a to z: generation ships / by Katherine Hajer

Earth Colony Ship 8 didn't completely shut down for years after the arrival on Gaia. It served as a machine shop, factory, laboratory, and community media hub long after the colonists had settled a village around it.

Most notably, it served as their communications array until they could mine enough ore and gather enough resources to build a planet-side one.

After Captain Sorensen's discovery of the mysterious text-based message, they'd switched to reception only for interstellar-strength messages. There had been some initial worry over "them” finding the colony. Eventually that waned, to be replaced by a new worry: that they were the only ship that had arrived safely.

There were a few different lines of thought about the warning message. There was a conspiracy theory that malevolent forces had sent the message, but this was largely dismissed. Many simply took it at its word. Some worried that “they” had found more than one ship.

Thirty-five years after arrival, the interstellar comm array was one of the few things left on the ship still being put to practical use. Several of the decks had been converted into a museum. The bridge wasn't checked at all unless an alarm went off.

And then the message reception alarm did go off, twice, within a few weeks.

Unlike the earlier message, these had both audio and text attached to them. The first was from Ship 3. They'd arrived, but their target planet was swampy, overheated, and had far too much methane in the atmosphere to allow human life to thrive. The message ended with a note saying the crew intended to try to terraform a nearby moon with a thin atmosphere, but they didn't sound optimistic.

The second message came from Ship 9, and was nearly unintelligible, because the man leaving it was sobbing. Somehow the ship’s sensors had missed a piece of debris coming at it. The hull was breached, and enough of the main engineering area destroyed that the ship was disabled. Life support and the comm array were the only two systems permitted power;  when they ran out of energy, everyone on board the ship would die.

Had died. It had taken years for the message to reach Gaia.

After much debate, a short acknowledgment message was sent to Ship 3, deliberately worded so it could be plausibly misconstrued as an automatic message, as opposed to proof of life. No response ever came back.

The Gaians slowly realised that while they may not be alone in the universe, they were probably the only living humans.