The first test “lift and fit” of the fixed optics in MOONS cryostat has been successfully completed last week by the team at UKATC. The activity is being led by our optical engineer Martin Black.
As with everything on this project the pieces of glass are large, and in turn, so are the parts needed to hold them. Fully testing this procedure give us practice at the complex lifting movements and careful installation processes, without risking any of the really expensive parts. The adage of check twice and cut once applies just as well to big science as it does to small DIY jobs!
The black object in the middle of the photo below is a frame that will contain some of the specialist optics inside of MOONS, namely two dichroics (special mirrors that split up the light) and a grating that makes the spectrum. In total this one assembly weighs just under 120kg!
With things of this weight we need to use a crane to lift them into place. The white pipe in the middle of the photo is an extension piece we attach to the crane to help us get around other parts of the instrument. The silver cylinder to the left upper part is a test camera (without the optics). As it can be seen from the photo, nothing is at right angles to anything else inside the instrument, due to the nature of the design, so getting everything in place is a critical step.
During this first test, the assembly sat nicely on its dowel pins and the holes lined up as expected. The next step will be for the team to test the fitting with dummy masses (instead of the expensive pieces!) to make sure everything fits and out plan all the work, and then move on to the real optics.