While they are used on many colonies, due to the extremely small investment in infrastructure required, Sialhaith (Lumenna III) is the world on which the modern airship has reached its apotheosis. In Sialhaith’s hot, thick atmosphere – the planetary ecopoesis program was bought out and effectively terminated in its 150^th year by the aerostat consortium – a standard oxygen-breather atmosphere serves as a potent lifting gas, the factor which enabled its sky cities to exist in the first place.

This same factor makes Sialhain an airship designer’s dream.

Picture, if you will, a broad, flattened ellipsoid envelope of tough, lightweight, clear aerogel – perhaps a full mile in length. It supports a traditional gondola, certainly, holding its reactors, ducted magnetoaerodynamic engines, and pylons for shuttle aeronefs hanging below, but unlike conventional designs, the gondola doesn’t represent the habitable space of the airship. The lifting gas, after all, is entirely breathable. Instead, look down upon the envelope, and in place of ballonets, ballast pumps, and other support machinery within, see instead a single, vast, open volume, in which the designer has scattered a small town’s buildings over a lightly wooded park. That’s the simplest possible Sialhain airship.

How many Sialhain designers do you think were content to build the simplest possible airship?