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Ever since X-1 pilot Chuck Yeager broke the sound barrier in 1947, NASA researchers have worked to fix it – or at least reduce the window rattling sonic booms produced when planes fly at supersonic speeds.

Sonic booms are shock waves caused by an aircraft flying faster than the speed of sound. They have been the subject of extensive aeronautics research for more than 60 years, according to internationally known sonic boom expert Domenic Maglieri.

"NASA got into the business [of sonic boom research] in 1958," said Maglieri to a crowd of researchers and students at a NASA Langley Research Center Colloquium series lecture.  Maglieri, a researcher at Langley then, was one of the first engineers to launch a major effort to assess shock-wave noise.

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Maglieri worked at NASA Langley for 35 years, but even after he retired in 1986, he continued studying sonic booms as part of his job for Eagle Aeronautics. One of the surprising facts he shared with the audience was that planes going slower than the speed of sound, or Mach 1, can also create sonic booms. "We do have sonic booms from aircraft flying less than supersonic speeds at nine-tenths Mach," he said. Maglieri added that both wind tunnel and flight data confirmed that fact.

Researchers have collected a lot of data in the six decades of boom studies. Maglieri alone has authored or co-authored more 160 publications, 100 of which are on sonic boom. "We have a database on every aircraft in the U.S. that goes supersonic, except the B-1 [bomber]," he said. "That includes the [space shuttle] orbiter."

Engineers also have gathered information about community response to sonic boom noise. The first study was conducted in St. Louis, Missouri, in the early 1960s. Researchers measured the effects of 66 booms created by a U.S. Air Force jet over a period of six months. "Three things came out of the St. Louis community test," said Maglieri when commenting about the residents' reactions and their assessment of sonic boom annoyance.  "One was startle. Another was rattle and the third concern was the probability of damage."

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According to the book "High-Speed Dreams, NASA and the Technopolitics of Supersonic Transportation, 1945-1999," in which Maglieri's research is also mentioned, NASA continued working to overcome technical challenges to supersonic passenger flight – especially in the areas of sonic boom.

So concerned was the Federal Aviation Administration about the annoyance of sonic booms to communities that it banned flight at supersonic speeds over land in 1973. The European Concorde, which offered supersonic passenger travel to a select few, was only allowed to fly above the speed of sound over water during its years of service,  1976 to 2003.

NASA and other researchers kept working to study and reduce boom noise. One concept they investigated was whether shaping the plane differently could change the boom.

"The theoreticians can say it works, but until you fly it, I am not buying it," said Maglieri. "They did it with the shaped sonic boom demonstrator. They took an F-5E [jet] and modified it." That test was successfully completed in 2003.

The next step, according to Maglieri, is to build a low boom flight demonstrator from scratch. NASA has already worked with Lockheed Martin and The Boeing Company on concept feasibility studies.

"I believe we will go supersonic over land," said Maglieri. "I can't believe we're going to go on forever not flying above Mach 1. Advances are now coming so fast. We're going to get there. It's just a matter of time."

And Maglieri says he intends to be around to see the demonstrator's first flight.