Accelerating hypersonic airplanes with ground-power

The possible benefits of using ground power to accelerate the airplane on a launch ramp are quantified. A passenger-carrying hypersonic airplane leaving its loading ramp carries fuel for acceleration, cruise and landing. For example, a 230-passenger plane starting a Mach 5 trans-Pacific flight will be loaded with 80 metric tons of liquid hydrogen, up to 40% of which is burned in generating kinetic energy. Catapulting this airplane to cruise speed with ground power would reduce weight and liquid-hydrogen volume. However, there are limits. A ramp for launching a 150-metric-ton vehicle to Mach 5 with 4 g acceleration would be 38 km long and require up to 10 GW of power. In the final second, 2.8 MWh of energy is consumed along 1720 m of ramp. Possible scenarios and acceleration mechanisms are evaluated