 A thrust RMI engine also powered the Viking research rocket, the first large liquid-fueled US high-altitude rocket.RMI was merged with Thiokol in 1958, where it produced the XLR-99 engine that powered the X-15 rocket aircraft.Reaction Motors, Inc. began operation as early as 1930 through the work of then American Interplanetary Society members Lovell Lawrence, George Edward Pendray, Hugh Pierce, and engineer John Shesta.