NASA to Conclude Boeing 747SP SOFIA Mission

DALLAS - This fall, NASA will conclude operations of its modified Boeing 747SP, the Stratospheric Observatory for Infrared Astronomy (SOFIA).

SOFIA carries a 2.7-meter (106-inch) reflecting telescope (with an effective diameter of 2.5 mt, or 100 in). The modified Boeing 747SP is one of the most iconic aircraft flying in the skies today.

SOFIA with open telescope doors. Photo: Armstrong Flight Research Center of NASA. ID: ED09-0352-03. Public Domain.

SOFIA's Last Leg

The aircraft completed its first five-year mission in 2019 and is currently operating on a three-year extension to its mission. The mission is scheduled to conclude on September 30, 2022.

According to NASA, a peer-reviewed report concluded that “SOFIA’s science productivity does not justify its operating costs.”

Infrared image taken by SOFIA’s upGREAT instrument. Credits: Left: Dylan O’Donnell; Right: NASA/SOFIA/J. Bally et. al

The SOFIA Mission

Flying into the stratosphere at 38,000–45,000 feet puts SOFIA above 99% of Earth’s infrared-blocking atmosphere, allowing astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. In 2010, SOFIA was used to observe its first astronomical targets, the planet Jupiter and the Messier 82 galaxy.

Since then, the aircraft has made various deployments across the globe to observe and image faraway galaxies and planets, primarily in the Southern Hemisphere.

Earlier this year, the aircraft traveled to Chile, where it captured unique images of two galaxies in the Milky Way, the Large Cloud and the Small Magellanic Cloud, which scientists predict could merge with our galaxy within billions of years.

The SOFIA aircraft is photographed during a test flight in 1998 still mostly in United Airlines (UA) livery. A black square has been painted on the aft fuselage to indicate the location of the door that will be opened in flight to allow the telescope access to the sky. Photo: By NASA/USRA 1998, Public Domain

From Pan Am to NASA

The aircraft, N747NA, was first delivered to Pan Am in 1977 as N536PA before being delivered to United Airlines (UA) in February 1986.

In 1997, the aircraft was purchased by NASA and underwent significant modifications and trials from 1998 to 2007 before reaching full capability in 2014.

Some of the modifications included creating a cavity in the aircraft for the telescope, retrofitting the aircraft’s structural system, and retrofitting the interior to create a working space for scientists.

The modifications to SOFIA were some of the most ambitious in the aviation industry, which created significant challenges for engineers.

SOFIA on approach. Photo: Luca Flores/Airways

Featured image: SOFIA soars over the snow-covered Sierra Nevada mountains with its telescope door open during a test flight. SOFIA is a modified Boeing 747SP aircraft. Credits: NASA/Jim Ross