Quantum Coating has announced that it is about to complete the James Webb Space Telescope (JWST) mirror coating program. The company had received the contract in 2007 and the primary work is to apply gold coating on all the mirrors of the JWST.
Till now, Quantum Coating has coated over two thirds of the reflective optics. The telescope has a range of reflective optics, including primary, secondary, tertiary and fine steering mirrors. The primary mirror is made of light-weight beryllium material and consists of 18 hexagons, each measuring 1.3 m diagonally.
The coating project presented a number of technical challenges to Quantum Coating. The company’s team handled huge, fragile and irreplaceable beryllium substrates. It was able to manage stress, durability and film reflectance with the capability to withstand obsolete zero cyogenic cycling. The team attained uniform thickness on 1.3 m curved surfaces.
Ian Stevenson, Quantum Coating’s Director of Coating, pointed out that the company has been concentrating on plant acquisition and upgrading facilities in the initial two years of the project. A customized 96” coating chamber has been developed and installed. In addition, the company has made investment in metrology for thickness, micro roughness, stress and reflectance. Additional investment has been made in thermal cycling station.