Doctor Who: Kinda, Episode 1 (1982)

Synopsis
The TARDIS lands on the jungle planet Deva Loka, around the same time as an expeditionary vessel from earth. Leaving a temporarily disabled Nyssa (Sarah Sutton) behind, the Doctor (Peter Davison), Adric (Matthew Waterhouse), and Tegan (Janet Fielding) decide to explore the planet -- and, eventually, to solve the disappearance of several earth astronauts. Written by Christopher Bailey, the first episode of the four-part "Kinda" originally aired on February 1, 1982. ~ Hal Erickson, All Movie Guide