Expansion of the transport capacity of air-breathing space transports by optimal control of the ramjet-mixing ratio

The influence of the hydrogen-air mixing ratio in a ramjet prolpulsion unit on the transport efficiency of a one-step, reusable space transporter with combined rocket-ramjet propulsion is investigated for a typical mission. The possibility of minimizing fuel consumption in such a transport with optimal mixing control of the propulsion unit is studied. To this end, the flilght optimization problem is numerically solved as a parameter optimization problem. The results suggest a promising potential for combined rocket-ramjet propulsion.