The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint project of NASA and the German Aerospace Center (DLR). Universities Space Research Association (USRA) was awarded the prime contract by NASA in 1996 for development and operation of the observatory.

SOFIA is a Boeing 747SP airliner modified to carry a 2.5 meter diameter reflecting telescope for infrared astronomy observations at altitudes of about 41,000 feet (~12 km) in the stratosphere. Its flight capability will allow it to rise above almost all of the water vapor in the Earth's atmosphere (allowing observations at some infrared wavelengths which are blocked by the atmosphere before reaching ground-based facilities), as well as travel to almost any point on the earth's surface for observations. The telescope looks out of a large door in the side of the fuselage near the airplane's tail, and will initially carry nine instruments for infrared astronomy in wavelengths from 0.35–655 micrometres.

The primary science objectives of SOFIA are to study the composition of planetary atmospheres and surfaces; to investigate the structure, evolution and composition of comets; to determine the physics and chemistry of the interstellar medium; and to explore the formation of stars and other stellar objects.

Once ready for use, it is hoped that observing flights will be flown 3 or 4 nights a week for the next 20 years. SOFIA will be based at NASA's Ames Research Center at Moffett Field, California (near San Jose, CA).

Current Status

19 August 2006 SOFIA completed aircraft system tests including engine and taxi tests at Waco Airport.^[1] October 2006 SOFIA came out the hanger with a new paint job. The first flight is slated to be only a few months away.^[2]

The Telescope

The telescope has a diameter of 2.7 meter, however the effective aperture is only 2.5 meter. DLR is responsible for the entire telescope assembly, the manufacturing of the telescope was subcontracted to the Germany industry.

For each mission one changeable science instruments will be attached to the telescope. Two groups of general purpose instruments are available. In addition an investigator can also design and build a special purpose instrument.

Project Development

SOFIA completed its first ground-based "on-sky" test on 18–19 August 2004 by taking a picture of the star Polaris.

In February 2006 NASA placed the project "under review" and suspended funding. On the 15th of June 2006 SOFIA passed the review^[3].