Direct, Near Field Acoustic Testing

The better, faster cheaper spacecraft production philosophy in use today usually involves two basic changes from previous satellite programs. The first is the trend toward smaller, more cost effective missions. These missions are somewhat reduced in scope and take advantage of the trend toward miniaturization and reduced component size. Several of these ‘small’ spacecraft can generally be produced quickly, at less cost and less risk to total mission objectives than previous multi-mission spacecraft. The second change is toward an increased dependence on analysis and a reduced verification and test program. It is suggested that the recent string of launch vehicle and spacecraft failures may be directly related to this trend toward less vigorous testing. This author supports a more comprehensive system level test program that will identify weaknesses in design (qualification) and fabrication (workmanship) before launch. More effort needs to be spent on developing such a program and on ways to reduce the cost and schedule associated with it. This paper examines the effectiveness of acoustic testing in meeting those test program goals, suggests a generic test flow that takes advantage of combined testing and presents a more cost-effective approach to acoustic testing.