The United States' existing long-range bomber fleet of B-52s, B-1s, and B-2s are at a critical point in their operational life span. With the average age of each airframe being 50, 28, and 20 years old, respectively, military analysts are beginning to question just how long these aircraft can physically last and continue to be credible weapon systems. As potential adversaries acquire 21st century defense systems designed to prevent U.S. access to the global commons (sea, air, space, and cyberspace) and to limit U.S. forces' freedom of action within an operational area, the ability of these Cold War era bombers to get close enough to targets to be effective will continue to deteriorate. Although the Air Force is committed to the development and acquisition of its proposed Long-Range Strike-Bomber (LRS-B), it is anticipated that flight-testing of the new bomber will not start until the mid-2020s, with initial operational capability near 2030. With this timeline in mind, the Air Force has extended the operational lives of the B-52 and B-1 out to 2040 and the B-2 out to 2058. Air Force and aerospace industry experts insist that with sufficient funding for sustainment and modernization over their expected lifespans, all three of the existing bombers can physically last and continue to remain credible weapon systems. However, appropriations decisions made by Congress based on required military capabilities to meet national security objectives will ultimately determine how long the B-52, B-1, and B-2 will remain in service.