The Advanced Aviation Threat Identification Program (AATIP) was a secret investigatory effort funded by the United States government to study unidentified flying objects, but it was not classified. It was first made public on December 16, 2017. The program began in 2007, with funding of $22 million over the five years until the available appropriations were ended in 2012. The program began in the U.S. Defense Intelligence Agency. Although the official AATIP program has ended, a related group of interested professionals have extended the effort in a nonprofit organization called, 'To the Stars Academy of Arts & Science.'
Initiated by then U.S. Senator Harry Reid (D-Nevada) to study unexplained aerial phenomena at the urging of Reid's friend, Nevada businessman and governmental contractor Robert Bigelow, and with support from the late Senators Ted Stevens (R-Alaska) and Daniel Inouye (D-Hawaii), the program began in the Defense Intelligence Agency in 2007 and ended after five years, with a budget of $22 million spread out over five years.
Interviewed in the aftermath of the program's disclosure, Reid expressed pride in his accomplishment, and was quoted as saying "I think it's one of the good things I did in my congressional service. I've done something that no one has done before."
The program was headed by Luis Elizondo, who resigned from the Pentagon in October 2017 to protest government secrecy and opposition to the investigation, stating in a resignation letter to US Defense Secretary James Mattis that the program was not being taken seriously.
Politico published a statement by a former staff member that, "After a while[,] the consensus was [that] we really couldn't find anything of substance," ..."They produced reams of paperwork. After all of that there was really nothing there that we could find. It all pretty much dissolved from that reason alone—and the interest level was losing steam. We only did it a couple years."
The program's leader, Luis Elizondo, said on December 19, 2017, that he believed there was "very compelling evidence we may not be alone."
The program came to public attention on December 16, 2017, in news stories in Politico and The New York Times. The story in the Times included doubts about alien visitation expressed by James Oberg, a space writer and UFO debunker, and Sara Seager, a scientific specialist on the atmospheres of extrasolar planets. Oberg said "There are plenty of prosaic events and human perceptual traits that can account for these stories", although he welcomed further research. The Times also reported that "Robert Bigelow, a billionaire entrepreneur and longtime friend of Mr. Reid, received most of the money allocated for the Pentagon program."
Although the program was not named specifically, program leader Elizondo was quoted in The Huffington Post in late October 2017. Several days earlier, Elizondo announced his involvement in founding an aerospace, science, paranormal and entertainment company called, 'To the Stars.'
The Washington Post reported on December 16, 2017 that Elizondo was responsible for the public release of footage taken by United States fighter jets that appears to show aerial objects maneuvering in inexplicable ways in the USS Princeton aerial object incident. The newspaper also stated that it had conducted several interviews with Elizondo and former Deputy Assistant Secretary of Defense for Intelligence Christopher Mellon, who is associated with Elizondo in a private venture named, 'To the Stars Academy for Arts and Sciences.'