NASA wants to build a new series of X-planes to increase fuel efficiency and reduce noise and pollution from commercial aircraft. After years of flat or declining budgets in aeronautics research, NASA will seek a substantial increase for the coming fiscal year and beyond. The agency’s administrator, Charles Bolden, will speak more about this request later today at Reagan National Airport in Washington DC, but Ars has learned details of the plan.

The proposed budget increase of $3.7 billion (£2.7 billion) over the next decade would allow NASA to work on dramatically improving both subsonic and supersonic flight. In an interview, Jaiwon Shin, the associate administrator for NASA’s Aeronautics Research Mission Directorate, told Ars that the agency has been working with industry and academic partners to research several “revolutionary” technologies. To take the next step and begin actually flying these concepts, however, NASA needs to build a new generation of X-planes. And that costs money.

Shin said the design-and-build phase will take about four to five years, after which time the planes would be tested at Armstrong Flight Research Center in California and Langley Research Center in Virginia. If successful, these concepts might be incorporated into commercial fleets within about a decade, and through fuel savings, noise, and emission reductions, they could save the aviation industry as much as $255 billion (£183 billion) over 25 years, NASA estimates.

Here are a couple of the concepts we discussed with Shin.

Subsonic flight

One of the most intriguing concepts NASA has been working on is a version of a hybrid-wing body aircraft that has turbofan engines on top of its back end, flanked by two vertical tails. This unconventional-looking airplane can fly at the same speed as commercial airliners, but it has other, significant benefits.

NASA/Boeing

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On the more familiar tube-and-wing modern aircraft, the engine nacelles, which are mounted under the wings, have gotten so large that they generate a lot of drag, Shin said. These nacelles are also reaching their physical limitations in terms of size, because on some aircraft they almost touch the ground. The new design solves this problem by mounting the engines on top of the fuselage. In addition to reducing drag and allowing for larger, high efficiency engines, this hybrid-wing body design also incorporates tail shields that dampen the noise produced by the aircraft.

NASA has seen fuel consumption reductions of up to 50 percent, nitrogen oxide emissions reduced by 75 percent, and noise levels drop by 42 decibels when testing high-efficiency engines with this configuration, Shin said. “This airplane, when it is actually produced and taking off and landing, will generate noise that is well contained within the airport boundary,” Shin said.

NASA has other concepts too, such as electric propulsion, long but narrow wings, and double-wide fuselages. All show promise in computer simulations, but to prove the concepts they must be built and tested under real flight conditions.

“We have been working with industry all along, but as you are well aware of, industry is not really good at taking high-risk projects on,” Shin said. “They are more evolutionary than revolutionary. Government funded research is focused on high-risk, high-payoff technologies, and all of these flight ideas are pretty high risk. We feel it is an appropriate government role to invest in X-plane research to validate the technologies that can benefit the country as a whole.”

Supersonic flight

The X-plane program began back in 1945 when the forerunner of NASA, the National Advisory Committee for Aeronautics, designed and built the Bell X-1 in conjunction with the US Air Force. In 1947, Chuck Yeager would make the first crewed supersonic flight in an X-1 over California, reaching Mach 1.06 after being drop-launched from a modified B-29 bomber.

Supersonic flight, however, has remained on the edge of commercial viability. From 1976 through 2003, the Concorde flew transatlantic flights for Air France and British Airways, but the program was discontinued due to a lack of customers and other issues.

One of the biggest impediments to viability, Shin said, is a complete ban by the Federal Aviation Administration and other international flight agencies on supersonic flight over land due to sonic boom issues. “That’s a big reason why companies haven’t entered into this market, and up until this point we didn’t know how to alleviate this sonic boom intensity,” he said.

Now, however, Shin said NASA has developed designs that break one big shockwave into several smaller shocks. One such concept is an airplane with a long, spiky nose that reduces the intensity of the sonic boom that reaches the ground. The idea, Shin said, is that people in this “boom carpet” area may hear a bit of rumbling in the background, but not a disruptive boom.

After NASA develops the concept vehicle, the plan is to fly it over developed areas and then survey the general public about the flight. Did they notice the sonic boom? Did it bother them? With survey and scientific data, NASA and aviation companies could approach regulatory agencies about potentially allowing overland supersonic flight under certain decibel restrictions.

Shin said he’s excited about the possibility of showing off these unconventional aircraft designs to the public and flying them over populated areas—once their safety has been determined. “We can envision these planes are going to generate a lot of excitement,” he said.

First Congress must act, however. For fiscal year 2017, the President’s request seeks an increase in the aeronautics budget from $640 million to $790 million. Congress has had higher priorities in other areas of the NASA budget, such as the large Space Launch System rocket, so it’s not clear it will support this 23 percent increase in aeronautics funding.