Concept Study on New Heavy Rocket with Ejector Rocket Engines

This research examined the concept of a heavy rocket equipped with air-breathing ejector rocket engines as a means of transporting large quantities of supplies into space. The design was based on the Japanese LE-7A engine of the H-2A rocket. These ejector rocket engines can provide large thrust augmentation by re-heating unburned hydrogen with atmospheric oxygen sucked in by an ejector effect. Using a simple analysis of the heavy rocket flight performance, it was found that the air-breathing effect of the ejector rocket engine appeared up to an altitude of 17.5 km. It was also found that a 26% propellant reduction and a 53% payload increase were possible.