WEBVTT FILE 1 00:00:00.434 --> 00:00:05.072 Music 2 00:00:05.072 --> 00:00:08.942 The James Webb Space Telescope's mirrors and instruments, 3 00:00:08.942 --> 00:00:13.180 Music 4 00:00:13.180 --> 00:00:16.984 kept clean inside a four story tall tent, 5 00:00:16.984 --> 00:00:25.125 Music 6 00:00:25.125 --> 00:00:27.494 are moved into the Acoustic Test Chamber at ... 7 00:00:27.494 --> 00:00:30.964 NASA's Goddard Space Flight Center, in Greenbelt MD. 8 00:00:30.964 --> 00:00:36.136 Music 9 00:00:36.136 --> 00:00:37.638 Engineers blast the telescope with acoustic energy, which ... 10 00:00:37.638 --> 00:00:40.307 results in vibrations similar to what it will ... 11 00:00:40.307 --> 00:00:42.042 experince during launch. 12 00:00:42.042 --> 00:00:43.143 Music 13 00:00:43.143 --> 00:00:49.283 The telescope is tested to frequencies as low as 20 Hertz 14 00:00:49.283 --> 00:00:56.390 and as high as 2800 Hertz ... 15 00:00:56.390 --> 00:01:02.029 and sound pressures as high as 142 decibels. 16 00:01:02.029 --> 00:01:05.098 Music 17 00:01:05.098 --> 00:01:07.601 This is louder than the decibel level ... 18 00:01:07.601 --> 00:01:10.971 of a jet engine at takeoff. 19 00:01:10.971 --> 00:01:13.106 Music 20 00:01:13.106 --> 00:01:15.509 Instant hearing damage would occur at this level without ... 21 00:01:15.509 --> 00:01:20.113 hearing protection. Eardrum rupture occurs at 150 decibels. 22 00:01:20.113 --> 00:01:22.115 Engineers use this test to ensure the Ariane 5 rocket's ... 23 00:01:22.115 --> 00:01:24.251 sound will not damage Webb's structure ... 24 00:01:24.251 --> 00:01:26.119 or systems during launch. 25 00:01:26.119 --> 00:01:28.322 Music 26 00:01:28.322 --> 00:01:34.328 Beep ... Beep ... Beep