Preparations for Acoustic Testing of the Assembled Solar Array and Sunshade
13 September 2007Engineers from Dutch Space are installing the flight model Herschel solar array and sunshade in the Large European Acoustic Facility (LEAF) at ESTEC, Noordwijk.
The LEAF test chamber is aimed to replicate the vibration environment experienced by a satellite inside the fairing on top of the launcher during the first seconds after ignition, with noise levels reaching up to 144 dB. For this purpose the LEAF facility is equipped with giant loudspeakers that excite the air in the facility chamber in the frequency range 30 to 3000 Hz.
For the testing inside the LEAF, the assembled Herschel solar array and sunshade are attached to the white conical shaped vibration adapter, which has mounting points for the solar array and sunshade at the same relative positions as the actual Herschel spacecraft.
The acoustic tests will commence after the assembled solar array and sunshade have passed the Test Readiness Review later this week. The test schedule includes a series of tests at different noise levels, starting with low-level tests. Between successive tests the results are checked against the allowed parameter ranges before progressing to the high-level noise tests.