The truth is out there! Well, sort of. The 'X-Files' gang were partially right: the National Archives recently published declassified "flying saucer" schematics and the details of the project, dubbed "Project 1974" that hailed from the 1950s.

Back then, the US Air Force decided to team up with a long-gone Canadian company to create a flying saucer airship. The project got as far as building a prototype design and went into the initial rounds of product development before the government pulled the plug in the 1960s.

In the memo that's dated from 1956, it reveals that they wanted to have the saucer reach speeds between Mach 3 and Mach 4, have a ceiling of over 100,000 feet and have a maximum range of 1,000 nautical miles.  The ship ideally would be able to spin through the Earth's stratosphere at over 2,600 miles an hour: meaning that you could go from New York to Miami in 24 minutes.

However, the government pulled the plug because it was getting too expensive: back then, the cost of continuing to develop the prototype would be $3, 168,000 (which translates into $26.6 million in today's economy) and because the desired altitude of 100,000 feet failed: it only hit about five or six feet during the test flights. Guess we'll have to wait for our evil alien overlords to arrive on Earth in order to travel around in flying saucers.