Stratospheric Observatory For Infrared Astronomy The Stratospheric Observatory For Infrared Astronomy (SOFIA) will be a 2.5 meter, optical/infrared/sub-millimeter telescopemounted in a Boeing 747, to be used for many advanced astronomical observations performed at stratospheric altitudes. The Observatory will accommodate installation of different focal plane instruments, with in-flight accessibility, provided by investigators selected from the international science community. The Observatory objective is to have an operational lifetime in excess of 20 years. The SOFIA project is in the early full-scale stage. The start of deta