Blast Berms for the Space Shuttle Launch Pad
We are often asked what type of acoustics we specialize in. Our response: “Everything – The field of acoustics is so specialized we cannot afford to focus on one type of building. The only type of structures we have not been part of in some form are a Nuclear Power Plant or a Concert Hall.” Working on the Space Shuttle Launch Pad a few years ago was one of the more unique projects we have had the pleasure to work on.
The three main elements that make up the Space Shuttle Vehicle at the time of the launch are: an orbiter, which carries astronauts and payloads into orbit; an external propellant tank; and two unmanned solid rocket boosters. The boosters burn in unison with the orbiter’s three main engines, providing the primary thrust to get the Shuttle off the ground.
At the Kennedy Space Center there are a number of security layers. The layer closest to the Space Shuttle Vehicle is referred to as the Perimeter Fence. The problem was that the energy generated by the Shuttle engines and booster rockets sends loose materials and vegetation flying into the chain link Perimeter Fence with enough energy to require major repairs to the fence after every launch. To save money and effort NASA wanted to explore the effects of installing a large earthen berm to protect the perimeter fence. NASA’s concern was that the berm could reflect acoustical and blast energy back to the shuttle and affect the shuttle during lift off.
Working with the Cocoa, Florida office of Tilden Lobnitz Cooper, Thorburn Associates spent two weeks of time reviewing four different designs of varying lengths, heights and slopes. Our summary finding was:
“We have reviewed the four different designs using three different methods. By berm scale, by traditional manual ray tracing and by computer simulation. All three methods indicate that the berm will not redirect acoustical and pressure energy back to the Space Shuttle Vehicle at the launch pad at the beginning of the flight or while in the air along the flight path.”
This project was one that let us go behind the scenes, where we typically could not have access, and help develop a solution to a once in a lifetime problem! It was just as exciting as seeing the shuttle taking off from the Old Denver Airport, on the back of a 747, for one of the program’s initial tests back in 1978.
The project has taken a back seat to other Shuttle projects due to the tragic loss of Shuttle Columbia on 1 February 2003. The next Space Shuttle Launch is scheduled for no earlier than March 2005. NASA’s Web site www.nasa.gov has a lot of very good information if you would like to learn more.