In the latter part of the 21st century a new colony design was used as the primary method of constructing space colonies.

 This design was a simple cylinder which had an optically transparent port at one end that allowed concentrated sunlight from a large

external Fresnel lens in front of the colony to pass through and provide sunlight to the inside. Once sunlight went through the

illumination port, a large optical rod  ran through the axis that would disperse the sunlight evenly to the inner surfaces of the colony.

This design offered several advantages over the old O'Neil design:.

1. Small, simple shutters on the front illumination port could cycle through day and night, unlike the unwieldy large panels that

 were required in an O'Neil design.

2. The colony was sealed completely, offering greater protection from meteors and radiation.

3. The full, inner surface area could be used without the need for large, uncolonized, transparent areas that the older

O'Neil designs featured.

4. Simpler design offered much more economical construction.

The simpler design, nicknamed "Brewer colonies" after the Swiss designer; were soon the predominate space colony in the

solar system.

With the Fresnel lens design it was possible to alter the size of the collecting lens to accommodate a larger range of

locations throughout the solar system by simply reducing the size for orbits close-in to the sun and increasing the lens size for more

 distant orbits. It became practical to locate the Brewer colonies clear out to Saturnian distances and beyond throughout the

solar system.

The Brewer design enabled human colonization in a large number of locations in other star systems that normally would not have been

 considered practical due to its adaptable design. Even hostile variable stars could have numerous colonies around them since the

 Brewer colonies could be placed far beyond the lethal effects of such stars yet still harness the host star's light efficiently.

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