ACI Capabilities
     - Aero-Thermal and Aero-Acoustic Testing

Aerodynamic heating is one of the most important design considerations of spacecraft. ACI personnel developed a heat sensing system using phosphor paint. This system is in use in multiple hypersonic wind tunnels at NASA/ Langley Research Center.

ACI tested and analyzed the heat distribution of the Space Shuttle TPS with simulated cavity damage during re-entry in 30-inch Mach 10 facility. The phosphor image captured by a high-resolution video camera is analyzed by the software automatically. And the software generates a false-color thermal map. ACI personnel are on around-the-clock stand-by whenever the Space Shuttle is in orbit, in case NASA needs to assess the potential damage and emergency in-orbit repair to the TPS prior to re-entry.

Left untreated, acoustic waves can contribute to metal fatigue. An example is a bi-pod which connects the Space Shuttle orbiter to the External Tank (ET). ACI developed a specialized sensor system to analyze and verify the performance of the re-designed ET bi-pod during NASA's Space Shuttle Return-to-Flight initiative.

ACI developed a special sensor system embedded inside the External Tank model to characterize the aero-acoustics of the Space Shuttle in launch configuration.

The acoustic environment aboard Space Shuttles and the International Space Station (ISS) can be hazardous to the astronauts' long term health and mission safety. The confined spaces and abundance of experiment bays and equipment leads to a noisy environment for astronauts. While long- term health is an issue, the ability to hear commands during an emergency situation is also critical for safety reasons; therefore, equipment and payloads must meet strict noise emission standards before they can be launched into space. ACI researchers, based at NASA/Ames Research Center, measure the sound power of space-bound payload bays assessing whether existing equipment will meet these standards. More importantly, ACI researchers developed new fan designs and other ideas for reducing payload noise.

ACI personnel performed acoustic tests of ISS payload cooling system in NASA/Ames Research Center anechoic chamber.

ACI personnel also excel in design and application of acoustic array appli- cations. The acoustic array can pinpoint the physical location of the source, as well as the spectrum and power of the aero-acoustic wave. Multiple acoustic arrays have been designed, implemented and operated by ACI personnel in many applications, such as wind tunnel test and aircraft fly-over noise tests.