A rocket sled is essentially a small railroad car with rockets attached. It was used extensively, by the United States early in the Cold War, to accelerate and test equipment considered too experimental (hazardous) for testing directly in piloted development test aircraft. The equipment to be tested under high acceleration or high airspeed conditions was installed along with appropriate instrumentation, data recording , and telemetry equipment on the sled. The sled was then accelerated according to the experiment's design requirements for data collection along a length of isolated, precisely level and straight, test track.
Testing ejection seat systems and technology prior to their use in experimental or operational aircraft was a common application of the rocket sled at Holloman Air Force Base.
It is interesting to note that Murphy's law originated in conjunction with rocket sled testing.
External Links
http://www.improb.com/airchives/paperair/volume9/v9i5/murphy/murphy1.html
