The 1st Space Wing replaced the 46th Aerospace Defense Wing on 1 April 1983. Thereafter the 1st Space Wing transferred host unit responsibility to the 3d Space Support Wing activated on 15 October 1986. Army and other units transferred from the former Ent AFB Federal Building to Peterson Building 2 (renamed the Eberhart-Findley Building in October 2012). On 15 May 1992, the personnel and equipment of both the 1st SW and 3d SSW merged to become the 21st Space Wing. Peterson's Space Analysis Center was at the corner of Academy & Fountain Blvds by 2004 before moving on base to bldg 1470, and in 2004 the Space Operations School used a building along I-25 at Woodmen Drive.