Dirilium

Dirilium, also known by its chemical symbol Drm-Δ, is a crystalline element which is used as the fuel source in the warp engines of starships in The Valkyrie due to the fact that it emits Delta radiation. Dirilium can be found in underground deposits on numerous different moons and planets in the galaxy, Humans discovering it themselves on Earth in the early 2060s, and the Arkadans are its main supplier within the Planetary Union due to the Arkadan homeplanet, Zalmara Prime, having the largest amounts of Dirilium deposits compared to other worlds and moons within the Union as a whole.