Hydrogen Powered Rocket

Liquid hydrogen and oxygen powered rocket is a dream of zero emission space enthusiasts. Ariane 6 has such engines that work with liquid hydrogen and oxygen. However, the rocket utilizes at least two solid boosters during takeoff. The hydrogen powered engines alone do not produce enough thrust to lift the rocket from the ground.

I am in favor of multi-staged rocket design where the first stage simply takes the rest of the stages above the Kármán line. As a result, the rest of the stages accelerate only in vacuum without any air drag. Horizontal only displacement of the first stage simplifies the first stage recovery on the launch platform. Very slow acceleration toward the Kármán line reduces the drag on the rocket. Therefore, allowing large diameter rockets to be build. At the moment all space rockets have high aspect ratio with a narrow base. The design I propose has a very large diameter and short height. The problem with hydrogen is its low density. In order to make such rockets feasible the fuel tanks should have very low weight. Doubling the diameter of a tank doubles its weight, but quadruples its volume.

For the casing of the rocket, I propose a thin sheet of magnesium covered with carbon fiber fabric then filled with magnesium inside a sliding mold. An old shipyard can be modified to construct such a rocket. The idea is to use molten magnesium instead of epoxy used in carbon fiber parts. This would allow a light weight and strong unibody rocket stage to be build. Magnesium is very strong, light and melts at relatively low temperatures. Sliding molds used in concrete buildings can be adapted.

Large base diameter of the rocket would also allow more engines to be placed on its bottom. Allowing the rocket to achieve enough thrust on takeoff without requiring solid boosters. Large diameter of the rocket also allows large diameter payload bay. Therefore, large telescopes or space modules can be deployed to orbit. Additionally, the satellites wouldn’t need folding mechanisms to reduce their volume to fit narrow payload bays.