Abstract: A horizon sensor for spacecraft utilizes two or three telescopes, each imaging upon a linear array of pyroelectric elements. The telescopes are pointed at the earth's horizon and the transition or midpoint angle between earth and space is determined in processing the output signals from each pyroelectric array. Low cost and versatility are provided with great accuracy due to, for example, use of a 32 element pyroelectric array. Such pyroelectric material is also tolerant of temperature changes and inertial forces.

Abstract: A thin film bridge initiator is mounted on a header for use in a detonator where a primer is activated by heat from the thin film. The initiator includes a substrate which carries a pair of metallic beam-type leads connected by a thin film bridge which activates the adjacent primer. The beam-type leads are affixed (welded) to a pair of electrical pins which are on adjacent sides of a slot in the header. The entire structure is very cost effective, reliable and provides fast functioning and safety. In addition, a process of manufacturing several bridge initiators at one time on a single wafer is provided.