"Today is a good day to die."

So said Worf, more than once, but most of the characters on this list would disagree. Star Trek has seen a lot of death in its fictional universe, and that's even without counting all the redshirts. Captain Kirk himself has died four times within the franchise (if you include the imaginary Vulcan Death Grip), and in various timelines, we saw (or heard about) the deaths of Christopher Pike, Seven of Nine, Deanna Troi, and Data, to name a few biggies who didn't make it onto the final list.

Some of these deaths come with drawn-out scenes complete with tears and swelling music; others are delivered with more subtlety, asking us to contemplate deeper concepts. And some are there simply because we miss them. "Death is that state in which one exists only in the memory of others," said Tasha Yar. Check out the 17 Most Heartbreaking Deaths in the Star Trek Franchise, and have those tissues handy.

17. George Kirk

In the first fifteen minutes of the Star Trek reboot, we meet and then lose George Kirk.

In the Kelvin Timeline, JJ Abrams-verse, Jim Kirk is born in an escape shuttle; less than a minute after his birth, his father is gone, having sacrificed himself for his crew, his wife, and his son. George got to hear his newborn son's first cries, he said goodbye to his wife, he named his child, and then, in a fiery explosion, he was gone.

The character, the timeline, everything shifted in that moment, and its impact would change James T. Kirk forever. James, born of joy and sorrow, would never be the one we knew in the original series. He was born emotionally wounded, and his path, although it would still take him to the Captain's chair on the Enterprise, was forever altered and marked by the tragedy at the moment of his birth. George Kirk's death comes too quickly, as we only get to know him for a few minutes, and at the same time too slowly, as we experience every agonizing moment up to his last.

16. Trip Tucker

Let's face it, Trip Tucker was the most entertaining character on Enterprise, with Dr. Phlox coming in a close second. Trip was bold and brave and fun. Trip had a sense of humor and a sense of adventure. In a relatively joyless show, he brought that sense of wonder and excitement to his missions, but tempered it with his experience; he was never wide-eyed and naive, he was just a true explorer, who couldn't wait to go to a new planet, meet some new people, and discover new technology.

In the much-disliked final episode of Enterprise, Captain Archer saves Trip's life, and then Trip returns the favor ... but the cost is tragic. Trip sacrifices himself for his captain and his ship, and we lose the one guy on that early Enterprise we'd actually want to hang out with. Archer gets him to Sickbay and Phlox does everything he can, but we know from the look exchanged between them in Trip's final moments that it's over. "Trip would be the first to say it was worthwhile," T'Pol tells Archer, and she's right.

We hope there's an alternate universe somewhere with a Trip in it, so we can see him again one day.

15. Amanda Grayson

The first Star Trek reboot gave us better insight into Amanda Grayson, Spock's human mother, than the series did, but it also gave us her death. We see her taking care of Spock as a child, comforting him when his peers and his culture don't accept him, and giving him strength. So it makes sense that when the destruction of Vulcan is imminent, Spock races down to the planet to save his parents, along with anyone else he can.

In a heartbreaking moment, we see the ledge Amanda's standing on collapse just before the transporter beam can get a proper lock on her, and Spock reaches out to her helplessly as she falls to her death. On the Enterprise transporter pad, Spock simply stares at the space where she would've been, his sense of loss palpable, as Kirk and Sulu watch in shocked silence. It marks this new Spock as much as George Kirk marks Jim. Spock did everything you could to save her, and couldn't, and had to live with the knowledge that a few more seconds would have made all the difference in the world.

14. The Horta's Children

"Pain!" This one is classic Trek, with the story of a monster that isn't what it appears to be.

A creature is murdering miners on Janos IV, but she's not a murderer: she's a mother. She's a Horta, and Spock's mind meld with her reveals why she's been attacking the miners: the "silicon nodules" they've been tossing around so carelessly are her eggs.

"Go out into the tunnel. To the chamber of the ages. Cry for the children. Walk carefully in the vault of tomorrow. Sorrow for the murdered children. The thing you search for is there."

Every fifty thousand years, the entire Horta race dies but for one, who lays thousands of eggs to create the next generation. Kirk informs the raging miners that she is both intelligent and peaceful.  "She had no objection to sharing this planet with you," he tells them, "till you broke into her nursery and started destroying her eggs. Then she fought back in the only way she knew how, as any mother would fight when her children are in danger."

What parent wouldn't empathize, and mourn for the ones that were lost?

13. Ensign Sito

There's a very unique episode of TNG called "Lower Decks" that answers the age-old question: what is life like on the Enterprise when you're not a senior officer?

We meet four ensigns, all of whom are waiting to hear about promotions. Among them is Ensign Sito, a Bajoran who was one of Wesley Crusher's Starfleet Academy classmates and who has had to redeem herself for an incident they were both involved in (but that's another story). She's earned the respect of both Worf and Riker, and this gives her the strength to stand up to Picard when he challenges her right to be on his crew. But he's actually faking her out: he needs her for a stealth mission and wanted to evaluate her courage.

She accepts the secret mission, and succeeds, but at the cost of her own life. "Her loss will be deeply felt by all who knew her," Picard tells the crew, when he informs them of her death in the line of duty. Her three friends mourn their loss together in Ten Forward, and are ed by Worf, junior and senior officers united in their mourning.

12. Robert Tomlinson

Why is Robert Tomlinson's death so heartbreaking? What makes him stand out in the pack? It's the fact that at the beginning of "Balance of Terror," an iconic first season episode, Tomlinson is about to get married.

In the chapel, the crew gathers for a happy occasion, as Kirk waxes poetic on the happy privilege of shipmasters to officiate at weddings. Angela Martine and Robert Tomlinson are smiling at each other, ready to say their vows. Next thing you know: red alert. The wedding is postponed.

The Enterprise engages in a battle of wills—and weapons—with a Romulan ship. She wins, but with one casualty: Tomlinson. "The boy who was getting married this morning," says McCoy. Kirk, heavy with responsibility (and in a Janeway sort of moment we don't always see from him), heads to the chapel to comfort Angela. Her heart is broken, and the crew grieves along with her, painfully reminded of the risks they take every day to themselves and those they love.

11. K'Ehleyr

K'Ehlayr was only in two episodes of Star Trek: The Next Generation, but she made her mark. When we first met her, she and Worf already had a romantic history, plus plenty of chemistry, evidence of which returned with he on her second visit, when she showed up with their son, Alexander.

K'Ehlayr was half Klingon and half human, and likely an inspiration for Voyager's B'Elanna Torres. She was smart, she was brave, she was strong, and she was a better match for Worf than anyone he got paired with later. She called him on everything, challenged his blind acceptance of the traditions that led to his dishonor, and refused to marry him just because they slept together.

When she was killed, we lost a great female character, Worf lost his soulmate, and Alexander lost a mother. She was murdered by Duras, and left to bleed to death while Worf and Alexander watched, helpless. Worf's howl, and Alexander's fearful reaction, said it all: this was a brutal death, unfair and undeserved.

Also, it meant we got stuck with more Alexander episodes.

10. Peter Preston

If you went to see Star Trek II: The Wrath of Khan when it came out, you were probably confused about why Scotty brought wounded midshipman Peter Preston to the bridge, and why he looked so stricken. But anyone who read the novelization of the movie by Vonda N. McIntyre, or watched the director's cut or the restored version that aired on ABC in 1985 already knows: Preston was Scotty's nephew.

When Scotty carries him in his arms to the bridge, we understand that his grief has driven him there, to this grand gesture that makes everyone realize just how much sacrifice had to be made.  In Sickbay, after Preston is gone, Scotty mourns for the loss of this idealistic, enthusiastic cadet who was his nephew, and died under his command. "He stayed at his post when the trainees ran," he tells iral Kirk.

Preston's death foreshadows the greater loss that Wrath of Khan gives us, but it's the first time we see Scotty get truly emotional; his grief-stricken voice says it all.

9. Tuvix

Tuvix is what happens on Star Trek Voyager when a transporter accident—a favorite Trek catalyst—combines Neelix and Tuvok into one being. He exhibits strikingly familiar qualities from both, retaining Tuvok's logic and brilliance, and combining it with Neelix's warmth and charisma.

When they determine they can fix the transporter, the decision of what to do next falls to Janeway. She has a responsibility to her officers, to do whatever she can to save them, doesn't she? But then what about this new person she's facing?  It's a murder that comes with a moral conundrum: is he a transporter accident, or an individual?

When she decides that her loyalty is to Tuvok and Neelix above all, she effectively sentences Tuvix to death. She can't dress it up: Tuvix will exist no more if she sends him back through the transporter, and he makes it extremely clear that he doesn't want to go. When the EMH won't violate his "do no harm" oath, Janeway is forced to ister the isotope to him herself. Judging by her face at the end, the memory of her act will haunt her for a long time.

8. The Salt Vampire

The enemy. A monster. But the last of its kind.

This was the first episode of Star Trek that ever aired, and it set up a monster-of-the-week template that fortunately never took hold. But like many a Star Trek monster, there was more to this one than met the eye.

This monster can transform itself into anyone, so for the past year or two, it's been playing the role of Nancy Crater, who just happens to be an old flame of McCoy's. It's been living with Nancy's husband, who knows what's going on and was hoping to hide its true identity. But the creature is desperate, and kills a couple of crew , then pretends to be one of them to get on the ship.

In the end, it attacks Kirk, and poor, already distraught McCoy has to kill it to save Kirk's life. Why they didn't just offer it salt and send it back home, we don't know. The poor thing just lies there on the floor, dead, its race gone ... and it could have coexisted peacefully if they'd only ed the salt.