Got to see James Web Space Telescope in the vib test facility at NASA Goddard today. Took a few photos..
These first photos are with the structure mounted on the horizontal table that provides movement parallel to the ground in one axis. To test the other axis, the test article is rotated 90 degrees. Behind it is another test station that can vibrate in the Z (up/down) axis. Sadly, I neglected to get a photo of the other testing apparatus. It's all very large, but the mechanical tolerances are still very exacting.
You can see the spacecraft components inside the “tent”, which is essentially a portable clean room. It will move within the envelope of the tent when the testing occurs. If you look carefully, you can see one of the folded up mirror assemblies.
After vibration testing, there is an acoustic testing chamber used to simulate the low frequency acoustic energy produced by the launch vehicle.
These photos attempt to capture the scale of this. Note the doorway inside the chamber for scale. Those large holes in the wall are “horns” or really large speakers. You can also see a hint of two outside doors, but I couldn't get far enough back to get a good shot of them.