It's cold up there in space, so before the James Webb Space Telescope gets sent up there, NASA scientists are putting it through its paces, locking parts of it in a vacuum and chilling them to -414 F. We've seen what the vacuum looks like, and here we see the telescope's wings coming in for testing. The wings have 900 parts, mostly made from lightweight graphite composite materials, and can unfold from 16.4 feet to 21 feet. The tests will ensure all of those parts work in a controlled setting before the telescope is rocketed away for real.
NASA does grow some really big oompa loompa helpers, WoWzers!
Having done a bit of engineering design on spacecraft mechanical systems myself, I can tell you the biggest issue is not exposure to the low (-350degF) temps in deep space or the vacuum conditions. Instead, it's the thermal distortions produced in the structure when it heats unevenly due to solar radiation on one side and exposure to deep space on the other side. This can produce a temp differential of over 400degF, which creates a huge amount of thermal distortion in the structure. This thermal distortion can prevent mechanical systems from functioning.