How did you build the rocks on the planet sets?

Most of those were fibreglass rocks that the studio had. We had faked in a few distant rocks out of Sellotex or something like that. When we built the planet set for the series we made them primarily out of foam.

There were a lot of large rocks at the studio, but usually they were fibreglass on steel frames and very heavy. We found we could take very small pieces along, make pyramids out of them and craft paper, burlap rags and shoot foam on �em, and make a rock or boulder ten by twelve feet and twelve feet high which four men could pick up and walk off with. Whereas with the heavy stuff that the studio had, you had to clear the sand and get five or six men to try to move �em on rollers. So the foam was infinitely better for us.