RetroReflector Array (RRA) Characteristics: The retro-reflector array consists of three corner cubes in a linear array with the two outer corner cubes pointing at 45 degree angles relative to the central cube. The central cube is made of fused silica and has a two-lobe Far Field Diffraction Pattern (FFDP) providing nearly equal intensities for compensated and uncompensated velocity aberration. Both outer reflectors have aluminum coating on the reflecting surfaces and near-diffraction-limited FFDPs. One of the end reflectors is made of fused silica with an index of refraction of 1.46 and should provide partial compensation of the velocity aberration. The other end reflector is made of fused glass with an index of refraction of 1.62 and should provide a perfect compensation of the velocity aberration.