The joint US and German SOFIA project to develop and operate a 2.5 meter infrared airborne telescope in a Boeing 747-SP is now in its second year. The Universities Space Research Association (USRA), teamed with Raytheon E-Systems and United Airlines, is developing and will operate SOFIA. The 2.5 meter telescope will be designed and built by a consortium of German companies led by MAN. Work on the aircraft and the primary minor has started. First science flights will begin in 2001 with 20% of the observing time assigned to German investigators. The observatory is expected to operate for over 20 years. The sensitivity, characteristics and science instrument complement are discussed.