Lachlan "Mac" Macleay (born June 13, 1931) is a retired colonel in the United States Air Force and a former USAF astronaut. Although he trained for the USAF Manned Orbital Laboratory (MOL), the program was cancelled before any of the MOL crews reached space. Macleay continued flying for the Air Force and served a combat tour as commander of the 23d Tactical Air Support Squadron (TASS) at Nakhon Phanom, Thailand. The 23d TASS, flying the OV-10 Bronco under the callsign Nail, served as forward air controllers directing air strikes against enemy troops.