CAPE CANAVERAL, Fla. (AP) _ The countdown has begun for another space shuttle trip to the Russian space station Mir.

NASA began the countdown Monday for the space shuttle Endeavour, which is scheduled to blast off Thursday night with astronaut Andrew Thomas.

Thomas, an Australian-born engineer, will replace David Wolf, who has been on Mir since September. Thomas will be the seventh and final U.S. astronaut to live on Mir.

``How do you like my space station haircut? You think it's going to last four months? Probably not,'' Thomas told reporters, patting his closely cropped blond hair.

Thomas expects his 4 1/2-month Mir stay to be uncomfortable at times given the deteriorating state of the thermal system and other station equipment. ``But I don't feel that the safety is an issue for me flying on this vehicle,'' he said.

Endeavour will carry up a new air conditioner and computer for the 12-year-old space station, as well as food, water and other supplies.