This is an experimental sun-follower that uses an externally adjustable mirror (a heliostat) designed for the Aerobee sounding rocket in the early 1950s at the Naval Research Laboratory. This device was intended to stabilize an image of the sun from a spinning and pitching sounding rocket. It used a servo-driven mirror flanked by small electric eyes that would seek out and hold the sun during the flight. The mirror would then reflect the sunlight continuously to instruments such as a spectrograph within the rocket's interior. It incorporates many interesting features, including the heliostat design and the features intended to produce a compact servo-driven device that had low inertial properties. It was superceded by a more robust design from the University of Colorado that was used in many Aerobee flights.

Transferred from the Naval Research Laboratory to the Museum in 1984.