You can’t miss the engineering marvels when you walk into the hangar at NASA’s Armstrong Flight Research Center. They are everywhere. When I was at the facility last year, I saw various vintages of aircraft scattered throughout the hangar. Cranes scuttled about, hauling large pieces of equipment from place to place. Staff hustled along marked walkways, running tests and preparing instruments—a beehive of activity.
What you can’t tell at first glance, though, is that these beautiful machines—new and old—aren’t just marvels of engineering. They are also masterpieces of repurposing.
I’m a bit of a recreational space geek—so I was there to visit the Stratospheric Observatory For Infrared Astronomy (SOFIA)—basically, a flying laboratory. Interestingly, SOFIA wasn’t always a winged science lab. It used to be a 747; NASA repurposed it into a state-of-the-art astronomical instrument.
SOFIA’s job is to see the invisible. It flies at between 39,000 and 45,000 feet, soaring above 99% of the water vapor in the earth’s atmosphere. Up there, beyond the clouds, SOFIA’s telescope gets a better view of the stars than any telescope on the ground ever could. In fact, from its airy vantage point, SOFIA can see the universe from an entirely different perspective: in infrared, a wavelength invisible to the human eye.
Before boarding, I toured surrounding labs buzzing with student interns, engineers, and scientists. In one lab, the instruments are tested before they are loaded onto the plane. Interns work to add additional components to existing mounts and plugs, expanding SOFIA’s instrument capabilities to meet the current needs of scientists. Despite the sophistication, resources here are precious because they are few—there is no budget in the SOFIA program to build or buy new instruments. Each instrument was a huge investment, so future-proofing is essential to making the most of that investment.
A second lab hosts a giant metal vacuum chamber. This lab is for repair. The aluminum-silver coating on the mirror of SOFIA’s telescope wears out. Exposed to the elements—as all telescope mirrors are—these expensive custom mirrors lose their coating over time.
How do you repair a giant mirror, two-and-a-half meters in diameter? Answer: With a little engineering.
SOFIA’s primary mirror measures in at 2.5 meters in diameter. Photo cred: By NASA/Tom Tschida, via Wikimedia Commons
Once every few years, SOFIA’s mirror is carefully hoisted out of the belly of the 747 by a special crane. The mirror is then driven into the lab through a roll-up door and lowered into the giant vacuum chamber. A pump evacuates the chamber and the mirror is chemically cleaned and prepped for coating. A vaporized aluminum and silver coating is then added, which bonds to the glass to form the new surface of the mirror. It only takes about an ounce of vaporized aluminum-silver to coat the entire mirror.
Repairs on the SOFIA are critical. The research done onboard provides a basis for many cosmological theories—examining things like how stars die and how new solar systems are born. So, this winged astronomy lab needs to last. SOFIA has a projected lifespan of 20 years, during which time it will fly more than once a week.
Back in the hangar, repair and maintenance technicians bustled about SOFIA. On one side of the hangar, piles of old 747 parts are stacked on the floor. Repaired and repurposed parts are SOFIA’s lifeblood. When 747SPs stopped being manufactured, NASA started hoarding all the spare parts it could get its hands on. Hopefully, these parts will keep SOFIA running for the rest of its useful life.
SOFIA is state-of-the-art. And as I toured around the facility, it occurred to me that we usually think of state-of-the-art as something shiny, expensive, and (especially) new. Not so with SOFIA. The flying, repurposed laboratory proves that repair and reuse are not only practical, but absolutely necessary for cutting-edge science. Hundreds of scientists, teachers, and technicians will use the information that SOFIA gathers over the next 20 years to build a better picture of the universe—to unlock its mysteries.
Back on board, crew members calibrated equipment and ran flight tests. Dremels, riveters, and drills echoed in the hull of the plane. These are the sounds of SOFIA’s ground crew, heroes of repair, keeping a watchful eye on the universe.
Photo cred: “SOFIA ED10-0182-01 full” by NASA photo / Jim Ross. Licensed under Public Domain via Wikimedia Commons.