The MOONS team was saddened to hear of the recent death of David Sun, one of the key mechanical designers on the project. David had worked for many years at Cambridge University as part of the Kavli Institute for Cosmology, contributing to many different astronomical projects for telescopes around the world.
David was involved with the MOONS project almost from its inception and personally led the mechanical design of the six cryogenic cameras in the MOONS cryostat. As has been described in various places on this website, the MOONS cameras are really one of the most novel and challenging parts of the instrument. They combine extremely large lenses and extremely fast optics – all in a cold environment. The combination of these three factors made the manufacturing and particularly the precise alignment of the cameras extremely difficult.
The design principle of MOONS was that all the “hard part” of the camera alignment would be done in Cambridge. This would be done in a smaller test facility (designed by David) where adjustments could be relatively easily made. Then, once the cameras arrived in Edinburgh to be integrated with the rest of the system, not much would have to be done. It was a good theory but was always high on the instrument’s risk register as it was not an easy task. It is a testament to David’s skill and work as an instrument designer that after years of planning, the first of the cameras sent to Edinburgh was in focus by the first afternoon of the very first cool down. It was a quite remarkable moment!
Beyond his engineering work, David always bought an enthusiasm to the project that enlivened group meetings in Edinburgh, Cambridge and many other corners of Europe. He will be missed by his colleagues in the team, but his major contribution to our project will always be appreciated, both now and in the years of science that are yet to come.
David and some of the Cambridge team with the first of the six completed MOONS cameras