 Promoted to Lieutenant Colonel on March 1, 1990, he took command of the 2d Space Operations Squadron at Falcon AFB in Colorado in August of the same year.After his first command tour, Shelton served as executive officer to the Vice Commander, Air Force Space Command for a year beginning in June 1992.He moved on to assume command of the 50th Operations Group at Falcon AFB from June 1993 to July 1994.