Authors: Hitansh Sharma
Abstract: Propulsion has long been the most difficult subsystem to fit inside a CubeSat. The earliest CubeSats carried no propellant at all — they accepted whatever orbit they were placed in and relied on passive stabilisation to function. That works for simple missions, but it falls apart the moment you need to change your orbit, hold a precise formation, dodge a piece of debris, or come back down in a controlled way. This paper reviews the five propulsion technologies that come up most often in CubeSat mission design: cold-gas thrusters, resistojets, pulsed plasma thrusters (PPTs), electrospray ion engines, and solar sails. For each one, the underlying physics, real performance numbers, flight history, and practical limits inside a CubeSat are examined. The paper then covers delta-v budgeting at the mission level, the regulatory constraints that propulsion adds to a CubeSat program, and where the field is headed in the near term.
