Fuel Sifter
From librae wiki
Fuel Sifter is an Asset that produces Fuel by sifting through upper layers of local planetoids. Efficiency depends on the historic presence of a magnetic field which would deflect the incoming He-3 over millions of years, preventing its accumulation.
Construction cost: 50 + 10 * bio_quality_diff + 10 * atmosphere_quality_diff + 10 * effective_cosmic_ray_intensity + 50 * (1 - fuel_availability)