It's very resource intensive.... It's a big deal. It's very tiring. But at the same time, we accept it as a necessary part of our business," space station flight director Kwatsi Alibaruho said.

The action reduced space station’s speed around Earth slightly to prevent an encounter with the junk piece.