Energy management in rocket propulsion

The optimal management of the available energy in an ideal single-stage rocket produces a velocity increment that is larger than the value provided by Tsiolkovsky's equation. This result is immediately applicable when a limited amount of energy is available from a source that is external to the propellant. A storage device is instead necessary to delay partially the use of the energy that is produced by the combustion of a reactive working fluid. The penalty of the energy-source mass and the presence of an upper limit on the propellant temperature are also discussed; in the latter case, the addition of a low-molecular-weight, inert propellant to the reactive propellant is beneficial during the final phase of the rocket acceleration.