The U.S. Air Force has awarded Sierra Nevada Corporation $13 billion to develop a new "Doomsday" plane to replace the E-4B aircraft. This was reported by Breaking Defense, noting that these aircraft serve as mobile nuclear command and control centers. The new contract will be effective until July 2036 and will enhance the program's defense against nuclear cyberattacks, replacing the Air Force's aging fleet of four E-4B planes. Such aircraft are used as command and control points in nuclear warfare.