I'm not so tough on this episode as others because I think the story and setting are special, particularly for NASA fans. The late Ed Lauter is a former celebrated astronaut who encountered an alien "ghost" (or maybe that is just their manifestation, a fog-like entity; if I were to choose the episode's greatest weakness it is the alien itself) during a space walk, now in charge of a space shuttle launch with the mission of delivering a payload while in orbit around the earth. Michelle Generoo (Susanna Thompson) is a Mission Control Communications Commander (she communicates directly with the astronauts in the shuttle, and her fiancé is the shuttle commander) believing a possible saboteur is working against the shuttle launch. An auxiliary valve unit was tampered with and later once the shuttle is launched into space, there's evidence of sabotage effecting the oxygen for the astronauts. During the episode, we see the alien face (reminescent to the mars face so intriguing to many of us back in the 90s) seemingly possessing Lauter's Lt Col Marcus Aurelius Belt. It even leaves his body and purposely tries to interfere with the space shuttle during their payload delivery! Fox and Scully (David Duchovny and Gillian Anderson) are asked by Michelle to come to Houston and investigate.
Fox is established as a big fan of Belt and NASA and his enthusiasm and respect for both is slightly poked fun at by Scully. But their importance is realized when Belt becomes psychologically and physically effected by the alien possession (which, it turns out, is responsible for causing Belt to sabotage his own shuttle launch, payload delivery, and re-entry!). The NASA intrigue and how the two FBI agents get involved with seeing the re- entry successful (pretty intense sequence where the crew on the shuttle must go it alone trying to cool their heating orbiter, as telemetry and ground control had been tampered with) are the episode's greatest asset, I think. Belt's battle between the human side and the alien so controlling is quite tragic as he must sacrifice himself in order for others not to suffer his fate.
Fox is established as a big fan of Belt and NASA and his enthusiasm and respect for both is slightly poked fun at by Scully. But their importance is realized when Belt becomes psychologically and physically effected by the alien possession (which, it turns out, is responsible for causing Belt to sabotage his own shuttle launch, payload delivery, and re-entry!). The NASA intrigue and how the two FBI agents get involved with seeing the re- entry successful (pretty intense sequence where the crew on the shuttle must go it alone trying to cool their heating orbiter, as telemetry and ground control had been tampered with) are the episode's greatest asset, I think. Belt's battle between the human side and the alien so controlling is quite tragic as he must sacrifice himself in order for others not to suffer his fate.