Dowsing Engine for Space Stations

[Erev]

Take one specially designed asteroid magnet that pulls in hot space rocks. Do your Oshan-style dowsing and geothermal work. Have a maximum amount of heat/energy in each asteroid. Release the rock when it is petering out and bring in a new one to start again.

This opens up a new, more active engine option. Perhaps allow it to be worked alongside the miners - two birds with one stone.