No, beyond the initial propellant. The projectile accelerates constantly (hand waving here) so it's a constant force on the origin (relative mass should make th

No, beyond the initial propellant. The projectile accelerates constantly (hand waving here) so it's a constant force on the origin (relative mass should make this a wash), whereas the projectile enjoys exponential velocity. Two minutes is pretty short, I'm actually blown away. If only we could all charge our electric vehicles that quickly.