Paper [1] quotes the system's efficiency at 1.2 mN/kW.<p>Hall thrusters, a propellant-throwing electric engine, perform at 60 mN/kW. Non-propellant systems like light sails, laser propulsion and photon rockets perform around 0.0033 to 0.0067 mN/kW.<p>If it works, this isn't how you get people to Mars. It's how you move cheaply freight (and probes) around (and out of) the Solar System.<p>[1] <a href="https://regmedia.co.uk/2016/11/09/q_thruster.pdf" rel="nofollow">https://regmedia.co.uk/2016/11/09/q_thruster.pdf</a>