The Pentagon spent tens of millions of dollars researching the possible existence of unidentified flying objects, or UFO's.
That's according to a report by the New York Times.
The $22 million "Advanced Aviation Threat Identification Program" began in 2007.
It was pushed by former Senate majority leader Harry Reid.
The Nevada Democrat has long had an interest in UFOs.
The New York Times reports much of the money for the project went to an aerospace firm owned by billionaire Robert Bigelow, a longtime friend of Reid.
Bigelow has said he believes UFOs visit earth.
The defense department has never before acknowledged the existence of the program.
Pentagon officials say it shut down in 2012.
But the Times says officials with the program have continued to investigate encounters brought to them by service members, while carrying out their other duties.