Lunar Electrothermal Oxygen Rocket

An electrothermal oxygen rocket may be the first means by which product is exported from the moon for a profit. This is not intended to pay off the investment necessary to bring the lunar industrial base to the state necessary for this device, but early returns will give confidence that more substantial returns will be achieved later.

An example lunar electrothermal oxygen rocket flies parallel to the ground between two calcium filled steel tube electrically conductive rails. The rails are held 10 meters above the average ground level and extend forty miles (65 km) down range, straight, level, and parallel to each other. Beyond forty miles two steel rails without calcium fill extend in the same line to a point 60 miles (96 km) down range.

The rocket, made on Earth, has an electrically driven oxygen pump that forces oxygen at high pressure through a resistive heater. The oxygen then flows through an expansion nozzle exiting at 2000 meters per second. The rocket has 40 kg upper stage, 40 kg empty weight, and 120 kg oxygen in the propellant tank. The mission delta v is 1832 meters per second of which 229 meters per second is reserved for gravity loss and 1603 meters per second is stage separation velocity. Average downrange acceleration is 20.1meters per second for 79.9 seconds with stage separation at about forty miles (64) km downrange at which point the first stage begins to brake to a stop by friction, to be reused. Braking friction is provided by locally produced ceramic pads pressed against steel rails. Electric power for the rocket comes from the two rails that it flies between. The power required is 340,000 kilowatts for 80 seconds. The upper stage is a mini ion thrusting spacecraft made on Earth. The cargo in the upper stage is a canister of helium 3. Helium is not yet used for fusion power, but a small amount is used for research at about $4000 per gram. It is conceivable that at this price it would be worth exporting.