Pioneer Vessel

Pioneer vessels are specialist unmanned craft capable of exceedingly fast acceleration and deceleration using advanced anti-matter catalysed fusion drives. Reaching accelerations of over 5 gees, their substantial fuel stores allow them to sustain this for half of their voyage, flipping their drives and decelerating for the remainder. Assuming no issues in their mission, a Pioneer can manage relativistic speeds, transporting their KHE cargo to the destination.
The majority of the mass of a Pioneer Vessel is devoted to propellent for its drive, and the layered collision shield that is needed to protect the craft from small dust particles that gain substantial kinetic energy at the velocities the craft reaches.