The National Aeronautics and Space Administration (NASA) uses UAS technology to conduct hurricane, atmospheric, meteorological and climate studies in hazardous or high-altitude environments. This policy guidance is set out in the Secretary of Defense's policy memorandum entitled Guide to the Domestic Use of Unmanned Aircraft Systems in the United States. Throughout these campaigns, new developments continued to contribute to a large increase in the number of unmanned systems being deployed on the battlefield, a trend that continues after the withdrawal of Americans from the Middle East and Central Asia. Frequently Asked Questions (FAQ) on unmanned aircraft systems (UAS) for owners and operators of critical infrastructure.
While manned aircraft primarily support these missions, the operational use of DoD unmanned aircraft (UAS) systems, rather than manned aircraft, may be appropriate for some sets of national missions, when sustained endurance efforts are required; unmanned aircraft provide superior capabilities; or physical infrastructure limitations prohibit the use of manned, rotating, or fixed-wing aircraft.