Pulse Shaping in Air-Breathing Pulsed Plasma Thrusters

High specific impulse propulsion is needed for growing mission criteria such as deep space and very low Earth orbit missions where propellant utilization and efficient momentum transfer is essential. Most pulsed electromagnetic thrusters cannot control when propellant is present relative to when current is applied, which restricts their ability to shape acceleration modes and limits mass utilization. Here we address this gap by combining adjustable propellant filling times with programmable current waveforms using solid state closing switch modules. We demonstrate that this approach aids controlled transitions between magneto deflagration and magneto detonation. We also demonstrate clear effects of scaling pulse widths across pulse widths from 50 to 500 microseconds and peak currents from 2 to 8 kiloamperes. High speed imaging, electrical diagnostics, and impulse measurements show that short duration pulses produce collimated plumes and higher impulse bits at fixed energy, whereas longer pulses yield diffuse plumes and reduced thrust. Burst operation with continuous propellant injection maintains repeatable detonation driven acceleration. These results show that independent control of propellant loading and current waveform provides a practical route for shaping electromagnetic acceleration and improving performance in gas fed pulsed plasma thrusters.