And this time they mean it: CBS and CBS All Access finally have a launch date for “Star Trek: Discovery” — it’s Sept. 24, when the series’ hour premiere will air on the network and streaming service.

In other launch details, CBS announced that “Discovery” will subsequently be available only for All Access subscribers. The 15-episode season will also be released in two separate “chapters,” the first streaming through Nov. 5, and the second resuming at a still-to-be-determined date in January 2018.

This launch marks the third time CBS has set a date, only to reverse course when the deadline approached. The network offered reasonable explanations each time (complicated casting issues and the departure of showrunner Bryan Fuller). Nevertheless, fans did begin to get a little uneasy: Could this latest chapter in the landmark TV series already be snakebit?

“Discovery” was first set to launch in January, but as that deadline approached, CBS indicated a May start date as Plan B. When that was scotched, a statement read, “We’ve said from the beginning it’s more important to do this right than to do it fast. There is also added flexibility presenting on CBS All Access, which isn’t beholden to seasonal premieres or launch windows.”

There could certainly be an all’s-well-that-end’s-well postscript to this. All Access does have a successful original production in “The Good Wife” spinoff “The Good Fight,” conceivably taking pressure off “Discovery” to get ready sooner than later. Few fans would argue with the “do it right” mandate, either. Nevertheless, there were industry rumors late last year that the production was tangled in creative turmoil, script rewrites and casting challenges. When Fuller left, ostensibly to work on Starz’s “American Gods,” the production was left with a general outline and scripts. But Fuller has a highly idiosyncratic style, and the replacement production team was likely forced to start from scratch.

The all-new “Discovery” does have an intriguing cast, with “The Walking Dead’s Sonequa Martin-Green playing one lead, Discovery First Officer Michael Burnham. Michelle Yeoh is Captain Philippa Georgiou of another ship, the Shenzhou. James Frain plays Sarek, the Vulcan astrophysicist best known as father of Spock. Jason Isaacs (“Harry Potter’s” Lucius Malfoy) is Captain Lorca, commander of the Discovery. Martin-Green’s character has long been billed as the commander of the Discovery, so there is a question about how long Isaac’s Lorca will be around.

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As for what the show is about, here’s what CBS has been saying: “ ‘Star Trek: Discovery’ will follow the voyages of Starfleet on their missions to discover new worlds and new lifeforms, and one Starfleet officer who must learn that to truly understand all things alien, you must first understand yourself.”

CBS had hoped to get this rolling on the 50th anniversary of “Star Trek” last year. Instead, 51 will have to do.