Russell A. Rourke will leave his post as secretary of the Air Force this week and will be replaced by his deputy, Edward C. Aldridge Jr., administration officials said yesterday.

Rourke, 54, who was sworn in as the Air Force's top civilian Dec. 10 after serving as the Pentagon's chief congressional lobbyist since May 1981, is leaving for personal reasons, associates said.

A graduate of Georgetown University Law School, Rourke held several staff jobs in Congress before coming to the Pentagon. Last year he turned down a lucrative offer from private industry because of his enthusiasm for the top Air Force post, friends said.

Aldridge, 47, a former aerospace executive and strategic arms specialist, will take over the Air Force at a time when it is wrestling with how to salvage its satellite schedule now that space shuttle launches have been put on hold. The Air Force also is confronted with budget cuts that threaten its Stealth bomber and advanced-fighter programs and, like the Navy, it is running short of pilots.

Aldridge has been involved in the Air Force's antisatellite program, which is being challenged in Congress.

Although the White House could name someone else to replace Rourke, administration officials said Aldridge is virtually certain of getting the top post permanently.