Future Propellants for Launch Vehicles—Metallic Hydrogen with Water and Hydrocarbon Diluents

Earlier papers have shown that the energy released from recombination of the atomic hydrogen formed when metallic hydrogen is raised above the critical metastabability temperature yields a far greater specific energy and specific impulse than the combustion of hydrogen and oxygen. Experimental efforts continue towards the challenging goal of producing metallic hydrogen in the laboratory. Progress in 2009 has significantly extended the hydrogen high pressure melt line, a path towards metallic hydrogen. The temperature of the recombination reaction of pure metallic hydrogen will be much higher than existing rocket engine materials can withstand. The approach examined here is to dilute the metallic hydrogen, lowering the reaction temperature. Water, hydrocarbons, and liquid molecular hydrogen diluents are shown to provide an attractive specific impulse without exceeding acceptable material technology temperature limits. Analysis of a two‐stage mission to the lunar surface with a liquid hydrogen diluted secon...