"Gubmint" forces let leak a few bits.....
Notice how the article contains the following qualifier: " — parts of it remain classified — " without saying:
Thus the title of this post.
Hypersonic generally means faster than Mach 5 (five times the speed of sound) or more than 5,700 kph / 3,500 mph. An American SR-71 Blackbird spy plane once crossed the USA from Pacific to Atlantic on a flying start, covering the distance in 63 minutes. This means average speeds approaching 2,500mph / 3,900kph.
For comparison, the bullet from a big game hunting rifle (e.g. grizzly bear or moose) reaches about 2,000 mph / 3,200 kph as it leaves the gun.
It isn't publicly known if the USA or another country still has aircraft capable of 4,000 kph, because the functions the SR-71 once performed are now achieved with satellites. I'll assume aircraft that fast are still around under tight wraps and good disguises.
Nevertheless, the lid isn't as tightly screwed onto the UFO jar as before.