Abstract

The relay lens for the Johns Hopkins University ultraviolet telescope (HUT) will be used primarily for guidance when the HUT system flies on the Space Shuttle in 1986. It relays the focal plane image of the 1800-mm focal length, f/2 parabolic primary mirror to a vidicon at 2× magnification. The vidicon will display a star image on a TV monitor which will enable an operator to maintain Shuttle orientation. It may also be used to obtain pictures of celestial bodies including possibly, the only pictures of Halley’s Comet. The design problems associated with this six-element plus filters were very severe. For example, it relays the highly comatic, 400-μm spot in the parabola focal plane to a 25-μm spot at the vidicon. The spectral range extends from 0.4861 to 0.6500 μm. The FOV of the primary mirror is 1.5 min but the relay lens must see an input FOV equal to 30 times this quantity because of its 60-mm object distance. This presentation briefly describes the HUT system followed by a detailed exposition of the design problems and ultimate performance of the relay lens parabola combination.

© 1985 Optical Society of America