(Mindy Weisberger) Between 2014 and 2015, seasoned pilots in the U.S. Navy experienced a number of harrowing encounters with UFOs during training missions in the U.S. While pilots were mid-flight, their aircraft cameras and radar detected seemingly impossible objects flying at hypersonic speeds at altitudes up to 30,00 feet (9,144 meters); these mysterious UFOs did so with no visible means of propulsion, The New York Times reported on May 26.