I have done this with games, make it a fusion rocket, and use pp fuel for jump.
ISTR the Buck Rogers TV program was post nuclear apocalypse, the original comic was different. Whatever the meta-story, the players need something closer to connect with.
They don't have to role up a character for Buck Rogers and play him, the 1970s Buck Rogers television show is the main inspiration for this game, but the game of course revolves around the players not Buck Rogers as a character. I just received the Core Rules book today, so now I got a set of rules and can role up a Buck Rogers character if I want, according to the rules Buck Rogers would be a Navy Fighter Pilot, he lived in the Mid 21st century in this scenario, a nuclear war occurred when he was out in space onboard his long range fighter, the fighter comes with a low berth, this being a new technology that is employed by the military for the first time, a form of hibernation to help the crew conserve life support resources and travel long distances to reach the asteroid belt.
The asteroid belt is of interest because asteroids can be used as weapons, if one hits the Earth it releases as much energy as a nuclear bomb but without the radiation or the fallout. The two main superpowers that existed in Buck Roger's time were the United States of America and the People's Republic of China, Russia was China's Junior Partner, while NATO was aligned with the United States and Japan, the Cold War moved out into space, and Buck Rogers was one of those strategic pilots, he got into combat with a Chinese space fighter, he won the engagement, but his ship was crippled, and this far out from the Sun it gets very cold, with his life support failing Captain Buck Rogers had no choice but to climb into his low berth to await rescue, the fact that there was a nuclear war going on Earth at the same time meant that rescue was 441 years in coming.
The first person Buck Rogers saw when he woke up from hibernation, besides a technician was Princess Ardala. The technician arranged for Buck Rogers to be awakened by injecting a stimulant into his bloodstream when Princess Ardala was there. Buck was not sure what to think when he saw the princesses face for the first time, she was holding a communicator which translated Draconian into mid 21st century English, Earth also was not what he remembered it being, and he had to go through all sorts of cultural and technological shock when he was brought back to Earth by the princess.
Buck misses his country and the wife and child he left behind dearly, what existed on Earth when he got back was not quite the same. Buck was in mourning, he looked for records about what happened to his family during that nuclear war, but the nuclear war destroyed a lot of records, and he could not be sure if they survived or not. The Earth descended into savagery over the next century and a half after than nuclear war, and then slowly climbed out of it and colonized space, the wormholes were discovered when a Draconian armada exited from one and discovered Earth.
The Draconians are humans that are descended from Earth humans that propagated through space by slower than light travel, when they discovered the wormhole network, they set about building the Draconian Empire, the Earth proved not so easy to conquer, the Earth forces put up a fight and the first war between Earth and Draconia ended with an armistice, but the Earth paid a heavy price in repelling the Draconians, thus when Buck was revived from his centuries long slumber, there were many people on Earth that were interested in signing a peace treaty with Draconia. The Draconians occupy Mars, that is their one conquest in the Solar System, and Ardala was placed as the titular ruler of Mars in the aftermath of the Earth-Draconian War.