51.   They are replacing the current crew of three, which has been living on the orbiting outpost since March.

52.   Their replacements, two Americans and one Russian, will live aboard the orbiting outpost until May.

53.   They had feared that small chunks of frozen fuel might damage critical optical sensors on a Soyuz capsule attached to the orbiting outpost.

54.   They will be the fourth crew to inhabit the orbiting outpost.

55.   They will replace the two Americans and one Russian who have been living on the orbiting outpost for six months.

56.   Their replacements, two Americans and one Russian, who will live aboard the orbiting outpost until May.

57.   They feared that small chunks of frozen fuel might damage optical sensors on a Soyuz capsule attached to the orbiting outpost.

58.   They have been living aboard the orbiting outpost since December along with their Russian commander, Yuri Onufrienko.

59.   They will remain on the orbiting outpost until mid-May.

60.   Two space station astronauts went out on a spacewalk Wednesday in a test of an American-made exit used only once before at the orbiting outpost.