MOONS update - Fibre Positioning Module connected to Rotating Front End
14 Nov 2023



After almost 1000 Fibre Positioning Units have been secured in place project reaches major milestone.




MOONS (Multi-Object Optical and Near-infrared Spectrograph) is a groundbreaking spectrograph designed for the Very Large Telescope (VLT) in Chile. An international consortium spanning six countries is being led by the UK ATC and this large-scale astronomical instrument is currently being assembled in the Crawford Lab on site in Edinburgh. 

The MOONS Fibre Positioning Module (FPM) was integrated with the instrument Rotating Front End on Monday 6​ November, marking a major milestone for the project.  

The FPM primarily consists of ~950 Fibre Positioning Units (FPUs), the fir​st of which were delivered by MPS Microsystems in June 2019.  Since then the UK ATC has extensively tested and calibrated each FPU on site before building up the full assembly row by row.   

​Adding each individual FPU to the FPM has been an incredibly complex process. Over the four-year construction period, the installation team has overcome many challenges, such as designing custom 3D printed tools to help with connector mating, using veterinary forceps to guide fibres and undertaking lots of very delicate operations in improbably tight environments. 

To connect the FPM to the Rotating Front End the entire plate (weighing approx. 265kg) had to be lifted by crane, moved across the lab and gently lowered into place. 

So much time, concentration and fingertip skin has been sacrificed that seeing the completed FPM hanging on a crane hook was a scary moment for the team. However, the operation was carefully planned and went perfectly, much to everyone's relief!  

Focus now moves onto software testing ahead of provisional acceptance by European Southern Observatory for shipping to the VLT in Chile.  ​