The showrunners of Star Trek: Discovery have hinted that there may be some major character deaths in store for viewers. These days fans often watch episodes of TV shows worrying about the fate of their favorite characters and any cruel demises that may occur. Apart from a few very notable occasions, Star Trek fans have mostly been spared from unexpected deaths of the leads in the films and shows. However with Discovery already being classed as a bigger and grittier Star Trek series, it seems that it might not be prudent to get too attached to certain characters.
The long-running trope of nameless crew members wearing Federation "Red Shirts" and being more susceptible to dying, is a never-ending meme in Star Trek. That said, there have been some iconic deaths in the franchise. Leonard Nimoy's Spock died heroically in Star Trek II: The Wrath of Khan, but the popularity (and change of heart by Nimoy) meant that he was resurrected in Star Trek III: The Search for Spock. By comparison, deaths of major characters in any of the TV shows is mostly rare.
Perhaps the main exception was the sudden and unexpected killing of Tasha Yar (Denise Crosby) in the first season of Star Trek: The Next Generation. This occurred mostly because Crosby wanted to leave, but did create some interesting repercussions and plot twists in later seasons. Other examples include Dax (Terry Farrell) on Deep Space Nine and Trip Tucker (Connor Trinneer) on Enterprise. Arguably though, there wasn't a great deal of emotional impact with these (Dax sort-of returned and Trip passed in the final moments of the show).
Speaking to EW, Discovery showrunners Aaron Harberts and Gretchen J. Berg have stated that major characters in Discovery will not be safe. They could be killed off at any time and their mortality won't be taken for granted. Some of the reasoning for this is laid at the feet of successful series like Game of Thrones. Speaking in an interview, Berg and Harberts said:
"Game of Thrones changed television, They almost made it difficult to fall in love with people because you didn't know if they were going to be taken away from you. That show had an influence on all TV dramas that have come after it .... Death isn't treated gratuitously on this show. It's not for shock value. But when it happens we want to make sure that people really feel it."
It's a fair point, as most current serious TV dramas also adopt this attitude. Along with Game of Thrones, The Walking Dead is also notorious for teasing the demise of lead characters to great (or not) effect. Still, at least Berg and Harberts have clearly stated that it won't be used for "shock value" and any losses will have long-lasting repercussions for the crew and characters.
We already know that the new series will ignore a previous longstanding Star Trek rule by including interpersonal conflict, and that the focus of the story will be on Commander Michael Burnham (played by The Walking Dead actress Sonequa Martin-Green), as oppose to Jason Isaac's Captain Lorca or any other high-ranking officer. Given these hints and all other information, the next journey on a Federation starship could really be exploring new frontiers.
Star Trek: Discovery debuts September 24, 2017, on CBS, with the remainder of the first season streaming on CBS: All Access.