MODEL RELEASED. Greenscreen technology with an actor as an astronaut. This technique is also known as 'bluescreen' and 'chroma key'. It is widely used in television and filmmaking as a background. The actor, in this case an astronaut, is filmed with the greenscreen background. The true background footage is filmed seperately and the greenscreen background is then replaced with the true background scene, often using computer generated imagery (CGI). The astronaut will be mapped out onto a space background.