Positioning and maintaining alignment of the corrective optics for the Space Telescope is the objective of the COSTAR Optical Benches. The fixed and deployable Optical Benches are graphite/epoxy structures to achieve the alignment requirements. The optical benches are comprised of various cross section tubes and flat panels. Layups are designed to meet specific material properties, one of which is near zero CTE. Precision CTE measurements are necessary to ensure mission success. Eastman Kodak performed all developmental and acceptance CTE testing of the COSTAR optical benches. The apparatus used to perform the precision CTE measurements is described. Three test sets were used. A laser based, single coupon test and a multiple coupon LVDT based system performed the coupon tests. A proprietary Universal Tube Tester was used to measure the CTE of 80' rhomboid cross section tubes for flight use. Uncertainties of 0. 02 ppm/ degree(s)F were achieved. Typical COSTAR test results are discussed, including graphical data for all three test configurations.