Blake's 7 was created by veteran television writer Terry Nation and was pitched to the BBC as a kind of "Dirty Dozen in Space." The Beeb liked the idea and production on the series started in 1975.Admittedly, the special effects were below-par, compared to million-dollar US television budgets of today, but keep in mind this series came out just after Star Wars blew everyone away.
The original crew was a motley collection of neer-do-wells: Avon, the computer wizard, wanted by the Federation for grand larceny, Jenna, a space smuggler, Gan, a former prisoner whose violent impulses were controlled by a "limiter" impanted in his brain, Cally, and alien telepath, Villa, the cowardly thief, and Blake,leader of the group who was framed and sent to prison for speaking out against the Federation. The seventh character was the Liberator's semi-sentient computer, appropriately named Zen.
What Blake's 7 lacked in SFX, it made up for in writing and character development. After Star Wars premiered, the producers of Blake's 7 knew they could never compete, but they pressed on anyway and created a program that ran three years and attracted 10 million viewers every week. The show was never campy. It took itself seriously and was often dark and edgy. Low-budget as it was, it made its mark on sci-fi. Today, Blake's 7 enjoys cult status with many fans worldwide, much like Doctor Who which was never known to be cutting edge in its production, but was popular across the globe.