Terraformers

Terraformers were originally engines which powered Class 3 transports.
Smaller and cheaper terraformers were developed as part of a colonization initiative. These terraformers were designed to begin altering the atmosphere at a much slower rate, until larger terraformers could be built to replace them. This version of terraformer was expected to stop working after 1,000 years, but a remarkable number of them continued to function. Through the millennia, the terraformers have gradually transformed many of the uncharted planets.

The largest known working terraformer is in Red Sky Holt. Due to the significant impact it has on a planet, cities are built around them and they become a planetary focal point. Red Sky is believed to have the only terraformer on the planet.

These were created by the ancients. Capable of utterly changing environments on a planetary scale. However, they were built with a design flaw. The architect of the terraformer was unable to automate the recalibration every 1,000 years. So every 1,000 years, the terraformers shut down for a period of 1 solar year. For thousands of years, the Terran Order stood by to *literally* hit a button to postpone the update for another 1,000 years.
Once the order was dissolved (through political intrigue), a thousand years came and went. As terraformers began shutting down, atmospheres on whole planets were stripped.
On some planets, once the plant life took root and the atmosphere established, the terraformers became obsolete. However, the outer planets still depend entirely on the terraformers to maintain liveable conditions.
Arcos, the esteemed artist/inventor, had hacked into the system almost by accident and repaired the fault on the Red Sky's terraformers. It's still a mystery as to whether or not he realizes he saved the outer planet from complete destruction.