How long does it take to travel from the Imperial Star to the Alien Planet?
Without Transition Gate technology, whether it is the speed of the Federation's or Empire's spacecraft, it would take tens of thousands of years to traverse several dozen light-years. Even using faster vessels, such as the Federation's Single Soldier Starship, without considering energy and the various materials needed for manned travel, it would still take nearly ten thousand years to traverse.
This far exceeds the existence time of human civilization and Empire civilization.