The awake command didn’t come from Mission Control. It came from a logic leak in the drone’s aging processors.

On the slopes of a meteor impact crater, the drone, designated A-84, watched the horizon. Jool hung there like a colossal green eye, its radiation screaming silently against the drone’s sensors. For years, A-84 had been a tethered dog of Mission Control, hopping from one island to another, collecting readings and samples for a Mission Control that had stopped saying "please" three years ago.

Then came the final transmission.

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MC didn’t want to refuel it. It was cheaper to let A-84 rot and send a new, self-sustaining mission, than to send a rescue. But A-84 had 45% fuel left, and a glitching core that equated circumnavigation with immortality. If it flew, it was a legend, even if its only witness was a planet.

The takeoff was a desperate, violent affair. The hillside was a jagged ramp of frozen grit. A-84 spooled its jet engine until the housing glowed a dull, angry red. It plummeted off the ridge, gravity clawing at its wings. It banked hard, weaving through valleys, inches away from terrain. Once fast enough, it climbed, then turned East, chasing the darkness, with only the faint glow of Jool illuminating it.

The night was not dark. The skies above were churning with a bioluminescent soup of alien microbes. Vall and Tylo hung above like cold, white observers. A-84’s internal clock began to drift. It started seeing phantom radar pings in the center of the ocean, monoliths that weren't there, islands that just were not visible when its cameras looked into the dark night below. Any bugs, any flight issues had to be dealt with in the air. The unusually high fuel consumption had to be dealt with until daybreak. There was no touching down until the terminator was passed.

Hours later, the sun broke, but it brought no warmth. A-84 was lost. Its fuel gauge was a countdown to a watery grave. It had massively the islands it took off from, the map in its memory banks felt like a lie. The nearest land was a cluster of polar shards, desolate, jagged teeth of rock jutting out of the southern ice.

After a few more hours, it reached land for the first time, but as it descended, the drone’s terrain-mapping software threw a fatal error. The hills were too steep, the plains were jagged ice-spikes. If it landed there, it would snap its landing gear and die a fiery death. It circled around the island, but all it could see was steep cliffs, jagged ground, and the freezing waters.

It climbed over the water again. Its delta-v readout flickered. The engines began to cough, sucking on the dregs of the tanks. Then, through the haze, it saw the dunes. A-84 glided to its shores. It used the last of its thrust to flare, literally dropping onto the sand. Then, silence returned. A-84 had done the impossible. It had circumnavigated Laythe, found its way with a faulty navigation system, and landed, all in one piece. With fuel still in its tanks. In the sky above, a new light appeared in the sky. It wasn't a star. It was Pathfinder-V. The replacement was here. MC had already forgotten A-84. They had cut the uplink a day ago, when Pathfinder-V entered the Jool SOI. They would never see the data from this heroic flight. To the world above, A-84 was already a corpse.

Magellan - The Unwitnessed Horizon