This week's featured item is, technically, half of a Star Trek movie -- it is "Part 2 of Two Discs".
This is an RCA VideoDisc version of Star Trek - The Motion Picture. It utilized RCA's Capacitance Electronic Disc system, which looks like sort of a cross between a record and a laser disc (see photos). You would insert the entire plastic cartridge into the player, which would pull the disc and read it using a needle.
These discs were made in the early 1980s. By the time they were being produced, VHS tapes were coming onto the scene, so VideoDisc players were only made for a few years. Discs were made in advance so they would be ready for the new players, and RCA continued producing discs for a few years after they stopped producing players.
RCA listed Star Trek - The Motion Picture as the third most popular VideoDisc of 1981. Original Star Trek episode The Menagerie was #10, the only non-movie to make the top 20.