Space Canopy and Greenbubbles
The Space Canopy is a smaller variant of the Canopy Plant, intended to create a breathable atmosphere around smaller planetoids and asteroids. Because such objects have minimal gravity, the Space Canopy cannot rely upon its own weight to counteract internal air pressure. For this reason the Space Canopy plant grows a network of strong, elastic biofibres within its outer surface to retain air without rupturing.
This variant was developed by Soft Cathedral refugees who had emigrated to the Zoeific Biopolity after the eighth Sagittarius Periphery War. The Space Canopy can be grown on carbonaceous asteroids, inner system dead comet cores or even on an airless moon that has volatiles enough in its crust. It can be directed to cover individual craters or an entire planetary body. Its growth process is roughly the same as that of the original Canopy Plant but the canopy consists of a tougher, more radiation resistant double-walled membrane. A reservoir of water between the walls of the membrane provides the majority of the interior's radiation protection.
The Greenbubble is a popular version of the Space Canopy that is used to envelop smaller bodies such as comets or minor asteroids. A double-walled canopy membrane grows out to approximately 100 metres in diameter and then pumps gases into the space between the walls. This begins to inflate the canopy into a great bubble. Customization of the interior space can begin at this point. As it continues to grow, the canopy envelope becomes double-walled yet again to create space for the water reservoir. This reservoir serves as the majority of the habitat's water supply, and also protects the contents against radiation and moderates temperature extremes. Strong vines in the interior space and over the canopy provide structural support and are conduits for the circulation of nutrients and bionano. Processed elements and chemical compounds are deposited within storage bladders. Curtain membranes subdivide the interior as desired. The final habitat is anywhere from 100 to 1000 metres in diameter, and can be further outfitted with non-biological components as well. Once full growth and customization are complete, the bubble separates from its root system. The established roots may then proceed to grow more bubbles for as long as the asteroid or cometary body can continue to supply feedstock. Depending on distance from the star it orbits and on the amount of power the inhabitants require, solar power collecting leaves can be grown or drytech solar energy collectors/generators may be attached to the basic Greenbubble. If waste heat disposal is necessary, the Greenbubble can grow organic radiators.
Greenbubbles can orbit their stars alone or in clusters. Clusters may be connected by direct attachment, or may be tied together by great umbilical vines and transit tubes.
The Space Canopy and Greenbubbles have been adapted for use as a tool for mining asteroids and comets as well as for habitation. For mining, the Space Canopy is directed to simply blanket the area being worked in order to prevent the escape of any volatiles while simplified Greenbubble envelopes are used to store the processed material until they are picked up.