Direct Trajectory To The Moon

I would like to continue on my previous article on “Complexity vs Fuel”. This time on the launch trajectory. I would like to propose a new rocket design and trajectory for lunar missions.

The main difference of the new rocket from the rest is its direct ascent from Earth to the escape velocity. After the rockets final stage and the payload reach the escape velocity of earth, it will follow traditional trajectories to establish its mission. The objective of this is to simplify the flight trajectories and more importantly minimize the time spend on lower orbits that contain so much space debris. All the lunar missions start with a circulation of the earth at a lower orbit that is full of lethal obstacles.

The first stage of the lunar rocket will be a classical liquid propulsion rocket that will only fly vertically until it reaches an altitude above the Kármán line. During its flight it will spin slightly to stabilize itself like the bullets. Once its fuel is almost depleted it will release the upper stages and the first stage will return back to the launch site using the remaining fuel and parachutes.

The upper stages of the rocket will not be aerodynamic. Therefore, they will be hidden inside the extended walls of the first stage until they are released in vacuum. The upper stages of the rocket will be similar in design, but gets smaller as the stage increases. The stage will be a cascaded spherical propellent tank and an aerospike nozzle engine at the bottom. The inner tank will be filled with liquid oxygen and the remaining by RP1. Therefore, LOX tank will be thinner and lighter. The nozzle will be fixed. The steering will be done using warm gas propulsion which will be hot oxygen. The liquid oxygen needs to be gasified before burning. Some of this warm gas will be used to steer the rocket. Simplifying the design. The spherical tanks will be painted in black to heat up the propellants to maintain the tank pressure using the sun. The constant spinning will ensure even heating and stability.

Depending on the payload, the upper stages will be two or more. Only the final one will travel with the payload to accomplish complex maneuvers for moon landing. The remaining stages will fall on earth. The vertical trajectory will allow the upper stages to fall close to the launch site. The stages will have parachutes to slow them down. Only the engine section will have high temperature protection. The thinner tanks will melt and protect the engine section from overheating. Once the upper stage is recovered, the engine will be refurbished to be reused.