The ELT M1 support structure from prototype into volume manufacturing: An industrial perspective

In April 2018, VDL signed the contract to deliver more than 900 Primary Mirror Support frames for the 39-meter diameter ELT to ESO. Obviously, the M1 structure is a rather complex module. Because of the extreme output specifications (25 nanometer surface form accuracy of 133 slightly different mirror shapes and positions), as well as the required serviceability and reliability over decades of planned operation, the module truly is an engineering masterpiece. This appears to be the first time in large infrastructure-based astronomy history that a supply chain is set up to manage an order of this magnitude of highly complex M1 support structures. VDL together with its development partners TNO and NOVA has taken up this challenge.