As these get smaller and smaller, we get closer and closer to a dog pod grid:
Aerostat meant anything that hung in the air. This was an easy trick to pull off
nowadays. Nanotech materials were stronger. Computers were infinitesimal. Power
supplies were much more potent. It was almost difficult not to build things
that were lighter than air. . . .
Given that it was so easy to make things that would float in air, it was not
much of a stretch to add an air turbine. This was nothing more than a small
propeller, or series of them, mounted in a tubular foramen wrought through
the body of the aerostat, drawing in air at one end and forcing it out the other
to generate thrust. A device built with several thrusters pointed along
different axes could remain in one position, or indeed navigate through space.
Each aerostat in the dog pod grid was a mirror-surfaced, aerodynamic teardrop
just wide enough, at its widest part, to have contained a pingpong ball. These
pods were programmed to hang in space in a hexagonal grid pattern, about ten
centimeters apart near the ground (close enough to stop a dog but not a cat,
hence "dog pods") and spaced wider as they got higher. In this fashion a hemi-
spherical dome was limned around the sacrosanct airspace of the New Atlantis
Clave. When wind gusted, the pods all swung into it like weathervanes, and the
grid deformed for a bit as the pods were shoved around; but all of them even-
tually worked their way back into place, swimming upstream like minnows, pro-
pelling the air turbines. The 'bines made a thin hissing noise, like a razor
blade cutting air, that, when multiplied by the number of pods within earshot,
engendered a not altogether cheerful ambience. Enough wrestling with the wind,
and a pod's battery would run down. Then it would swim over and nuzzle its
neighbor. The two would mate in midair, like dragonflies, and the weaker would
take power from the stronger. The system included larger aerostats called nurse
drones that would cruise around dumping large amounts of power into randomly
selected pods all over the grid, which would then distribute it to their neigh-
bors. If a pod thought it was having mechanical trouble, it would send out a
message, and a fresh pod would fly out from the Royal Security installation be-
neath Source Victoria and relieve it so that it could fly home to be decompiled.
--Neal Stephenson, The Diamond Age
