Percolator

A large (one million tons and up) robotic spacecraft used to refuel gigantic ships or fuel tanks from a gas giant. The "percolator" is sent into the atmosphere to force a hydrogen slurry above the atmosphere. Thus a ship could use fuel scoops without entering the atmosphere. It would take days or even weeks to refuel, since the "slurry" is a highly local phenomenon.

On the other hand, a percolator's activity is easy to spot from a great distance, since the slurry acts as a signal, reflecting energy with high efficiency.

Technological Requirements

The percolator is a TL18 structure.

The practical robotics and AI of the percolator is available at TL16. Scrambler technology, used here to agitate the atmospheres of exotic worlds, is a TL17 technology. Finally, the holographic equipment used for calibration and maintenance of the hydrogen column is available at TL18.

Early percolators are available at TL17.

Obsolescence

The percolator's lifespan is relatively short: at TL19, elemental matter transporters are available, and hydrogen can be transported directly off the atmosphere via a teleporting skimmer.