Reply #9: The beauty of the mass-drive is you can launch anything with it,

[kentauros]

so long as it can be moved through the magnetic field. That can be achieved simply with a ferrous casing as a carrier. The highest acceleration I've seen of our current technology in this device was something like 300,000 Gs. Yeah, three-hundred-thousand times the force of one Earth gravity! :o

As for the PPG, you'd probably have to talk to JMS, the creator of B5, about the feasibility of them. Although, within the series, many of the people at JPL loved the http://babylon5.wikia.com/wiki/SA-23E_Mitchell-Hyundyne_Starfury">Starfuries, their individual fighters, possibly due to their maneuverability. They might be able to better explain how a PPG could work :D