Since Star Trek: The Next Generation was set a century after the original Star Trek series, not only the Enterprise but its shuttlecraft had to upgraded as well. The job of designing a twenty-fourth-century shuttle was Andrew Probert’s, who also designed the second series’ flagship.
In an effort to make the new shuttle more visually interesting, Probert originally planned to move the entrance to the front of the vessel.
He explained in an interview with Star Trek: The Magazine (January 2001), “There’s a ramp that lowers between the two operators. The top portion of that would actually slide up, much like a sunroof does on a car, allowing the people to walk straight up into the shuttle between the operators.”
The producers liked the idea, but it proved too ambitious. “They built a shuttle that basically had square edges on it,” said Probert. “Then they came up with the idea of getting into the shuttle from the side.”
The model, which first appeared in the first season episode “Coming of Age,” was even boxier, although it was somewhat reminiscent of the new Enterprise‘s curved lines.
A final modification was made with regard to the windows. Whereas the original model had them running across the length of the shuttlecraft, which might have interfered with the side entry, this configuration was never shown on screen except on displays. Andrew Probert did include the long windows in an artwork he made for a model kit of the pod.
Bernd Schneider details the appearances of Probert’s original shuttlecraft, which came to be known as “Type 7,” as well the different incarnations of its cockpit, at Ex Astris Scientia.
After Probert left The Next Generation, Rick Sternbach was tasked with designing an alternative shuttle for the Season 2 episode “Time Squared.” He recalled in an interview with Star Trek: The Magazine (June 2002):
Everybody was kind of scratching their heads and thinking that maybe we’d have to write the shuttlepod out. I cautiously went up to the front of the room with this very rough but fairly clear sketch. I said, “What if we made it fairly simple? Just planar construction, no compound curves. We can make it look Starfleet; that isn’t the issue. If we do something like this we can make the construction simple but also make it interesting.” They all looked at me, looked at the sketch, and said, “Ah, OK.” Then they approved it.
This new shuttle, dubbed “Type 15,” was smaller, which made it easier to construct a life-sized model.
A miniature version was built by Ed Miarecki to appear in the model of the ship’s main shuttlebay that was seen in Season 5’s “Cause and Effect.”
As with the original Type 7, the Type 15 shuttle underwent several changes in both its exterior and interior during the series’ run. Bernd Schneider has the details at Ex Astris Scientia.
By the fifth season, The Next Generation‘s shuttle complement was joined by the larger “Type 6”, which was a redress of the shuttlecraft that had appeared two years earlier in Star Trek V: The Final Frontier.
“We made use of one of the Trek V shuttles by chopping a section out of the middle and giving it new engines and windows,” Sternbach told Forgotten Trek in 2007.
The great thing about it and most of the other Starfleet shuttles we built was the fact that where there are curves, the curves follow a single bend and “softening” the joined edges is no big deal. It was much easier to do the real set pieces that way, even if we did migrate to some ships that had no exteriors except for CGI.
A new miniature was built under the supervision of Greg Jein and first appeared in the episode “Parallels.” Unfortunately, stock shots from the Type 7 were repeatedly used and paired with Type 6 interiors, an inconsistency that continued into Star Trek: Voyager.
Sources for this story include: Jörg Hillebrand and Bernd Schneider, “Variations of the Type-7 Shuttle,” Ex Astris Scientia; Star Trek: The Magazine 1, #21 (January 2001); and Star Trek: The Magazine 3, #2 (June 2002)