Radio Astronomy Explorer Satellite Damper

Scarce ferrofluid viscous damper developed by the Avco Space Systems Division for application on NASA’s Radio Astronomy Explorer (RAE) satellite. The damper measures 8.75" x 5" x 3.75" and is set on a wooden 5.75" x 9" x 1" display base with Avco plate. In fine condition, with scuffs to accompanying original wooden storage box, which measures 8" x 10.5" x 6.5", and notable wear to leather carrying handle.
The ferrofluid viscous damper consists of a small quantity of magnetic fluid hermetically sealed in a vane mounted on the central body of the satellite. The ferrofluid is acted upon by a permanent magnet mounted on a long damper boom. Relative angular motion of the damper boom with respect to the satellite central body produces magnetic force on the ferrofluid causing the fluid to dissipate energy by flowing through a constriction in the vane. Operation of the device resulted in smooth fluid damping with no residual oscillations in contrast to devices wherein mechanical friction is present.
First launched on July 4, 1968, the Radio Astronomy Explorer investigated low frequency (long wave-length) radio emissions from the sun and its planets as well as galactic and extragalactic sources.