The initial concept was that, faced by the destruction of Earth, a multigeneration starship had been built. The ship contained dozens of self-contained biospheres, miles across; each one containing people from a different culture. Early in the voyage, disaster struck, and the command section, with its crew, was destroyed. Centuries later, the story opens with a young man in the Amish biosphere making a discovery that the world is far larger and mysterious than he had realised: he finds his way into the service areas of the ship, and discovers its history. The ship is now only a few years from its destination: the (lost) alternate command bridge needs to be found, somewhere on the vast ship, and preparations made for arrival.
The scenario drew on common themes in science fiction; it had the obvious potential for an interesting, developing storyline as more discoveries were made about the ship, and other, previously isolated cultures contacted in other biospheres, and Ellison found a company keen to produce it. As things progressed however, he grew increasingly disenchanted, as the producers progressively "dumbed down" the story, cut budgets and changed crucial details. By the end of production, he was so disenchanted with the whole business that he, as was his right, used his alternate registered writer's name of "Cordwainer Bird" on the end credits: this was a signal to anyone who knew him to show how disgusted he was with the whole business.
The show aired, to uniformly bad reviews, and flopped. Ellison received a Writers Guild award for Best Original Screenplay in 1974 for the original script. A novelisation of this script by Edward Bryant, Phoenix Without Ashes, was published several years later; this contained an afterward by Ellison describing what had gone on in production.
The science fiction author and editor Ben Bova had also been taken on by the production company, as a science advisor. His complaints were not as loud and bitter as Ellison's, but a novel by him published shorlty after, entitled The Starcrossed, depicting a scientist taken on as a science advisor for a (terrible) science fiction series suggest that he was not well pleased with what the producer had done.
In this context, the announcement some years later, by the producer of Babylon 5, that Ellison was going to be the advisor for that series was an indication to science fiction fans that, for once, there would be a serious attempt to do science fiction properly on television. (Ellison was listed on the credits for Babylon 5 as himself, rather than Cordwainer Bird)