This is a 4AS-1000 Mk. 2 JATO (Jet-Assisted-Take-Off) rocket motor, developed and constructed by the Aerojet Engineering Corporation for helping to lift heavily loaded planes and for rescue work. The motor produced 1,000 pounds of thrust for four seconds. The 4AS-1000 dates to 1953, and was a modification of the 14AS-1000. Due to its short duration, the 4AS-1000 was not as widely used as the standard 14AS-1000.
When the 4AS-1000 appeared, Aerojet was becoming one of the world's leading developers and producers of liquid and solid fuel rocket motors for a wide variety of applications, from boosters, to missile power plants, sounding rocket motors, and launch vehicle engines, plus many miscellaneous applications.
Aerojet General donated this JATO Unit to the Smithsonian in 1968
Gift of the Aerojet General Corporation