Otto Berg's flight spare of a cosmic dust detector experiment built for Wernher von Braun's Jupiter-C research and development launch vehicle, identical to the unit actually carried as part of the experiments package on a Jupiter-C launch. The device measures approximately 7″ in diameter and 10.5″ long, and features a mirrored circular sensor at one end, with electrical connector ports at the other. The sensor features three layers of material—two titanium layers separated and insulated by a silicon oxide layer—upon a quartz cone, each layer being about one-millionth of an inch thick. There is voltage between the two conducting layers and when a particle of cosmic dust—whizzing through space at 40,000 miles per hour—hits the surface, it momentarily causes a short in the circuit and initiates a signal. The housing of this spare unit is marked in black ink, "#2." In fine condition. Berg holds the patent for this type of 'capacitor sensor' (U.S. Patent No. 3,307,407), and the system formed the basis for the Lunar Ejecta and Meteorites (LEAM) experiment deployed on the lunar surface on Apollo 17, as well as for cosmic dust sensors on the Pioneer 8 and Pioneer 9 sun-orbiting space probes.
From the collection of Dr. Otto Berg.