Requirements for air-breathing electric propulsion in low-altitude orbits

This perspective overviews the requirements to operate air-breathing electric propulsion (ABEP) systems in low-altitude orbits. We highlight the needed scientific advancements to realize these technologies including innovations at the intersection of electric propulsion, gas dynamics, air chemistry, and material science. In addition, we describe specific scientific and technological challenges that constrain the operation of ABEP systems. These include the collection and compression of atmospheric propellant, producing enough thrust to counteract drag, generating and sustaining plasmas, satisfying the power requirements to maintain orbit, operating with minimal flow rates of propellant, passivating materials, and understanding the effects of air chemistry. Finally, we offer an outlook on the future of ABEP systems and how they can influence the optimization, efficiency, and capabilities of future missions in very low Earth orbit.