SOFIA will open a new era in astronomy: it will offer astronomers a unique platform, providing regular access to the entire MIR/FIR wavelength range between 5µm and 300 µm, part of which is otherwise inaccessible from the ground.

As demonstrated by the KAO (Kuiper Airborne Observatory), IRAS (Infrared Astronomical Satellite) and ISO (Infrared Space Observatory), infrared radiation characterizes a multitude of rich and varied physical processes, and reveals astronomical phenomena occurring in otherwise hidden regions of the cosmos. SOFIA will exploit and extend this scientific legacy by means of sensitive, high spectral and spatial resolution observations spanning the infrared domain. Topics to be addressed by SOFIA users include:

• Interstellar cloud physics and star formation in our galaxy.
• Proto-planetary disks and planet formation in nearby star systems.
• Origin and evolution of biogenic atoms, molecules, and solids.
• Composition and structure of planetary atmospheres and rings, and comets.
• Star formation, dynamics, and chemical content of other galaxies.
• The dynamic activity in the center of the Milky Way.
• Ultra-luminous IR Galaxies (ULIRGS) as a key component of the early universe.

Besides this contribution to science progress, SOFIA will be a major factor in the development of observational techniques, of new instrumentations and in the education of young scientists and teachers in the discipline of infrared astronomy.