One of the great benefits of being in charge of a magazine like Popular Science is that a lot of doors are open to me. The name and prestige of the title make it possible to walk around the razor wire and see prototypes and experiments generally kept hidden from the general public. But until the National Geographic Channel asked me to do that same thing with a camera crew, I had no idea how secret certain things really are.

Top Secret,” part of Secret Access Week on the [National Geographic Channel]( target=), is our effort to get inside the world of black-budget, off-the-books military hardware. Many of you are familiar with Area 51, where top-secret planes are tested. What you may not know is that there’s another facility, Plant 42, that’s even more interesting, and for the show’s premiere, that’s where we went. Plant 42 is the manufacturing facility outside Los Angeles, maintained by the U.S. military as a place where private companies can build prototypes under military contract. It’s where Lockheed Martin has its skunk works, alongside private facilities for Boeing, Northrop Grumman, and others.

Palmdale, the small, eerily clean and orderly town where Plant 42 sits alongside Edwards Air Force Base, is part of a huge corridor of airspace that extends all the way into orbit and is controlled by its own air traffic control system, so that the military can fly as fast and high as its new toys allow. We did everything we could to figure out what those toys were. I drank with the pilots at a local bar, we camped out at the end of a test-flight runway in the middle of the night, and we chartered a small private plane and snuck into the air space for a moment.

And eventually, we negotiated our way inside Plant 42, and there, we saw the future, not least the autonomous X-47B warplane, our cover story from August. But it’s the process of visiting a place like that that truly blew my mind. We underwent background checks, had our vehicles searched, were under tight control at all times, and had to submit our footage for review at the end of each day. We went to enormous lengths to get in, but it turns out the hardest part of filming a show about “Top Secret” places is getting out.

“Top Secret” premieres Tuesday, October 9 at 8pm PT/ET on the National Geographic Channel. Also check out America’s Money Vault, a look inside the Federal Reserve’s massive system for creating, protecting and destroying money, on Thursday, October 11 at 8pm PT/ET, also on the National Geographic Channel.