This device was used by the American rocket pioneer Dr. Robert H. Goddard (1882-1945) during the period 1924-28 to determine the feasibility of ion propulsion for space travel. Ion propulsion, in which electrically charged particles of atoms called ions are discharged, produce extremely high exhaust velocities. Because of that and potential long duration of operation, ion engines are ideal for deep space propulsion. However, ion engines produce very low thrust and must be placed in space by conventional rocket boosters. Experiments in space with ion propulsion first took place in 1964.
According to a 1964 note by Russell B. Hastings, who helped Goddard with his experiments as a graduate student in physics at Clark, this tube was part of a "collection of the parts for use with tube marked C." Mrs. Goddard gave this artifact to the Smithsonian in 1965.
Gift of Mrs. Robert Goddard