Nasa wants to use its engineering prowess to kickstart a faster, quieter and cleaner era of aviation
By Richard Benson
When Nasa began developing its daringly experimental X-planes during the Cold War, it was with a focus on high-altitude, high-speed flight with missile and reconnaissance technologies. As the world has changed, so have Nasa’s priorities, and when administrator Charles Bolden announced the “New Aviation Horizons” (NAH) series of X-planes in April 2016, the aim was not military capabilities but eco credentials.
New Aviation Horizons is the centrepiece of the Environmentally Responsible Aviation (ERA) project, which aims to develop technologies that allow the aviation industry to fly more people longer distances, while using less fuel and producing fewer emissions and noise. “A tall order,” Bolden concedes, but a challenge that he believes will inspire “a truly revolutionary era of aviation”, unlike anything seen since the dawn of the commercial jet age.
Nasa’s scientists claim that by 2050, new aircraft could be using half as much fuel, emitting 75 per cent less pollutants, and making 12 per cent of the noise of 2016’s models. All that could save airlines $250 billion between 2025 and 2050.
The first NAH X-plane, the battery-powered X-57 Maxwell, is due to appear in 2017. An experiment in the distribution of propulsion, its 14 electric motors will be integrated into the long, thin wings, powering a large propeller at each tip for use when cruising, and 12 across the leading edges for take-off and landings. Whereas in conventional aircraft the greatest fuel efficiency is obtained by flying below top speed, electric propulsion allows pilots to cruise both efficiently and quickly, reducing energy use by a factor of five and cutting costs for small planes by up to 40 per cent.
After this, other craft – Nasa plans to build five X-planes between now and 2026 – will explore more propulsion possibilities, software systems and new composite materials. These new materials will reduce weight, and therefore fuel efficiencies, and also allow for radical new shapes. Wings will have very high aspect ratios – which is to say they will be long and thin – and fuselages will be completely transformed, as the new materials can withstand high pressure without the need for rounded shapes. One of the planes is likely to have a body integrated with its wings, so that it resembles a huge blade.
Such shapes and materials are likely to feature in the QueSST (Quiet Supersonic Technology) jet, perhaps the most attention-grabbing of the mooted planes. The QueSST, being developed with Lockheed Martin, is intended to be a new, “low-boom” supersonic craft, that could eventually fill the gap left by Concorde. Its engineers will seek to replace the severe sound-pollutant sonic boom with a soft thump, or “supersonic heartbeat”, which would mean it could attain its top speeds over land, rather than having to wait until was over the sea.
Will we really see these sorts of ideas crossing over into everyday life? That’s certainly the intention, says Rich Wahls, a Nasa aerospace engineer and strategic technical advisor for Nasa’s Advanced Air Vehicles Program, which is part of ERA. “Whether we’re looking at technologies for adaptive trailing edges, hybrid electric propulsion technology or lighter weight fuselages, our goal, in part, is to support companies in producing products that will benefit the public,” he explains. “The aim is to develop technology to a point that it reduces the risk to a level at which that industry can incorporate it into their designs. It’s meeting the markets’ need to produce better aircraft.”