Portable microvibration test facility for spacecrafts

摘要

A new microvibration test facility is described. This test facility has been developed in C.A.S.A.Space Division in Madrid (Spain) and is used for microvibration tests of speciments as large as 2x2x4.5m( 6.5x6.5x14.7ft). The facility is portable and can be used in any place with a minimum environmental conditions, needing two weeks of intallation time and only mains and air-pressure supply (6 bar or 87 psi) for the facility to run. One acoustic cabin is used for acoustic noise screening while an air-mounts system filters the groundfloor noise, acting as off-loading system at the same time. Speciments of 1500 kg(3300 lb) weight have been tested with good results, not being 1500 kg the weight of the heaviest speciment that can be tested. We have measured accelerometer background noise (including all the measurement chain) of 10 sup -6 ms sup -2 (10 sup -7 g's) during test inside a standard clean room with large speciments and force sensors background noise during test of 10 sup -5 N. The paper describes in detail the facility, the type of measurements, excitation capabilities, previous measurements to qualify the site where the facility is going to be installed, type of inputs, suspension system features and the instrumentation.