One of my hobbies is 3D computer modeling, and recently, being a Star Trek fan, I decided to create a highly detailed model of the USS Enterprise from the original 60s Star Trek series.

I wanted to make it very accurate, so I proceeded to do some research, collecting all of the images I could find on the internet and from books I had. In all of this research, I discovered that there are actually several different versions of the "original" Enterprise. So, here are the major variations of the USS Enterprise I was able to discover.

First Pilot Version
The original filming model of the Enterprise was designed by Matt Jefferies and can be seen in the episode The Cage. It was completely smooth (no grid lines or panel lines of any kind) and clean. The gold colored deflector dish was rather large, and the bridge was quite tall and had a large window in the front. The warp engines had solid red unlit nacelle domes with metal spikes protruding from the tips. The ends of the warp engines were flat, etched with a grid-like pattern. The saucer section was devoid of markings except for the lettering of the ship's name and registry number, and two grey arcs on the top on either edge. The model had no detailing at all on the port side; no marks, no windows, nothing. The electrical wiring entered on this side, and it was never shown on film.

Second Pilot Version
When the first pilot was rejected, a second was ordered: Where No Man Has Gone Before. The Enterprise model underwent a few minor changes, including reducing the size of the bridge and removing the large window in front.

Series Version
After the second pilot was accepted, some changes were made to the Enterprise model before filming began on the series. The size of the deflector dish was reduced. The grey arcs on the saucer section were removed, and several other markings, including small signs, a few stripes, and two large grey triangles (usually assumed to be landing gear for the saucer section) were added. More windows were added. The solid red engine domes with the spikes were removed and replaced with semi-transparent domes and a spinning lighting effect. The back ends of the warp engines had the grid-like patterns removed and replaced with small white hemispheres, looking a little like ping-pong balls. Very faint grid lines were added to the top of the saucer section, drawn in with a pencil.
This version can be seen in all episodes after the pilot. The second pilot version still shows up in the series from time to time, however, because of the expense of shooting special effects footage of the ship; old footage of the ship flying-by was reused many times.

Third Season Version
Before the beginning of the third season, the model was weathered very lightly with an airbrush. However, because of the quality of special effects filming at the time, the difference is difficult to notice on the show.

Original NASM Restoration
In 1974, Paramount Pictures donated the Enterprise to the Smithsonian National Air and Space Museum. Quite a bit of restoration was done on the model, after which it looked like the third season version, with a few differences. The red engine domes were missing, and were replaced with solid unlit domes (similar to those from the pilots, only without the spikes). The gold deflector dish was also missing, and was replaced with an under-detailed version that was larger and more bowl-shaped than the filming version.

NASM 25th Anniversary Restoration
In 1991, in preparation for Star Trek's 25th anniversary, the Enterprise was completely overhauled and restored. The red engine domes and gold deflector dish were restored to their filming condition. Grid and panel lines were etched into the surface, and the entire model was heavily weathered.

Deep Space Nine Version
For the Deep Space Nine episode Trials and Tribble-ations, a new model of the Enterprise was created by Greg Jein. This model looked like the series version of the Enterprise, but was more highly detailed, taking advantage of modern FX filming. Grid lines were emphasized more, and panels were picked out in different shades. Also, the port side was fully detailed, unlike the original.