When the Roci received the message from Gunnery Sergeant Draper's space suit the header for the encryption code was "TK4.21", an Easter Egg for a stormtrooper in Star Wars: Episode IV - A New Hope (1977). "TK 421, why aren't you at your post?". The code also ended with 1138, a popular Easter Egg to George Lucas's film THX 1138 (1971).
Episode title is "IFF". In military usage IFF means "Identification Friend or Foe", an automated system of radio frequency challenges and responses that allows weapon systems to know who to shoot.
Spot the prop. Mei's pod is a Thule 625 Force Cargo Box with a window added. In 2018 this model was rated one of the top 10 car roof cargo carriers.
Shawn Doyle and Elizabeth Mitchell have previously appeared together in the movie Frequency. Doyle plays a corrupt cop who is murdering nurses. Mitchell plays a nurse and is almost one of his victims