Well written article I enjoyed :)
When I start my PhD hopefully in collaboration with ESA, I will be investigating precise propulsion systems using graphene. When a photon impinges on graphene at almost every wavelength it will emit an electron with energy and force proportional to that of the photon.
By using high precision lasers and controlling the flux very carefully it's possible to control very precisely a final propulsion. It will be used in the final stages of a manoeuvre.
RE: Basics of Rocket Propulsion - Part 1