[LucianG]

I believe the C.O.R.A. equipped recon Viper in The Long Patrol was said to be "the fastest ship" in that part of the galaxy or something similar, with a speed at or approaching light speed. It had its laser generator removed so modifications could be made to the engines. If the compression engine theory was adopted, the mods could have been that the recon Viper was equipped with compression engines which were used to speed its approach to the prison planet.