Speaking generally, using those two as very clear examples of a broader principle pertaining to all education and how it potentially intersects with ideology.
A great deal of modern study has been done on racism though, and how accurate it really is. The idea that racist attitudes are grounded in reality that gets suppressed is a standard conservative talking point. A quick google scholar search should reveal an avalanche of work dating back well over half a century that disproves this, though, much like with global warming.
No, afaik I did not have any outright crackpot instructors, though I definitely had some with racist attitudes on occasion.
I don't know if they are or are not inviting foreigners. However, I do know that inviting them and allowing them full access to the station would put national security concerns to rest.
I was talking about American antarctic stations, not all American research sites. Though I'm now curious what the reasoning was for the ISS kick.