In 1997, CIA historian Gerald K. Haines — who was actually the National Reconnaissance Office historian — published “A Die-Hard Issue: CIA’s Role in the Study of UFOs, 1947-90” based on a full review of CIA files ordered by DCI R. James Woolsey in 1993. Key admissions from the CIA’s own document: (1) “Over half of all UFO reports from the late 1950s through the 1960s were accounted for by manned reconnaissance flights (namely the U-2) over the United States.” The early U-2s were silver and reflected sunlight at sunrise and sunset, appearing as fiery objects. (2) Air Force Blue Book investigators, knowing the real cause, “tried to explain away such sightings by linking them to natural phenomena such as ice crystals and temperature inversions.” They were careful not to reveal the true cause. (3) “This led the Air Force to make misleading and deceptive statements to the public.” (4) DCI Walter Bedell Smith — also listed as an MJ-12 replacement member — asked how the UFO phenomenon could be used “in connection with US psychological warfare efforts.” (5) CIA Assistant Director Chadwell briefed the DCI in December 1952 that he was convinced “something was going on that must have immediate attention” and that sightings of “unexplained objects at great altitudes and traveling at high speeds in the vicinity of major US defense installations are of such nature that they are not attributable to natural phenomena or known types of aerial vehicles.” (6) “Air Force and CIA officials agreed that outside knowledge of Agency interest in UFOs would make the problem more serious” — so CIA deliberately concealed its role. This concealment “contributed greatly to later charges of a CIA conspiracy and coverup.”