A large mirror in orbit, known as an Orbital Solar Energy Transfer Satellite (also called an Orbital Mirror, Mirror Station, or Solar Mirror), served to concentrate heat and sunlight from Coruscant's small star onto the planet's far northern and southern areas. This increased the temperature by a small amount, expanding the habitable areas of the ecumenopolis. The Galactic Republic, the Galactic Empire, and the New Republic all made use of these space stations.
Even though the stations were quite large, the majority of their size was due to the mirror, which enclosed a compact guidance station where the OSETS's keeper was based. The mirror itself was a vast sheet of reflective material, only a fraction of a millimeter in thickness. It was connected to many cables, which in turn were linked to rockets for attitude control. The station's staff could operate the mirrors from within, depending on how much autonomy they had, in the event of a problem.
The guidance station's interior was extremely dim and confined. Exposed pipes and wires covered the ceilings and walls. A single chair was positioned in the center of an observation bubble in stations managed by a single caretaker, providing a view of the planet below. The caretaker's responsibility was to monitor the solar trajectory and make adjustments if the station's nearly obsolete computers failed to complete their intended purpose.
The stations were operated by small crews or solitary caretakers working in shifts, depending on their size. These individuals were expected to be ready for infrequent emergencies. The caretakers' task, commonly known as "riding the mirrors," was regarded as one of the least desirable jobs available.
During the Imperial era, the stations were staffed by lower-ranking Imperial Navy personnel and stormtroopers who were being disciplined for disobedience. The position remained equally undesirable after the Empire was replaced by the New Republic. While the stations were still run by low-ranking personnel, they were also staffed by well-compensated independent contractors who could be called upon if the officers were needed elsewhere. Despite the compensation, the station's environment frequently had a detrimental effect on the mental health of those assigned there. The few amenities the stations had were prone to failure due to bureaucracy and a lack of funding.
However, some people, most notably Virar Needa, saw riding the mirror as a respectable responsibility. He created a self-deceptive bubble that enabled him to carry out his mundane duties with the highest level of effectiveness and passion. For instance, Needa made it his pastime to keep traffic observation logs, a task that the majority of OSETS officers would avoid.
In 7 ABY, when the New Republic tried to reclaim Coruscant from the Imperials, Rogue Squadron seized control of the computer center on Coruscant that managed the OSETS satellites. They then took command of OSETS 2711, which was being manned by Needa and a few other comrades. The Rebels repositioned the satellite to heat a sizable water reservoir, which resulted in a violent thunderstorm that destroyed the planet's shields. The New Republic Defense Fleet entered the Coruscant system shortly after and started their liberation of the throne world.
OSETS 2711 was also used to burn a hole in one of the Imperial Golan III platforms, which helped to lower casualties on both sides. The battle was survived by OSETS 2711.
The New Republic would keep using the stations, though it had let the caretakers' situation get worse. In 23 ABY, Jedi trainees Jaina Solo, Lowbacca, and a caretaker by the name of Peckhum used a solar mirror to destroy the Shadow Academy's cloaking device, exposing it to the New Republic fleet. The station, however, activated its hyperdrive and fled into hyperspace before the fleet could inflict any serious damage.
The extragalactic invaders, the Yuuzhan Vong, destroyed the OSETs during their conquest of Coruscant. In some instances, they were used to demolish buildings by crashing them into the surface.