The SOFIA aircraft is a Boeing 747SP with a distinguished history. It was originally acquired by Pan American World Airways and was delivered in May 1977. The “SP” designates that this is a special performance, short-body version of the 747, designed for longer flights than the Boeing 747 Classics (747-100, -200, and -300 series jetliners).
Although Pan Am typically named its aircraft after famous clipper ships, they gave this aircraft a special name — the Clipper Lindbergh — in honor of the famous aviator Charles Lindbergh. Lindbergh’s widow, Anne Morrow Lindbergh, personally christened the aircraft and officially placed it into service on May 6, 1977 — the 50th anniversary of his history-making first solo flight from New York to Paris in 1927.
In February 1986, United Airlines purchased the plane. United removed it from active service in December 1995, and it was purchased by NASA in 1997. The aircraft was substantially modified for its new role as a flying astronomical observatory by L-3 Integrated Systems of Waco, Texas. To ensure proper modification, a dismantled section from another 747SP was used as a full-size mock-up.
On April 26, 2007, SOFIA made its first post-modification flight in the skies over Waco, Texas. It was subsequently flown to Dryden Flight Research Center at Edwards Air Force Base, Calif., for continued flight testing, and was rededicated on May 21, 2007, by Erik Lindbergh (Charles Lindbergh’s grandson).
On January 14, 2007, at the end of its closed-door flight testing, SOFIA briefly visited Ames Research Center before continuing on to its permanent flight operations home at the new AFRC-operated Dryden Aircraft Operations Facility (DAOF) in Palmdale, California.
Model: Boeing 747SP (Special Performance)
Number built: 45; still in service: 14
Manufacturer’s serial number: 21441
Line number: 306
Based: NASA Dryden Aircraft Operations Facility (Site 9), Palmdale, Calif.
Staffing: Flight Crew: 3; Mission Crew: 2–6; Observers/Educators: 5–15
Fuselage Length: 177 feet (53.9 meters)
Standard 747-400: 232 feet (70.5 meters)
Wingspan: 196 feet (59.7 meters)
Powerplants: 4 x Pratt & Whitney JT9D-7J turbofan engines (50,000 lbf thrust each)
Service Ceiling: 45,000 feet (13.7 km) — above 99.8 percent of the Earth’s atmospheric water vapor
Airspeed at 41,000 feet: 450 knots (Mach 0.8 or 520 mph)
Range: 6,625 nautical miles
Mission Duration: 7 to 9 hours (standard); 12.2 hours (maximum)
SOFIA empty weight (zero fuel): 378,000 pounds (189 short tons or 171,458 kg)
SOFIA Maximum Take Off Weight: 696,000 pounds (348 short tons or 315,700 kg)
Maximum Fuel Load: 300,000 pounds (44,776 U.S. gallons)
Fuel Usage: 150,000 to 250,000 pounds (standard duration mission)
Cavity Door weight: 3,150 pounds (1,430 kg)
Above information taken from: https://www.sofia.usra.edu/Sofia/aircraft/sofia_ac.htm