This device, made by the Barnes Instrument Company, was used to assist a Mercury astronaut in locating the Earth's horizon, relative to the attitude of a Mercury capsule. An accurate determination of the horizon was considered a good human backup to orient the craft for a return from orbit, in case the automatic control systems failed. This is probably an unflown specimen.
Transferred from NASA to the Museum in 1977.
Transferred from National Aeronautics and Space Administration