NASA alleges they've been testing them for more than fifty years.
NASA alleges they test them now.
NASA and others have been seen, by the whole wide world, to have been USING them, in the environment for which they were intended, for the last 50 years or so.
You'd have to be a half-blind wombat not to have seen this. There's been live broadcasts, there's been film, video, stills, and a raft of accounts of their activities from the astronauts concerned.
Which bit of this did you miss?