Cold jet test with duct
The launch of space vehicles generates extreme conditions, such as vibrations and acoustics that can affect the launch pad, space vehicles, and their payloads. These acoustic loads are the results of intense acoustic environment generated by the interaction of the rocket-engine exhaust stream mixing with the ambient atmosphere. The primary source of structural vibrations and internal loads during launch is due to these acoustic loads. Therefore, being able to manage and suppress these undesirable conditions is critical to proper functioning of vehicle components, payloads, and launch support structures. The goal of the Launch System Testbed at NASA-Kennedy Space Center is to develop new methods to improve the performance of launch systems by reducing noise, vibration, and stress loads generated during launch.

[new item icon] Air Force Research Lab Study
The LST is performing a study under the sponsorship of the AFRL, Wright Patterson Air Force Base, to develop improved means of reducing the acoustic loads generated during launch. Testbed personnel will develop prototype sound suppression devices and perform scaled tests to determine the efficacy of use on future launch structures.

[new item icon] Vibroacoustic Prediction Methods
Acoustic load environments generated by a launch vehicle represent a principal source of structural vibration. These loads can be a deterrent to the proper functioning of vehicle components, ground support structures, and equipment in the immediate vicinity of the launch pad. A knowledge of acoustic loads, including the overall sound pressure level (OASPL), 1/3 Octave band sound pressure level (OBSPL) spectrum, and the distribution (or correlation) of surface acoustic loads, is necessary to provide the input for vibroacoustic analysis and evaluation of the potential impact on structural and operational integrity. In the design of launch pads and vehicles, it is highly desirable that data on acoustic loads (near-field and far-field noise levels) be generated both analytically and from testing of small-scale and full-scale models. Since full-scale acoustic and vibration testing is often cost prohibitive, the option of small scale testing combined with analytical methods remains as a practical alternative.


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NASA Official: James Heald (James.Heald-1@ksc.nasa.gov) , Director, Spaceport Engineering and Technology Directorate
Curator: Bruce Vu (Bruce.T.Vu@nasa.gov)
Last Revised: October 6, 2004


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