Test section of a later coaxial version of a Hall-current plasma accelerator. The technician is wearing goggles to protect his eyes against the intense light created by the very bright, high-velocity plume from the MPD arc-jet exhausting into a vacuum tank. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995), p. 137.
