Hydrogen: Make-Sense Fuel for an American Supersonic Transport

Liquid hydrogen, as a prospective aviation fuel, can harness the United State's relatively abundant domestic coal resources and, subsequently, nuclear and solar energy to supply air transportation's mounting energy needs. This poses an important strategy leading away from dependency upon petroleum. Hydrogen is applicable to both subsonic and supersonic aircraft with major performance benefits deriving from its gravimetric heating value which is 2.8 times that of conventional jetfuel. Hydrogen's notorious bulkiness and the innate problems posed by a cryogenic fluid are inherent characteristics which—as demonstrated by our Space Program—can be practicably handled in all their aspects, An American second-generation supersonic transport would especially benefit from hydrogen fueling in performance, environmental effect, and in direct operating cost (considering escalation trends for petroleum-based fuels). Striking gross takeoff weight reductions and over-all energy savings of from 20 to 40 % appear certain. Engine pollutants are virtually eliminated. Stratospheric effects of nominally increased water vapor in the exhaust may not be significant; this has not been fully assessed. Marked takeoff noise reductions and sonic boom amelioration are predictable. Coupled with other airplane improvements now being evaluated in the Nation's supersonic technology program, hydrogen may be the needed step-function advancement permitting America to field an unquestionably "better airplane" in the ongoing international supersonic competition initiated by Concorde and the TU-144.