LISA Pathfinder system level acoustic tests completed

The LISA Pathfinder system level acoustic tests were performed on 9 and 10 September 2008 at the Large European Acoustic Facility (LEAF) at ESTEC, The Netherlands. The purpose of these tests was to confirm the load levels on the spacecraft units arising from random vibrations. Initial assessment of the test results indicates that the loads were as expected.

The science and propulsion modules arrived at ESTEC in early August. Since then the modules have been in one of the clean rooms being prepared for these acoustic tests, the first in a series of system level tests scheduled for this year. The tests are performed on representative models of the flight modules with dummy masses taking the place of most system units.

A key aspect of these particular acoustic tests was to better characterize the vibration loads that the core of the LISA Pathfinder instrument (the LISA Technology Package core assembly, LCA) will be exposed to by the acoustic environment.

Information obtained during these acoustic tests will be used to prepare for the forthcoming mechanical test of the LCA. The measurements will be used to avoid exposing the delicate instrument to unnecessary mechanical loads.

Although the results of these acoustic tests are still being thoroughly reviewed and analysed a preliminary assessment of the outcome indicates that the random loads were as expected. The spacecraft thus continues smoothly along the path to qualification.

> Another series of acoustic tests will be repeated at a later date with the flight module of the LISA Pathfinder spacecraft. On that occasion the purpose will be to qualify the spacecraft in launch configuration for the launch vehicle acoustic environment.

Source: ESA Science & Technology
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