In 2006, astronaut Tim Peake from the UK was tasked to perform some physics demonstration on the ISS for the National Space Academy. Tim performed the demonstrations in front of a gridded background specifically made for the purpose.
One of Tim’s video appeared during the former US president George H.W. Bush’s visit to NASA’s Mission Control Center. Flat-Earthers discovered the footage and quickly claim that it used a green screen background for CGI purposes. Such allegation was only from their ignorance and the eagerness to accuse others of lying. Tim’s videos are published in the National Science Academy’s web site as is, proving the background in the videos was merely an ordinary background, not a green screen for CGI.