15 More Things You Didn’t Know About Star Trek III: The Search For Spock (1984)
3. The ‘sploded Enterprise Is Part Reliant
To depict the destruction of the U.S.S. Enterprise required Industrial Light and Magic to build several new miniatures, because no way was Paramount going to allow them to wreck the very expensive hero model built for The Motion Picture.
One miniature was just the superstructure and bridge dome going poof (if you pay attention in the movie, you’ll notice it’s sitting on a flat surface and not the saucer, and the nacelles are missing). A second was a portion of the top of the saucer with the ship’s name and registry number, used to depict the hull being eaten away just prior to the big bang. The final kaboom was superimposed over the hero model to avoid damaging it.
The third model was the wrecked ship which plunged into the atmosphere of the Genesis Planet. That miniature was built by Mike Fulmer and Ira Keeler (both sadly passed away), and its nacelles were made using molds made for the U.S.S. Reliant for The Wrath of Khan. It’s possible the remaining half-saucer was also made from the Reliant molds. Cost-effective to be sure.