“These secrets are not really found in NASA.”
It is more complicated than that.
There are compartmentalized portions of NASA that know a lot of stuff—not all of it—but pieces of it.
When a UFO buzzes your craft with theirs it is kinda hard to ignore...
When the pilot of the craft is a military officer, he will route the information as specified in the SOP and then keep his mouth shut as specified for certain topics as specified by the SOP.
Civilian personnel on the ISS are sworn to uphold the communications rules; otherwise, they would not get a seat on the mission.
Some people, not many, will honor their promises. Astronauts are "pick of the litter" people, already well known for outstanding qualities.