A new administrator for NASA will be appointed within two weeks, according to James C. Fletcher, who has held the job since 1986 and is eager to leave.

Fletcher, who announced last year he wanted to retire when a new administration took over, said he was told by President Bush's staff that a successor would be designated soon."I've been assured - of course, I was assured it would be February - that in a week or two there would be somebody new," Fletcher said at an impromptu news conference Monday following the launch of the space shuttle Discovery.

He said the failed White House effort to have former Sen. John Tower confirmed as secretary of defense is one reason no new NASA chief has been named. "They got tied up with John Tower and a lot of other appointments," he said.

Fletcher said his wait to leave the National Aeronautics and Space Administration has not been easy. "I'm getting a little anxious about my situation," he said. "I'm a lame duck, so to speak."

Fletcher has twice served as NASA administrator. He first held the job in the 1970s and then took it in the aftermath of the 1986 Challenger disaster.