In 1996, scientists initiated an ambitious plan to modify an airplane so it could carry a massive telescope through the sky.
The project, known as the Stratospheric Observatory for Infrared Astronomy, or SOFIA for short, was an engineering marvel. Researchers at NASA and the German Space Agency installed a 38,000-pound, 100-inch reflecting telescope inside a Boeing 747SP. Then, they developed a garage door-like device in the aircraft’s main section that could open mid-flight to give the telescope a clear view of the cosmos. The team figured out how to stabilize the huge instrument while the plane was hurtling through the air at 38,000 to 45,000 feet, which was akin to “keeping a laser pointer steady on a penny from ten miles away,” per NASA.
But after eight years of scientific operations above the clouds that resulted in numerous discoveries, SOFIA’s mission came to an end in September due to budget constraints. On Tuesday, the unique observatory will make its final flight and head to the Pima Air & Space Museum in Tucson, Arizona.
Pima is one of the largest aerospace museums in the world and is already home to more than 425 aircraft from around the globe. With its six hangars, 80 acres of outdoor display space and a restoration facility, the museum is well-equipped to become SOFIA’s permanent and final home.
Planning is now underway to determine how best to display SOFIA to the public. NASA is sending other SOFIA-related artifacts to help the museum build out its exhibition.
“The SOFIA mission has a powerful potential to inspire, from its discoveries about the unknown in our universe to the engineering achievements that broke new ground, to the international cooperation that made it all possible,” says Paul Hertz, senior advisor for the Science Mission Directorate at NASA, in a statement. “We are excited SOFIA will continue to engage a diverse new generation of scientists, engineers and explorers.”
After it reached full operational capacity in 2014, SOFIA’s telescope observed mid- and far-infrared light from nearby galaxies, stars, star-forming regions, the moon and other celestial bodies. By soaring through the stratosphere, the specialized aircraft was able to fly above 99.9 percent of the water vapor in Earth’s atmosphere, which typically gets in the way of ground-based telescopes.
SOFIA’s observations, made over the course of 732 nights, gave astronomers valuable insights into cosmic events and objects.
The mission helped scientists better understand magnetic fields and the roles they play throughout the universe; it also offered new insights into the process of star formation. The observatory confirmed the presence of water in an area of the moon that’s illuminated by the sun, suggesting that water is not limited to cold, shadowy regions. After astronomers spent decades searching for it, SOFIA also made the first detection of helium hydride, which scientists say is the first type of molecule that formed in the universe.
The nimble design also allowed astronomers to study fleeting, time-sensitive events, such as when Pluto passed between the Earth and a distant star, backlighting the dwarf planet. This rare opportunity allowed scientists to analyze Pluto’s atmosphere. SOFIA’s crew also jumped into action when astronomers spotted a nearby supernova, or exploding star, in 2014, and when a protostar in the Cat’s Paw Nebula sent out a bright outburst of energy.
The flying observatory also shed light on Jupiter’s atmosphere, comets, asteroids and the distribution of materials in space, including water. Closer to home, SOFIA also helped researchers analyze Earth’s upper atmosphere, which has historically been a difficult region to study.
“From deepening our understanding of water on the moon to revealing the invisible forces of cosmic-scale magnetic fields, none of it could have happened without the hundreds of people who contributed their expertise to the SOFIA mission,” says Naseem Rangwala, SOFIA’s project scientist at NASA’s Ames Research Center, in a statement.
Despite these and other accomplishments, SOFIA’s mission came to an end in September, after an evaluation determined that its “science productivity does not justify its operating costs,” per NASA. The new James Webb Space Telescope, which launched in December 2021, has now picked up the mantle for infrared observations.