This is a detector system for a UV photometer for non-solar sources flown in Aerobee rockets from 1955 through the early 1960's. The parts include the mirror, calcium fluoride filter, and gas gain ionization chamber. This artifact is part of a collection of high energy detectors from the Naval Research Laboratory (see A19880001000-19880017000).
It was transferred to NASM in 1987 and is currently stored at the Garber facility.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.