NASA awarded the contract for the development of the aircraft, operation of the observatory and management of the American part of the project to the Universities Space Research Association (USRA) in 1996.

During 10-hour, overnight flights, it observed celestial magnetic fields, star-forming regions, comets, nebulae, and the Galactic Center.

The Boeing 747SP used to carry the telescope has been preserved and put on display at the Pima Air & Space Museum near Tucson, Arizona.

SOFIA was based on a Boeing 747SP, a factory shortened version of the wide-body aircraft that had been modified to include a large door in the aft fuselage that could be opened in flight to allow a 2.5 m (8.2 ft) diameter reflecting telescope access to the sky.

SOFIA's flight capability allowed it to rise above almost all of the water vapor in the Earth's atmosphere, which blocks some infrared wavelengths from reaching the ground.

[3] The optical system uses a Cassegrain reflector design with a parabolic primary mirror and a remotely configurable hyperbolic secondary.

A flat, tertiary, dichroic mirror was used to deflect the infrared part of the beam to the Nasmyth focus where it can be analyzed.

On April 17, 2012, two upgrades to HAWC were selected by NASA to increase the field of view with new transition edge sensor bolometer detector arrays and to add the capability of measuring the polarization of dust emission from celestial sources.

Tracking was achieved through a system of gyroscopes, high-speed cameras, and magnetic torque motors to compensate for motion, including vibrations from airflow and the aircraft engines.

Prior to landing, the compartment was flooded with nitrogen gas to prevent condensation of moisture on the chilled optics and instruments.

The telescope was German-made; the primary mirror was cast by Schott AG in Mainz, Germany with lightweight improvements, with grinding and polishing completed by the French company SAGEM-REOSC.

[15] On April 30, 1997, the Universities Space Research Association (USRA) purchased the aircraft from United for use as an airborne observatory.

To ensure successful modification, Raytheon purchased a section from another 747SP, registration number N141UA, which was being scrapped in early 1998 to use as a full-size mock-up.

Its 921st and last mission was over the North Pacific Ocean off the coast of California, taking off from Palmdale and returning there to land 7 hours and 57 minutes later at 04:41 PDT (11:41 UTC).

[23][24][25] The first use of an aircraft for performing infrared observations was in 1965 when Gerard P. Kuiper used NASA's Galileo Airborne Observatory to study Venus.

[28] The SOFIA telescope's primary mirror was 2.5 meters in diameter and was manufactured of Zerodur, a glass-ceramic composite produced by Schott AG that has almost zero thermal expansion.

REOSC, the optical department of the SAGEM Group in France, reduced the weight by milling honeycomb-shaped pockets out of the back.

After successful integration tests were made to check the system, the components were shipped to Waco, Texas on board an Airbus Beluga aircraft.

The first phase of loads and flight testing was used to check the aircraft characteristics with the external telescope cavity door closed.

SOFIA's telescope saw first light on May 26, 2010, returning images showing M82's core and heat from Jupiter's formation escaping through its cloud cover.

"The survey committee has significant concerns about SOFIA, given its high cost and modest scientific productivity," the report stated.

[41] In early 2017, its observations of 1 Ceres in the mid-infrared helped determine the large asteroid/dwarf planet was coated with a layer of asteroid dust from other bodies.

Sofia has been used also for Astrobiology missions, focusing amongst other goals on the observation of new planetary systems and the detection of complex molecules.

[43] In October 2020, astronomers reported detecting molecular water on the sunlit surface of the Moon by several independent spacecraft, including the Stratospheric Observatory for Infrared Astronomy (SOFIA).