Where there are hydrocarbons, there can be jet fuel, and the Air Force is looking at an 85-year-old technology to solve a modern problem. Jet fuel is made from oil, some of which must be purchased from other countries (and occasionally expended in the defense of and acquisition of same, according to some). The Air Force wants a guaranteed supply of fuel to meet its objectives and is looking at the work two German scientists did in the 1920s for answers. Franz Fischer and Hans Tropsch figured out how to make a diesel-like (or JP-8-like) liquid fuel from natural gas, coal and even oil-refinery byproducts. Using iron or cobalt as a catalyst, the process takes the carbon monoxide and hydrogen from a controlled burn of the raw material and creates liquid hydrocarbons of various grades, from the synthetic fuel, to lubricants, to wax. Coal-rich but petroleum-poor Germany had 25 plants producing a total of 124,000 barrels a day by the end of the Second World War. The U.S. has vast reserves of coal, natural gas and oil shale capable of guaranteeing a domestic supply of strategic fuel for hundreds of years, say some estimates.