Two unmanned aerial reconnaissance programs operated by the CIA during the Cold War may have anticipated the rise of military drones by a half-century, according to newly declassified government documents.

The two programs, known as AQUILINE and AXILLA, took shape during the early 1960s when mounting losses of U-2 spy planes convinced agency officials of the need for small, undetectable aircraft capable of conducting limited flyovers and bombing sorties.

The government files, which were released under the Freedom of Information Act to George Washington University's National Security Archive, offered the first official acknowledgement of Area 51. But it's what was happening there that is arguably more interesting.

AQUILINE was developed first. In 1965, two engineers from the Office of Research and Development issued a request for proposals for a small, unmanned drone. Douglas Aircraft was the only company to respond.

"The AQUILINE prototype developed by Douglas Aircraft . . . was essentially a powered glider with an 8.5-foot wingspan," the documents read. "The aircraft weighed only 105 pounds. AQUILINE's tail-mounted engine drove a two-bladed propeller."

A 3.5-horsepower engine originally meant for chainsaws was responsible for driving the propeller.

Even as AQUILINE was moving forward, the CIA was developing another drone prototype. The AXILLARY project looked much more like a conventional aircraft:

AXILLARY wound up being too large and loud for covert missions, the CIA determined, but considered using it as a peacetime device or as a way to deliver warheads over short ranges.

To turn the drone into a self-guided missile, the CIA installed an autopilot system for $50,000 and added radar-homing equipment. AXILLARY would likely have been deployed to North Vietnam — presumably to disable surface-to-air missile sites, according to the documents.

"The radar homing system proved successful as AXILLARY sought out and destroyed a radar during testing at China Lake Naval Air Station," the documents read. "However, the end of US involvement in Vietnam in early 1973 led to the cancellation of DoD funding."

AQUILINE was ultimately also canceled in 1971. Despite being near invisible to chase aircraft in flight tests, the cost of the project was turning out to be a major boondoggle — especially because the drone could only be recovered by crashing it into a net near the ground.

"One or more of the aircraft was always being repaired, and eventually three of the five AQUILINE prototypes were destroyed in testing," said the documents.

At least one of these prototypes was flown from Area 51 more than 20 times, according to Chris Pocock, a historian and author of several books about the CIA's U-2 program.

The United States still spends vast amounts on drone programs. The Predator project alone cost $2 billion, and the Reaper program nearly $12 billion. But unlike their predecessors nearly 50 years ago, today's machines are vastly more lethal, undetectable and sustainable.