- Jul 25, 2019
Each of the 18 primary mirror segments have 7 actuators: 6 at the corners and a radius of curvature (ROC) actuator. The secondary mirror has no ROC. The commands to move the mirrors come from an onboard Java Script engine, which is preloaded with visit files from ground. The movements for the mirrors are determined by a wavefront sensing subsystem and mirror control subsystem. The commands to move the mirrors are part of visit file to perform science and collect images. The visit files will issue commands to slew the telescope to the desired location, perform instrument configuration, wait for the telescope to settle from its move, and then perform science based on activity scripts. Images are stored on data recorder and downlinked via DSN during daily contacts via Ka band.Each of the mirrors can be moved with incredibly fine precision, with adjustments as small as 10 nanometers (or about 1/10,000th of the width of a human hair)
The gold is only a few layers of atoms thick. It is on some space age material that flexes at these temps.