Triangular, silent........could it be?
One never knows......... I've always suspected that we've had some kind of Doomsday last-resort kind of defensive/offensive capability in the works. Who wouldn't, if they had any access at all to captured/recovered alien technology. I believe Roswell actually happened, more or less as described by witnesses and participants, and that deep top secret research into last-resort weaponry has been going on ever since. If it does exist, why put it on display unnecessarily? It would really be cool to have a fleet of *unusual* aircraft/spacecraft to deploy if the balloon really goes up.
On the other hand, all the fumbling and stumbling going on for decades around world crisis points makes me wonder if we really do have anything better than conventional satellites up there keeping an eye on things.
damm near silent, just a whoosh when gaining altitude.