Describe the concept behind Next Generation, which was of a different time.

When models are created for the show, they vary in size depending on the amount of use and what level of detail is required. For example, the model for Deep Space 9 was six feet in diameter, and we had to make a special model without one centre that had the outer rim, so we would use it for shots where we�re see out from the centre hub. And that was an incredibly expensive model because it required special steel armatures and several different circuits of lighting. So a model like that could be in excess of hundreds of thousands of dollars and take many months to build. On the other hand, certain models are free, such as ones that I would make with little broken parts and stuff, if it�s for one-time use only, for a little ship that flies by.

Voyager was five feet long, the physical model. The Enterprise for Next Generation, we first had one that was built by Industrial Light and Magic, that was six feet long, but we found that it was too unwieldy because of its size when we were shooting passes, which is when you�re shooting the silhouette of the ship that you can then use to make a hole in the background where the ship goes. So we subsequently had Greg Gene make the four foot Enterprise, which is what we used primarily on TNG.