Severe random vibration mechanical environment and acoustic excitation are experienced by spacecraft during launch and the vibration or acoustic test is usually to be executed in order to verify the structures. According to the relative test standards, acoustic test is recommended to be done for large spacecraft instead of random vibration, while the random vibration test instead of acoustic test is recommended for small spacecraft. Since random vibration test has seldom been done for large spacecraft, the difference between the random vibration test and acoustic test has little been studied. In order to obtain suitable test specifications for spacecraft vibration test and acoustic test, a complex assembly composed of spacecraft, fairing, satellite adapter, and instrument compartment of the upper stage for L/V is assembled specially on ground, and an acoustic test in the reverberant field for this complex assembly is accomplished. As a result, the vibration specification is extracted from the acceleration PSD with the interface of S/C and L/V, and the sound pressure level inside the fairing is utilized to specify the controlling SPL with the acoustic test. In the end, the results by the complex assembly acoustic test, the spacecraft acoustic test and the spacecraft random vibration test are compared and studied. It is shown by the comparison that the transmitting passes and frequency distribution of acoustic load differ a lot from that of the vibration excitation. The effectiveness of spacecraft acoustic test and random vibration test is assessed based on the benchmark of assembly acoustic test results. The acoustic load usually takes effect in higher frequency band and influences the outer surface of the structure, while the base random vibration is commonly more important at lower frequencies, especially for structures or components near interface of S/C and L/V.
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