Nature: In 1996, NASA and its German counterpart the DLR agreed to build the Stratospheric Observatory for Infrared Astronomy, an IR telescope mounted in a converted Boeing 747. Fourteen years later on 26 May, SOFIA's 2.7-m telescope, which peers from a large door in the airplane's fuselage, saw its first light. Nature's Eric Hand examines the long-delayed mission's likely scientific payoff.
