Interplanetary CubeSats enable universities and smallspacecraft- consortia to pursue low-cost, high-risk and highgain Solar System Exploration missions, especially Mars; for which cost-effective, reliable, and flexible space systems need to be developed. Missions to Mars can be achieved through a) in-situ deployment by a mothership and b) highly flexible stand-alone CubeSats on deep-space cruise. The current work focuses on sizing and establishing critical design parameters for dual chemical-electric propulsion systems that shall enable a stand-alone 16U CubeSat mission on a hybrid high-thrust & low-thrust trajectory. High thrust is used to escape Earth whereas low-thrust is used in autonomous deep-space cruise, achieving ballistic capture, and emplacement on an areosynchronous orbit at Mars. Chemical propulsion characterisation is based on V requirement and a heuristic optimisation of thrust, specific impulse and burn time while balancing transfer time and propellant mass. Limitations are set to minimise destabilising momentum. Electric propulsion characterisation is based on the V, power consumption, and trajectory requirements for fueloptimal and time-optimal strategies. The sizes amount to 16% and 21% of the assumed total mass ( 30 kg) for chemical and electric systems, respectively. @en

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.@en