On the optimization and application of electric propulsion to Mars and sample and return mission

Generally speaking, optimization of trajectory inevitably requires so called Two Point Boundary Value Problem (TPBVP). This is true even for optimizing trajectory using low thrust electric propulsion system, which may have been a tough obstacle that prevents propulsion researchers from searching for applications. However, it may well be validated that placing discrete impulsive maneuver points are approximating finite thrusting arcs if gravitational field is almost uniform. That condition is realized in interplanetary field. What this short paper presents is how TPBVP is avoided by introducing multi-impulse method, where linear analysis can be applied to. The process noted here is capable of incorporating a wide variety of practical constraints on the propulsion elements. Numerical illustrations listed here are comprised of 1) Sample and Return Trajectory to Near Earth Asteroid as well as 2) Trans-Mars Trajectory with Spin Stabilized Spacecraft. The latter example is given for the purpose of demonstrating this scheme's versatility in combining attitude constraint. For researchers' convenience, FORTRAN source code examples are attached to.