"Buck Rogers XXVc: Countdown to Doomsday", 1990.

My understanding is that this is a relic from a dark time in the RPG business, when a tiny seed of uncertain rot planted at the very founding of TSR, before anyone thought D&D had any commercial promise, germinated into a full-blown attempt by a hostile outside interest (in this case, the estate of the creator of Buck Rogers or "The Dille Family Trust") to refigure the thriving business into a house organ for an unrelated and somewhat basically incompatible outside intellectual property... or at least to divert and misallocate funds from the business to the estate until the business was spent, exhausted and deflated. Quick, while Gygax is distracted in Hollywood making Saturday morning cartoons!

Spectacular Inter-Galactic Battles

Blast into the future for hours of adventure.

Join Buck Rogers and the New Earth Organization in the exciting 25th Century, and play the BUCK ROGERS XXVc Role-Playing Game and Countdown To Doomsday, the new computer role-playing game.
The XXVc role-playing game is packed with adventure, fantastic civilizations, genetically-engineered races, and future-science technology. This game contains action-packed adventures sure to thrill science-fiction fans and game players alike.
The computer game thrusts you into a race to save humanity from the enemies of the inner planets. Players must follow clues across the solar system, through the space ways, and to the surfaces of Mars, Venus, and the orbiting satellites of Mercury to discover the awesome DOOMSDAY Device.
Earth's future is in your hands! Look for these games at book, computer, hobby and comic stores everywhere.

Maybe I'm just cynical, but I suspect that any product sold at book, computer, hobby AND comic stores is unlikely to satisfy any of their regular patrons.
You can't see it here (an absence of screenshots always a conspicuous omission), but playing the Buck Rogers CRPG on SSI's venerable Gold Box engine was a really jarring experience: some might disagree (eg. Bioware, Raven) but you can't just re-skin a fantasy game engine as sci-fi (or vice versa) without knocking some people for a loop. The engine was getting long in the tooth by this point (it had been quite some time since it launched with Pool of Radiance) but by all accounts this fundamentally misguided product was nonetheless a solid, workmanlike effort.