"Aggressor" training was reactivated under the 57th Operations Group in 2003 and in 2006 Nellis had the Air Ground Operations School. On 1 May 2007, the UAV reconnaissance elements assigned to the 57th Operations Group transferred to the 432nd Wing. Detachment 1 of the Space Warfare Center was established at Nellis in 1996 after the "Nellis Combined Air Operations Center", the Warfare Center transferred Nellis Air Force Range control to the 98th Range Wing in 2001, and the annual Aviation Nation airshow began at Nellis in 2002. The Nellis Solar Power Plant constructed 23 April–December 2007 on Nellis' west side was visited by president Barack Obama on 27 May 2009. In 2010, the 505th Operations Squadron operated the Combined Air and Space Operations Center-Nellis.