When Survery Flotilla Delta-Nine-One of the old United Nations Explorer Corp first entered the Luminaire system in 98 AE, it was clear that the planet Luminaire would be the only one capable of supporting human life without massive terraforming. Lacking the necessary tools to locate plausible hyperspace jump points meant that the flotilla had to return to colonised space the same way it arrived - sublight light travel.
The onset of the African Civil War in 100 AE paused further exploration fleets, and it was only at the war's conclusion in 124 AE did funding resumed for exploring and colonising. In 126 AE, the Luminaire Colonisation Project was initiated as a joint-venture between various member states of the Western Confederation. In 128 AE, a small pre-colonisation squadron was sent ahead to Luminaire, to prepare for the main arrival of the actual colony ship. In 130 AE, the main colony ship launched.
A slight miscalculation by the launch team overestimated the distance between Terra and Luminaire, and the duration of the cryogenic sleep was tuned with the wrong distance in mind. By the time the inhabitants of the pre-colonisation ships had been woken up by collision alarms in 184 AE, two of the five ships in the squadrons were already destroyed due to the asteroid field in the system. They were supposed to be awaken outside the star system, instead, the miscalculation had them sleeping well after that.
The purpose of the pre-colonisation ships were to set up a landing zone with rudimentary colonisation equipment already set up so that the main colony ship would have a relatively easier time on arrival. Unfortunately, both ships that were destroyed contained valuable supplies and food rations for the squadron, and it appeared unlikely that the survivors of the three ships could survive on remaining rations for the two years it would take for the colony ship to arrive, and pre-colonisation ships of that time were designed for one-way trips in mind.
The three ships - Endeavor
, Martin J. Cohen
remained in orbit for several days, scanning for a suitable landing site. It was then decided that the available resources left will be utilised to construct four towers on the designated landing zone that coincided with the compass points. The automated towers would emit the transmission codes to the colony ship to force it to wake the deep-sleeping colonists up when the ship entered range, as presumably the same mistaken calculation would have been used by the ship.
Secondly, the towers would act as homing beacons for the colony ship to identify as its landing zone, and failing that, the towers themselves would be emitting light visible from even orbit. When construction was completed, the surviving crew members of the squadron went back into deep-sleep onboard their ships, their food rations almost depleted, hoping that the cryogenic systems will hold out long enough for the main colony ship to arrive and rescue them.
When the main colony ship neared the edge of the system two years later, sensors of the Freedom
picked it up, and following the preprogrammed script, it activated the towers. As planned, the colony ship forced its colonist awake, and it was able to enter the system without any mishaps. The automated transmittors failed while they were entering planetary orbit, but the light from the beacons were able to guide the ship to the landing site safely.
Amazingly, all the crew members of the three ships survived the deep sleep, and were revered as heroes when revived. The four towers came to be known as the Crown of Suns, and are now a permanent presence in the city skyline. Likewise, the name chosen for the first city established on Luminaire is 'City of Lights', after the shining lights from the towers.
Nowadays, they stand about a kilometer tall each, and the lights are turned on during the night, bathing the city in a soft glow. Much like its original purpose, they continue to be visible from space.
edit: credits to planetes
coming up with a better name for the towers.