7/5/2007 - Experiments scheduled by NASA's Dryden Flight Research Center at Edwards Air Force Base in coming weeks will examine the structural response of modern housing construction to both normal and low-amplitude sonic booms.

Called the Housing Structural Response to Sonic Booms Test, the effort is scheduled to occur at Edwards from July 11 to July 20, between 8 a.m. and 3 p.m. on test days.

The experiment consists of NASA F-18 research aircraft flying unique profiles in order to present sonic booms to an Edwards base house instrumented to measure both pressure and vibration. These flight profiles are designed to keep focused sonic booms away from surrounding communities.

Four low boom and two normal intensity boom missions are scheduled, with up to six sonic booms on each mission. Booms may occur six minutes apart. No more than two missions will be flown on one day.

The primary goal of the test is to quantify the difference, if any, between a 2006 test using an older Edwards base house slated for demolition due to age, and a much newer base house that is representative of modern construction methods and materials.

Engineers from NASA's Langley Research Center in Hampton, Va., are providing and operating more than 100 sensors inside and outside the house, including a microphone 250 feet from the house.

NASA Dryden will mount microphones on a 35-foot tower in a field adjacent to the house, with additional microphones on the ground up to 35 feet from the tower. A Boom Amplitude and Direction Sensor, or BADS, and a ground weather station will also be operated by Dryden personnel.

An Air Force Test Pilot School L-23 Blanik sailplane outfitted with NASA Dryden microphone equipment will also fly during the experiments in order to gather airborne sonic boom data.

The sailplane records the sonic booms before the booms enter the more turbulent air that exists a few thousand feet above the ground, as turbulence can greatly influence sonic boom intensity.

Recent advances in sonic boom mitigation, such as the successful demonstration of the propagation of a shaped sonic boom to the ground in the F-5 Shaped Sonic Boom Demonstrator and Quiet Spike projects, have contributed to a renewed interest in supersonic cruise flight over land. Sonic boom reduction technology may make overland supersonic cruise a reality in the future, so NASA, along with industry partners, continues efforts to reduce the impact of sonic booms.

The test is a Supersonics project managed by NASA's Aeronautics Research Mission Directorate.

Source: NASA Dryden Press Release