The Wheel

The Wheel is a marvel of technology, a massive, spinning ringworld constructed around the dwarf star Prycil A at a distance of about 0.1 AU, with a total habitable surface area equaling nearly 100 billion square miles (or about 500 Earths). As such, its surface area could easily support over a trillion Terrans, though as all of humanity numbers only around 80 billion. At current growth rates, The Wheel could potentially accommodate all of humanity for centuries to come.
Currently 12 billion inhabitants live on the inside surface of The Wheel. The gravity created by its spin, and its size, make The Wheel large enough to maintain an atmosphere, making the Wheel more like an enormous planet than a space station.
Its inhabitants have no need for Dome Colonies, bubbles or spacesuits. Land masses and oceans have been entirely designed to maximize beauty and efficiency, making The Wheel a prime destination for humans of all stripes. As the Wheel spins, the sun disappears behind shadow squares, positioned in a stationary orbit around Prycil A between the Wheel and Prycil A itself, creating the illusion of days and nights as you might have on a planet. The back side of these squares is covered in solar collectors, allowing them to generate and transmit energy all day and night - in fact, more than is required to support all Terrans who live on The Wheel.
The Wheel is the current seat of Terran power, including housing headquarters of nearly every major corporation. Corporate headquarters on the Wheel have been terraformed to that corporation's specifications, and tours are available to nearly all of them daily for a small admission cost. Among these: Terran Systems, Hive Energy, Novak Cantor Progenature, Inc., and the Wheel Banking Corporation (WBC).

Purpose / Function

The Wheel was constructed to allow the contributing corps unfettered access to the resources of the Triptych.
It was also a convenient way to dispose of the cache of Quantum weapons that remained on Earth post World War 4 and were otherwise determined to be too dangerous to detonate.
The construction of the Wheel also led to the invention of the Sparker, which was forcibly spliced into millions of members of the construction crew.

Architecture

All the inhabitants live on the inside surface of The Wheel, and it is large enough to maintain a true atmosphere - there are no need for bubbles or spacesuits on the Wheel, making it prime destination for humans of all stripes. 1,000 mile walls are built on both sides to keep in the atmosphere. As the Wheel rotates, the sun disappears behind the back end of the Wheel itself, creating the illusion of days and nights as you might have on a planet.

History

Humanity’s first jump point linked Sol to the Cygni system, which was home to our first extra-solar colony. Our second Jump Point, built and operated by Terran Systems, wound up being much more lucrative.
From the moment humanity arrived at Palladia, the crew realized the uniqueness of the nearby systems. For starters, three different star systems - Prycil, Palladia, and Magellan - were in close proximity. Travel between them takes less than a year even without the need for jump points. Secondly, all three stars have multiple resource-rich planets, though nearly all were in need of some sort of terraforming. Lastly, a large number of asteroid belts and comets weave in and between these stars.
Quickly recognized to be the jewel of the ever-expanding Terran presence, all corps become interested in their piece of the mining, gas-harvesting, and production potential in the systems. Knowing travel back and forth would become profitable much more quickly than in Cygni, every major corp began sending their own scouts to build Jump Points to bypass the levies imposed by the others. But with only one habitable planet, and terraforming taking up to 100 years to complete (before modern technology got it down to its current 30-40 years), a rare multi-corp collaboration, The Wheel, is devised. Like a space station but far larger, and capable of housing billions of people, a spinning ringworld is proposed, within the Goldilocks Zone of Prycil, perfectly suited to nurture Terran life.
The Wheel is built in part by pulling together using nanites to harvest the raw materials from the asteroid belts as well as several gas giants in the system. Additionally, humans utilize a new technology, The Little Bang, to generate and collect matter more rapidly, and set their nanites to work on constructing the proper elements, at which point Terran, Sparker, and robotic contractors assemble those elements into The Wheel. Though it takes 50 years and costs tens of trillions of dollars to complete, The Wheel ends up being one of humanity’s greatest accomplishments.
Its staggering material cost is subsidized with real estate value - real estate on Earth, and on most newly-terraformed planets having long since been at a premium. Organizations contributing time, money and resources to the Wheel's assembly stake ownership in the newly-created land masses, which are built from scratch and to custom specifications: everything from vast plains and beautiful mountainside vistas to stretches of pristine beach tens of thousands of miles long. The concepts and designs behind The Wheel become an inspiration to all of humanity.
After two generations of work, all major governments and corporations complete construction on The Wheel, and it instantly becomes both a symbol of unity and a way to house the rapidly overpopulating masses of humanity. Billions are drawn to it through a number of Jump Points now in place, though at first, real estate is marked up exorbitantly to cover investment costs, and only mega-corporations and extremely wealthy individuals stake early claims to the best swaths of land.
Most importantly, all of the major corps move their headquarters to the Wheel, so that they may better harvest and populate these new systems, which together are dubbed The Triptych. All potentially habitable planets in the system are colonized - 11 in total - terraforming begins on all planets and most of the moons, and the Triptych remains the core of Terran production until present day. The Wheel also houses the headquarters of most major corporations including Terran Systems and the Wheel Banking Corporation (WBC).
Lured by the marketing put behind the Wheel, much of it pushed through Terran Systems media, a vast majority of humans finally leave the Earth for new bastions of humanity such as The Wheel and the Triptych.

Type

Orbital, Halo / Ringworld