After almost six years of flights, NASA announced in 2013 that its remotely-piloted blended wing body X-48 flight test project had come to a close, a statement from the organization explained at the time.
The test flights stand as an indicator of NASA's commitment to designing and developing new aircraft that reduce noise pollution and carbon emissions.
An aircraft designed to meet NASA's environmental goals
The X-48 was a manta-shaped demonstrator aircraft with two model variations that carried out 122 flights. The aircraft's last flight occurred on April 9, 2013, while the first took place in 2007.
The X-48 was designed by The Boeing Co. and was built by UK-based Cranfield Aerospace Limited, while NASA carried out the flight tests. It was built as a demonstrator for a future Hybrid Wing Body (HWB) aircraft design derived from concept studies carried out at NASA's Environmentally Responsible Aviation project, which aims to develop aircraft designs for 20 years from now.
"We have accomplished our goal of establishing a ground-to-flight database, and proving the low-speed controllability of the concept throughout the flight envelope," Fay Collier, manager of NASA’s Environmentally Responsible Aviation project, said in the NASA statement. "Both very quiet and efficient, the hybrid wing body has shown promise for meeting all of NASA's environmental goals for future aircraft designs," Collier continued.
NASA is hard at work developing 'future green airliners'
Two models of the X-48 flew during NASA's test flights, the X-48B and the X-48C. The C model transformed the original B model into an airframe noise-shielding configuration in 2010. The C model also featured an extended aft deck and its wingtip winglets were relocated next to its engines, turning them into twin tails. Lastly, the C model replaced the X-48B's three 50-lb thrust jet engines with two 89-lb thrust engines.
The X-48C had a wingspan of just over 20 feet (6 meters) and weighed approximately 500 pounds (226 kg) thanks to advanced lightweight composite materials. The aircraft could reach a top speed of roughly 140 mph and a maximum altitude of 10,000 feet (3,048 meters). "Our team at NASA Dryden has done what we do best, flight test a unique aircraft and repeatedly collect data that will be used to design future 'green' airliners," Heather Maliska, NASA Dryden’s X-48C project manager, explained. NASA says that the flight control system software it used and iterated on during the X-48B and X-48C test flights are "suitable for further development for potential full-scale commercial hybrid or blended wing aircraft in the future."
The test flights won't be the only ones aimed at supporting NASA's efforts to reduce fuel burn, emissions, and also noise pollution. The U.S. space agency also recently revealed timelapse footage of the construction of its X-59 "quiet" supersonic jet. That aircraft will serve as a demonstrator for a new specially designed nose cone that greatly reduces the sound of the sonic boom. Much in the same way as the X-48, the X-59 is also designed to use less fuel and produce fewer emissions as part of NASA's bid to help fight climate change.