The original "Space Patrol" science fiction roleplaying game by designer Michael Scott, released in 1977 by Gamescience. It was released only as a soft-cover saddle-stitched booklet.
Although not officially licensed, "Space Patrol" made some tongue-in-cheek use of the terminology and setting of Star Trek, referencing Kirk, phasers, Klingons, landing parties and so on. At the same time, its ambitions went beyond Trek-with-serial-numbers-filed and also included references to Niven's Kzinti, Asimov's Foundation, Heinlein's Starship Troopers, Flash Gordon, Pournelle's Falkenberg's Legion and -- in a last minute addenda -- the new kid on the block, Star Wars.
In other words, "Space Patrol" was striving to be a definitive adaption of the space opera genre for RPGs. Space Patrol wasn't the first or only attempt at that time to create a "sci-fi D&D". 1976 had already seen the releases of TSR's "Metamorphosis: Alpha" and Flying Buffalo's "Starfaring"; and Tyr's "Space Quest", FGU's "Flash Gordon" and GDW's definitive science fiction RPG "Traveller" would follow in 1977, around the same time as "Space Patrol" itself.
"Space Patrol" went on to spawn various games over the next few years: Heritage's "Star Trek: Adventure Gaming in the Final Frontier" (1978), Gamescience's "Star Patrol" (1981), and Terra Games' "Starfleet Voyages" (1982). Although each of these are separate RPGs, they are all by co-designer Michael Scott and all undeniably share many of the same mechanics (and, often, the exact same text).
No additional supplements for "Space Patrol" were ever released.
(attribution: description submitted by Robert Saint John based on his own previous articles from his Groknard site, edited and updated)