It's definitely a high-value word for him. First because it allows his disciples to get the thrill of believing that they're "in on" something that was not intended to be known. Even more important, it forestalls any critical review—any attempt at analysis can be answered with "of course you can't confirm this. THEY have made it impossible to find the information!"
Accordingly, we've had "Von Braun's Secret" which, as we've seen, is utter balderdash. While Hoagland's web site has been lying idle and un-updated all these many months, it's been stuck on promo for his DVD of a Secrets Conference. Next week the Big Man himself will be appearing at an international conference on "The Secret Space Program and Breakaway Civilization."
It's been a while since he pontificated about the Secret Space Program. If I recall right, the gist of it is that there's a space program run by the supra-national SECRET government. Its capabilities are very impressive, including the ability to destroy a comet. However, it has no manufacturing facilities, no personnel and no launch sites. Cute, huh? NO OF COURSE THERE'S NO EVIDENCE!! DON'T YOU UNDERSTAND?? IT'S SECRET!!!!
 Hoagland actually referred to himself in those words, on his FB page last weekend. The man's arrogance is .... STUNNING.