High-pressure-pumped hydrazine for Mars sample return

A monopropellant single stage can lift geological samples from Mars to orbi t. The proposed propulsion system uses previously demonstrated miniature pu mp-fed hydrazine technology. Loading the propellant just prior to operation avoids the prohibitive structural, thermal, and safety constraints that ex isted during earlier mission phases. A 100-kg Mars liftoff mass is 86% hydr azine, < 6% propulsion hardware, and > 6% payload and guidance. The useful mass delivered to Mars can be increased by also using pump-fed hydrazine fo r landing.