Hybrid Propulsion Transfers to the Moon

This work analyzes special Earth-Moon transfers that make use of both chemical and solar electric propulsion. A first high-thrust, low-Isp impulse is used to place the spacecraft into an exterior-like low-energy transfer to the Moon, possibly performing a lunar gravity assist. The subsequent use of low-thrust, high-Isp propulsion makes it possible to perform a lunar ballistic capture leading to a final, low-altitude orbit about the Moon. Hybrid propulsion transfers outperform both the chemical transfers (Hohmann, interior, and exterior) and the fully solar electric propulsion transfers (e.g., SMART-1-like) in terms of propellant consumption, although an assessment of these transfers at system level is still missing.