The Progressive Rocket

Based on the ideas I proposed earlier, I would like to define the progressive rocket I mentioned previously. The objective of this rocket is to utilize earth’s atmosphere for the reusable first stage of the rocket. As a result, the first stage will have wings and additional ramjet engines to assist the rocket engines.

The first stage of the rocket will utilize RP1 as fuel and LOX as oxidizer. The rocket will takeoff like a plane from an airfield. Initially, the rocket engines of the first stage will be fired. This will give fast acceleration to enable shorter take off. When the rocket reaches minimum speed for ramjet to operate, the ramjet engines will be fired and some of the rocket engines will be shot down for efficient flight. Plane like takeoff will require much less thrust compared to a vertical one. Therefore, there will be fewer engines on the first stage. Also, the engines will not be throttleable and will not have gimbal. The ramjet engines will have thrust vectoring. During takeoff ailerons will be used.

Ramjet nozzles will have regenerative cooling which will preheat liquid oxygen before being injected into the ramjet engines. At low altitudes, ramjet engines will utilize external oxygen. As altitude increases, liquid oxygen will be injected to maintain thrust. The air entering the ramjet will be accelerated by the exhaust gases which will increase its efficiency compared to a rocket engine even at higher altitudes. However, most of the thrust will still come from the rocket engines.

The wings of the rocket will enable it to takeoff with much less thrust compared to a vertical takeoff. The lift generated by the wings will also reduce the thrust lost to counteract the gravity. Additionally, the wings coupled with ramjets will reduce the fuel requirement for the return to base flight. It will be also much easier to land the first stage of the rocket with wings. The first stage of the rocket will be like a biplane. Unlike traditional wings that are thick to generate lift. These wings will be thin to reduce drag. Airlift will be generated by angle of attack. Thin vertical sections supporting the wings will double as vertical stabilizers. The upper stages of the rocket will also have much smaller wings to improve the stability of the plane.

The first stage of a rocket usually reaches Mach 8. Ramjets cannot operate efficiently at those speeds. The engine would need to transform into a scramjet during flight. If that wouldn’t be possible the flight trajectory and final speed of the first stage would be adjusted accordingly.

The previous attempts on this idea tried to come up with a magical engine that would do everything. However, I propose the existing engines which would support one another to improve fuel efficiency.