HAMPTON, Va. — Imagine you're in your living room, perhaps sitting on the couch with a cold beverage after a long day at work, when you hear a startling boom – something like an explosion that shakes your home and rattles the windows. Now imagine you live by an airport and that happens dozens of times a day.
These so-called sonic booms are one of the biggest hindrances to commercial supersonic flight. Air around planes moving faster than the speed of sound expands and compresses rapidly, creating shockwaves that produce the crackling boom sound on the ground.
NASA plans to overcome that problem. A team at the agency's Langley Research Center is leading a $500 million project to quiet sonic booms and convince authorities that supersonic air travel is feasible in the next decade.
"Long-haul commercial flights are not that comfortable. The seats are getting smaller and service is getting less," said Craig Nickol, one of the project's managers. "Anything we can do to make that time shorter, to get to their destination faster is a good thing. ... NASA's goal is to enable that kind of future."
Think New York to Los Angeles in under three hours.
In April, NASA awarded a nearly $250 million contract – about half the project's total budget – to Lockheed Martin to build an experimental plane that will mitigate sonic boom and instead produce a much quieter "sonic thump."
The plane design features a long, narrow nose and aftward T-tail. Last week it was dubbed the X-59 QueSST. The naming was "a big deal" to those in the line of work, Nickol said.
Though Lockheed is building the aircraft in California, Langley is heading the Low-Boom Flight Demonstration team.
David Richwine, the mission's technology deputy, said NASA officials have been studying supersonics for nearly seven decades but have been "treading water for the last 30, 40 years or so because of regulatory changes and a ban on supersonic flight over land because of sonic boom."
The Federal Aviation Administration put that ban in place in 1973.
Planes have long been capable of flying supersonically at more than 767 mph. The first did in 1947. The famed Concorde, a British passenger airliner, flew over the Atlantic at twice that speed before it was retired in 2003 due to low passenger numbers and fuel consumption concerns.
Meanwhile, NASA had a High Speed Research team in the mid-'90s to design a Concorde replacement, said the agency's Steve Williams. Technology they developed back then to give pilots better vision, without the heavy "drooped nose" of the Concorde, has been invaluable for the X-59. It's called the external vision system, or XVS.
"We had the knowledge," said Williams, the XVS tech lead. It made sense for Langley to lead the low-boom team "because we were already doing this."
The external vision system is necessary because of the new plane's shape. At just under 100 feet long and 30 feet wide, the aircraft has a very long, slender nose to stop shockwaves from forming.
The problem? It's so narrow that it eliminates a central window in the cockpit, preventing the pilot from seeing out front.
NASA's high-tech solution aligns two cameras – one on the front of the plane, one on a pop-out below – that serve as a replacement for the human eye. On the X-59, a pilot will look at a computer monitor instead of a window. Officials use an algorithm to automatically line up the images from both camera feeds.
The system is one of NASA's major innovations for the project, but Williams said it simply involved merging existing hardware and algorithms.
Langley has also been testing the dynamics of supersonic noise in an "interior effects room" – a model living room surrounded by 104 loudspeakers. The X-59 is predicted to produce a perceived decibel level of 75, well below the 100-plus of an F/A-18.
The plane should be completed and take off for a test flight in 2021, cruising at 55,000 feet at 940 mph.
Some have been wary of commercial supersonic travel, Richwine said, despite the allure of flight times sliced in half. The market would likely start with small, private jets.
"Some of the resistance we've had in the past is people have commented, 'This is for the 1 percenters, this is for the rich person,'" Richwine said.
But the market would eventually adapt and expand, he said, as with any early industry like automobiles. Faster flights could also help in speed-sensitive situations such as organ transplants.
"If the U.S. can stay out in the forefront, have the control of that supersonic market, that would be huge," Richwine said. "You've really got to think about the economic benefit of the people working on these airplanes."
Starting around 2023, several yet-to-be-chosen communities will get a taste of how the new plane sounds.
The X-59 will fly over a handful of regions and collect feedback from residents about their level of annoyance with the "sonic thump." NASA officials said they "wouldn't be surprised" if Hampton Roads is one such location.
This November, NASA officials plan to fly over Galveston, Texas, and practice the community technique. Though the X-plane won't be ready, a pilot in an F/A-18 about 5 miles offshore will dive and fly in an oval pattern to produce a boom that quiets as it reaches the coastal community. A typical sonic boom can reach 25 miles on either side of a plane's flight path.
Ultimately, NASA will turn over all this data to the FAA, in the hopes the agency can lift its ban and set standards for supersonic air travel. Americans could be buying plane tickets by the end of the next decade.
Nickol said it's a unique project for NASA because of the purely civilian use – the military has not prioritized or provided funding for this supersonics research.
"I've always been an airplane nut," Nickol said. "Building and flying a new airplane, an X-plane ... it doesn't get much better than that in our business."
©2018 The Virginian-Pilot (Norfolk, Va.)