Technical and economic efficiency of employing a reusable space tug based on a nuclear electric propulsion system to support intensive cargo traffic for lunar exploration

The paper describes math models and parameter optimization results for a reusable Hercules-type space tug based on a nuclear electric propulsion system using as its objective function the total mass of the payload delivered from Earth orbit to lunar orbit over the space tug life determined by the life of the nuclear power unit, and unit cost of delivering from Earth to lunar orbit a unit of payload mass. Considered as parameters to be optimized are electrical power, specific impulse, thrust, propulsion system mass, and time in transit, as well as the number of trips the tug has to make to support the specified cargo traffic.