Idris Janek was the captain of the USCSS Prometheus during the ship's mission to LV-223. He died after he, Chance, and Ravel flew the Prometheus into the Engineer's ship in a successful attempt to stop it delivering the black liquid to Earth.
"No matter what happens down there, I can't bring none of that shit back home with us. Can't let it happen. And I'll do whatever I have to to see that it doesn't."