SOFIA is attached to the airframe aft of the wing on a heavily modified Boeing 747 SP jet. This aircraft was utilized in its original configuration for commercial operations by Pan Am and later United Airlines until it was purchased by NASA in 1997.
Modifications have afforded the 17-ton, 2.7-meter reflecting infrared-capable telescope superior views, increasing its ability to scan more distant regions of space. Relying on SOFIA is scientifically more advantageous than utilizing ground-based telescopes. Though primarily designed for infrared research, SOFIA can also be used to study visible light from outer space.
Scientists expect to conduct observations at heights of more than 39,000 feet. At such heights, the earth's rarified atmosphere is devoid of 99% of its water vapor. This does not hinder observations, as is the case with ground-based telescopes. SOFIA is designed to operate in the stratosphere while the aircraft cruises at speeds of around 500 miles per hour. Despite SOFIA's weight, it is designed for stable use even if flight turbulence should occur.
SOFIA took off on its maiden flight from Waco, Texas, in April 2007. It will be further developed at the Dryden Flight Research Center, which is based in the Mojave Desert in Southern California. It is expected to reach full operational capacity for conducting astronomical missions by 2010. NASA has stated that it intends to develop SOFIA as an exceptional airborne observatory that will complement the Hubble, Spitzer, Herschel, and James Webb telescopes.
SOFIA is designed to support existing scientific research conducted via ground-based telescopes. Engineers have designed nine observation instruments for SOFIA. Seven of these instruments were designed in the United States, while two were designed in Germany. With their help, scientists hope to make sophisticated observations of the cosmos by viewing "dark" clouds, the births of new stars, black holes, and galaxies.
SOFIA is expected to produce images that are three times better in quality than those of the Kuiper Airborne Observatory. A total of $3.2 billion in funding is expected to be spent over SOFIA's operational lifespan of around 20 years.
SOFIA's capability to return to Earth after missions will enable further research on future scientific instruments for space exploration, opening doors for advanced research and development and engineering projects.
