Liquid Fuels and Propellants for Aerospace Propulsion: 1903-2003

Introduction M AJOR increases in liquid-fueled propulsion performance have occurred in the past 100 years.TheWright brothersŽ rst  ew on 14 December 1903 with an engine that generated slightly more than 130 lb of thrust for  ights that ranged from 120 to 850 ft (Ref. 1). Contrast that with current aircraft such as the Boeing 777, which can  y 8000 n miles, equipped with engines from the GE90 and PW4000 series that generate over 100,000 lb of thrust. The Wright brothers probably consumed less than a gallon of gasoline in that Ž rst day of  ight tests. In 1997, airlines consumedan average of 177 million gal/day of jet fuel worldwide.2¤ Robert Goddard’s Ž rst  ight of a liquid rocket on 16March 1926 reachedan altitudeof 41 ft and landed184 ft from the launchpoint (seeRef. 3). Again, the contrast with current vehicles such as the space shuttle, which can lift over 50,000 lb to 200C miles into low Earth orbit, is dramatic. The intent of this paper is to describe the evolution of liquid fuels for aircraft and rockets as the engines and vehicles they fuel have undergone these signiŽ cant increases in performance.