20 Things You Didn't Know About Star Trek II: The Wrath Of Khan (1982)
8. The Reliant Was Originally The Same Class Of Ship As The Enterprise
In early versions of the script, the Reliant was the same class of ship as the Enterprise, which would have allowed the production to save money and re-use the expensive model built for Star Trek—The Motion Picture.
However, at some point, it was decided that it was more important for the two ships to be easily distinguishable during the film’s pivotal space battles. Said production designer Joseph Jennings in a 2002 interview:
In a dogfight you had to instantly recognize which ship you were looking at, so they had to look different. At the same time, you had to make them look like they came from the same culture and had the same technology.
The result of this design philosophy was the U.S.S. Reliant, which Jennings designed with Lee Cole and Mike Minor. Instantly recognizable as a Starfleet vessel, there was nonetheless little chance of confusing it with the Enterprise. Despite the design change, however, the first description of the Reliant was never updated in the script, even as late as the May 24, 1982 revised final draft, which still reflects the writers’ original intention:
In f.g. is the U.S.S. RELIANT, an older, somewhat battered starship of the ENTERPRISE class, with a slightly different configuration.