Background
The James Webb Space Telescope (JWST) is the product of international cooperation between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The goal of the mission is to study the origin and evolution of galaxies, stars, and planetary systems. The JWST is the successor to the Hubble space telescope, but features optimized functions that will enable it to operate at different wavelengths. The launch of the telescope is planned for 2013 and is expected to operate for five years. INO’s involvement in the project consists of fabricating, in collaboration with COM DEV, the mirrors, antireflective coatings, and connection pads on the two plates that form the tunable Fabry-Perot cavity (TFI, tunable filter imager) that will be incorporated into the FGS (fine guidance sensor).
Solution
The heart of the JWST observatory is a large telescope equipped with a 6.5-meter-diameter segmented primary mirror (compared to 2.4 meters for Hubble) that provides a relatively large field of vision. COM DEV is tasked with supplying a fine guidance sensor (FGS) designed to maintain the orientation of the telescope to within one millionth of a degree of accuracy, precise enough to accurately focus in on an object no thicker than a hair at a distance of 3 km. This level of precision is crucial for the scientific measurements the JWST’s instruments will perform. The FGS also includes an imaging camera with a tunable filter capable of providing scientific images in narrow spectral bands. In 2002, COM DEV approached INO for assistance with this project. INO will fabricate the mirrors, antireflective coatings, and connection pads on the two plates forming the tunable Fabry-Perot cavity (TFI) that will be incorporated into the FGS.