also, according to ruppelt, when he was able to interview the radar and control tower personnel at washington national airport, not a single person agreed with the air force explanation. michael wertheimer, a researcher for the government-funded condon report, investigated the case in 1966. he found that the radar witnesses still disputed the air force explanation, but that did not stop the report from agreeing with the temperature inversion/mirage explanation. ruppelt related that on july 27 the control tower at washington national had called the control tower at andrews afb and notified them that their radar had an unknown object just south of the andrews control tower, directly over the andrews afb radio range station. according to ruppelt, when the andrews control tower personnel looked they all saw "a huge fiery-orange sphere" hovering over the range station. when ruppelt interviewed the tower personnel several days later, they insisted that they had been mistaken and had merely seen a bright star. however, when ruppelt checked an astronomical chart he found that there were no bright stars over the station that night, and that he had "heard from a good source that the tower men had been 'persuaded' a bit" by superior officers to claim that their sighting was merely a star.