For a number of years now I’ve been peripherally involved in the effort to bring a planetarium to Central Texas. The brain child of Torvald Hessel, the effort to create the Austin Planetarium eventually grew into the Texas Museum of Science and Technology, which recently opened its doors in Cedar Park, TX (northern suburb of Austin) about a mile or so from where I work. A couple of weeks ago I had the privilege to spend some time there and help a little bit with the set up of the new semi-permanent planetarium at the museum. Scheduling and Customs problems meant that I didn’t get to help out as much as I’d hoped, but I did get to help move the assembled geodesic dome frame into place. Unfortunately I didn’t have my camera with me then so I missed getting pictures of the frame, but I did get pictures of the covered dome while the field service team from the supplier was working on installing the eight projectors that make up the resulting image.
The dome consists of a metal geodesic framework to create a spherical structure, and then an internal screen and external cover are applied to the framework. Negative air pressure is used to keep the screen spherical within the framework, while positive pressure keeps the outer cover taught. Internally, the screen approaches the floor in the front, while going above the door in the back, giving a hemispherical view with a slight tilt. The exterior is decorated with a combination of lunar landscape, constellations, and steam punk gears.
Here’s a shot with the air pressure system in the back. You can also see the vents for air conditioning.