The Nutrient gas system was a system in Kilrathi space ships that pumped dense nutrient atmosphere around a Kilrathi pilot or onboard their ships. The nutrient gas was a synthetic manufactured gas based on the original natural gases of Kilrah (or at least related to the environmentally damaged atmosphere on the planet). After the destruction of Kilrah's environments after many years of war, nutrient gases pumped into the atmosphere often made up the clouds on the planet. Kilrathi civilization abutted a range of great mesas crowned by swirling clouds of nutrient gas.