Coarse Alignment of a Segmented Telescope Mirror

A method of coarse alignment has been proposed for a primary telescope mirror that comprises multiple segments mounted on actuators that can be used to tilt and translate the segments to effect wavefront control in increments as fine as a fraction of a wavelength of light. The method was originally intended for application to the Next Generation Space Telescope (NGST), which will have an aperture about 8 m wide and will include nine primary-mirror segments (a central segment and eight outer segments). The method could also be applied to other lightweight telescopes that are similarly designed to rely on active wavefront-control systems instead of traditional massive structures to ensure high optical quality.