NASA’s SOFIA flying telescope, retired in September after 12 years of observing the cosmos from the stratosphere in a modified Boeing 747, is moving to its permanent home at the Pima Air & Space Museum in Tucson, Arizona.
The Stratospheric Observatory for Infrared Astronomy (SOFIA) made its final flight on December 13, departing from its old headquarters at NASA’s Armstrong Flight Research Center at Palmdale Regional Airport in California. After taking off, the aircraft’s pilots conducted one last low-altitude flyby of the area “with a wing tilt to acknowledge everyone in the community who has supported and worked on SOFIA,” NASA officials wrote in a blog post. SOFIA landed at the Davis-Monthan Air Force Base in Tucson, where it is undergoing final preparations before going on display at the museum.
Pima is one of the world’s largest aerospace museums. It is home to several other retired NASA aircraft, such as the Super Guppy that was used to transport Saturn V rocket parts during the Apollo era. The museum also houses a Boeing KC-135 Stratotanker nicknamed the “Weightless Wonder V,” which the agency used to simulate weightlessness by flying in parabolic arcs for astronaut training and science experiments.
SOFIA, a joint project between NASA and the German Aerospace Center (DLR), was an astronomy platform like no other. The airborne observatory consisted of a 2.5-meter (8.2 feet) reflecting telescope built into the fuselage of a Boeing 747SP widebody airliner, with a large door in the aft fuselage that could roll open during flight to provide a view of the sky.
Designed to observe the universe in infrared light, the observatory regularly conducted 10-hour-long, overnight flights at an altitude of about 41,000 feet (12 km). At this altitude, SOFIA flew above 99.9 percent of the water vapor in Earth’s atmosphere. Atmospheric moisture can scatter infrared light, making it difficult to conduct infrared observations from the ground.
Among its most notable scientific contributions were the discovery of water on the sunlit surface of the moon, the detection of the first molecule to form in the universe after the Big Bang, and the mapping of magnetic fields in galaxies across the universe.
SOFIA conducted its first test flight in 2009 and began making astronomical observations in 2010. It achieved full operational capability in 2014 and conducted more than 100 flights per year during its subsequent five-year prime mission, which was extended for another three years in 2019. The following year, the National Academies’ 2020 decadal survey on astronomy and astrophysics determined that SOFIA’s science gains no longer justified its operating costs, so NASA and DLR began making end-of-life plans for the flying observatory.