Former Pan Am and United SOFIA Boeing 747SP retires to the Pima Air and Space Museum

SOFIA made this announcement:

SOFIA Boeing 747SP yesterday (December 13) flew for the last time to the Pima Air & Space Museum in Tucson. SOFIA took off for the last time from NASA’s Armstrong Flight Research Center in Palmdale, California. The pilots performed one last flyby of the area with a wing tilt to acknowledge everyone in the community who has supported and worked on SOFIA. The aircraft landed in Tucson, at the Davis-Monthan Air Force Base, where it will undergo final preparations before it is towed to the museum to eventually be on display to the public.

Composite image of SOFIA aircraft with Orion magnetic fields in the background and a swoosh depicting various mission patches. At the bottom are thumbnails of significant SOFIA science images.
With its observations, SOFIA’s traveled throughout the universe, and the aircraft traveled the world. SOFIA temporarily changed its home of operations 17 times after achieving “first light” to observe time-sensitive phenomena and parts of the sky not readily observable from its home base in Palmdale, California. SOFIA observed a wide variety of objects in our solar system, our galaxy, and beyond. Credit: NASA/SOFIA

SOFIA is a modified Boeing 747SP jet that was operated out of Armstrong. The SOFIA mission’s operations ended on Sept. 29, 2022 , but the team of incredible and diligent pilots and mechanics continued to support SOFIA as it prepared to go to its new home.

SOFIA is part of NASA’s legacy of airborne astronomy. Building on the successes of the Galileo I aboard a Learjet and the Kuiper Airborne Observatory, SOFIA was developed to provide the astrophysical community unprecedented access to the mid- and far-infrared wavelengths of light. This part of the electromagnetic spectrum is difficult to observe from Earth’s surface, because water in the atmosphere blocks mid- and far-infrared light from reaching the ground. SOFIA, flying above 99.9% of water in the atmosphere, could make observations of a wide variety of phenomena, from to cosmic magnetic fields.

In fact, SOFIA revolutionized the study of cosmic magnetic fields in astrophysics. Other observatories, like ESA’s (European Space Agency’s) Planck space observatory, could also detect polarized light and learn how these invisible forces affect galaxies. SOFIA, however, allowed scientists to make observations on much smaller scales. With the HAWC+ instrument, SOFIA probed dark rivers of material, called filaments, where stars start to form. They investigated the “bones” in galactic arms and caught the aftermath of galactic mergers. SOFIA also studied our galaxy and closest galactic companions, the Magellanic clouds.

SOFIA observed cosmic bubbles and how groups of massive stars trigger star formation or quench it, in some cases. SOFIA also could study molecules, making the first-ever detection of helium hydride, the first type of molecule that ever formed in the universe. SOFIA also turned its gaze on things much closer to home, like Venus’s atmosphere, comets, Pluto, and the Moon.

The SOFIA leadership team at NASA would like to share some thoughts:

“We want to express our gratitude to everyone, both our U.S. and German colleagues, who, over the years, developed, tested, and operated the observatory at Ames and Armstrong. It has been an incredible team effort to create and operate the world’s largest airborne observatory. None of this would have been possible without the community of scientists who have used and supported SOFIA over the years. We look forward to hearing everything the SOFIA scientific community learns as we go on. It is with heartfelt thanks that we at NASA say goodbye to SOFIA. We are sad to see you go but so happy to have worked with the SOFIA team.”

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

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.

Above Copyright Photo: United Airlines Boeing 747SP-21 N145UA (msn 21441) MIA (Bruce Drum). Image: 104847.

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.

The observatory’s flight envelope was established in a series of missions operating from the DAOF:

  • December 2009: First 100 percent open door flight
  • “First Light” flight achieved in May 2010. The first astronomical targets imaged by SOFIA were the planet Jupiter and the Messier 82 galaxy. The FORCAST instrument was used for these observations.
  • SOFIA made its first flight with the German REceiver for Astronomy at Terahertz Frequencies, or GREAT, in April 2011.
  • In September 2011, SOFIA made its first transatlantic deployment to Germany.
  • SOFIA deployed to Christchurch, New Zealand, for observations of the southern sky in July 2013.
  • SOFIA studied the comet ISON in November 2013.

Aircraft Modification

The Boeing 747SP that is SOFIA underwent extensive modifications by L-3 Integrated Systems in Waco, Texas, from 1998 to 2007. L-3 Integrated Systems was responsible for the aircraft’s modifications including design engineering, airframe structual modifications, telescope design integration, and flight test activities.

The modification from a commercial jetliner into an airborne observatory included:

  • retrofitting the aircraft’s structual support system
  • creating a cavity in the aircraft to house the telescope
  • installing all required support systems
  • retrofitting the interior to provide working areas for scientist and educators.

Installing a 2.7-meter telescope in an airplane had never been done before and the modifications necessary posed many complex and challenging problems for the engineers. One of the most challenging problems is keeping the aircraft steady while flying with a 20-ton telescope in a huge cavity in the rear of the plane that is opened to the sky.

Top Copyright Photo: NASA Boeing 747SP-21 N747NA (msn 21441) (SOFIA) CGN (Rainer Bexten). Image: 954602.

NASA aircraft slide show: