SOFIA, the airborne telescope that backed up New Horizons in studying Pluto, will go on flights to observe our universe until the end of 2020. NASA and the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt or DLR) have extended their joint project for four more years. SOFIA is a 17-ton infrared telescope with an 8.9-foot-diameter primary mirror fitted into a Boeing 747SP wide-body plane. A hatch on the aircraft slides open so the telescope can get a view of the sky. And since it operates at altitudes of about 41,000 feet, it can make its observations above most of the water vapor in the Earth's atmosphere, which blocks some infrared waves.