The U.S. Defence Advanced Research Projects Agency (DARPA) launched an exploratory development program with the goal of placing a high-altitude, long-endurance UAV anywhere on the planet within one hour. Delivered by intercontinental ballistic missile, the air vehicle will then be required to remain on station until relieved or until its mission is completed. Known as Rapid Eye, the DARPA initiative could ultimately emerge as the ISR portion of a larger U.S. requirement for a Prompt Global Strike (PGS) force able to function independently of overseas bases or nearby naval forces. The U.S. Air Force has proposed a stealthy, subsonic manned bomber that would enter service after 2018, but it and the U.S. Navy are also exploring the potential of equipping both land- and sea-based ICBMs with conventional warheads. The Navys program is based on the Trident submarine-launched ballistic missile, while the Air Force is developing the Common Aero Vehicle (CAV) a hypersonic glider that could carry conventional munitions atop modified Minuteman or Peacekeeper missiles. CAV has also been proposed as a UAV carrier. A parallel effort, called Conventional Strike Missile, omits the glider and swaps the ICBMs nuclear warheads for sensor-fused submunitions or other precision-guided weapons. Some fear, however, that blurring the distinction between conventional and nuclear weapons is inherently dangerous and could increase the likelihood of a nuclear confrontation. China and Russia, for example, might mistake the launch of a conventional or UAV-carrying ICBM for a nuclear attack and respond accordingly.
U.S. engineers have long wanted to fold up an airplane inside a rocket and send it on a mission to cruise through the atmosphere of Mars. They now have a new potential customer for the concept: the Pentagon's Defence Advanced Research Projects Agency. DARPA started a program earlier this year called Rapid Eye to demonstrate technology that would lead to development of a rocket-delivered unmanned plane to fly high over the site of a natural disaster or other "hot spot."