The moon looms in the foreground, with a small Earth in the background.

The moon looms in the foreground, with a small Earth in the background. (Image credit: Getty)

The U.S. government spent millions of taxpayer dollars to research strange, experimental technologies such as invisibility cloaks, antigravity devices, and a proposal to tunnel through the moon.

The documents, which include nearly 1,600 pages of reports, proposals, contracts and meeting notes, reveal some of the stranger priorities of AATIP, a secretive Department of Defense program that ran from 2007 to 2012.

Luis Elizondo, the former director of AATIP, leaked several videos of an unidentified aircraft moving in seemingly impossible ways to the press after he resigned.

The new documents show that AATIP was more than just investigating reported UFO encounters. The entire cache of 51 documents, obtained by Vice, can be read here.

9 things we learned about aliens in 2021.

The Defense Intelligence Reference Documents (DIRDs), which discuss the viability of various advanced technologs, are most intriguing.

impracticalities of implementing advanced technologies are stressed in many reports. In the DIRD report on invisibility cloaking, the authors write that perfect cloaking devices are impossible because they require materials where the speed of light approaches infinite.

Some reports do not shy away from bold proposals for realizing advanced technologies. The authors propose a plan to look for extremely lightweight metals in the center of the moon that may be 100,000 times lighter than steel, but still have the strength of steel.

NASA plans to return humans to the moon for the first time since the Apollo era with the ultimate goal of establishing a sustainable human presence there. Nuclear explosions on the moon would be contrary to the mission.

It's not clear whether these DIRD documents led to long-term investments in advanced technologies. According to Vice, much of AATIP's agenda relied on contract research from a private company. A $10 million contract was awarded to the company run by Robert Bigelow, who was a friend of the late Sen. Harry Reid, Vice reported.

Three weeks after The Sun obtained more than 1,500 pages of documents related to alleged UFO encounters, another dump of documents arrives. There was a report on the biological effects of encounters with aliens. Live Science previously reported that the report listed paralysis, abduction, and unaccounted for pregnancies as reported side effects of alleged UFO encounters.

Vice reporters will be looking into the database of AATIP documents over the coming weeks. You can follow their coverage here.

It was originally published on Live Science.