Chemical Propulsion System Design for a 16U Interplanetary CubeSat

Stand-alone interplanetary CubeSats to Mars require primary propulsion systems for orbit manoeuvring and trajectory control. The context is a 30 kg 16U Interplanetary CubeSat mission on a hybrid high-thrust & low-thrusttrajectory utilising a Dual Chemical-Electric Propulsion System to achieve Earth escape (high-thrust) and perform autonomous deep-space cruise (low-thrust) to Mars. Mission analysis is performed to estimate the required V( 445m=s) for Earth escape and Mars circularisation, and calculate the required thrusts and burn durations while minimising gravity losses, Van Allen belt crossings, and irrecoverable destabilisation. Design of an ADN-based monopropellant thruster and an Ethanol-H2O2 based bipropellant thruster are performed and the critical design details regarding propellant characteristics, system sizes, operating pressures, material selection and geometry of feed systems, thrust chambers, and nozzles are delineated. Performances analysis of the monopropellant thruster yields a maximum thrust of 3.18 N (two thrusters with 1.54 N each) and an Isp = 259.7 s with nozzle area ratio of 100.Similarly, the bipropellant thruster yields a thrust of 2.91 N and an Isp = 303.15 s. The overall mass and volume of the monopropellant system are 5.6 kg (18.7%) and 7U, respectively. The bipropellant system weighs 4.85 kg (16.17%)while occupying 6.5U space.