NASA F-18 Flights to Produce
Sonic Booms at KSC
July 25, 2017
NASA's research to advance
supersonic flight will take wing over the launch site for the
agency's storied space program in August.
NASA will fly an F-18
research aircraft, pictured here taxiing to the runway from
NASA's Armstrong Flight Research Center in Edwards, Calif., to
produce sonic booms over Kennedy Space Center. The sonic booms
will be recorded by equipment both in the air and on the ground,
providing NASA researchers with data to help them better
understand the impact of atmospheric turbulence on sonic booms.
NASA's F-18 aircraft were obtained from the U.S. Navy, and are
flown for research support and pilot proficiency.
Teams and aircraft from
NASA's Armstrong Flight Research Center in California, and
Langley Research Center in Virginia, two of the agency's centers
that conduct extensive aeronautical research, will deploy to
Kennedy Space Center in Florida for a nearly two-week flight
The historic spaceport will play host to the second series of
Sonic Booms in Atmospheric Turbulence flights, or SonicBAT,
continuing from 2016's successful supersonic research flights
flown at Edwards Air Force Base in California.
NASA's F-18 will fly at or
above 32,000 feet when it goes supersonic off the eastern coast
of Florida. The F-18's flightpath is positioned in efforts to
keep the strongest-sounding sonic booms away from residential
areas, while still producing sonic booms over Kennedy Space
Center, where the sonic boom sound will be collected by
microphone arrays on the ground. While sonic booms will be more
audible on the beaches north of KSC, Cape Canaveral Air Force
Station will hear "muted," or quieter, sonic booms. Areas
including Port Canaveral, Cocoa, Port St. John, Titusville,
Mims, and Scottsmoor are likely to hear a sound closer to the
rumble of distant thunder, though people may hear an occasional
"muted" sonic boom.
SonicBAT helps NASA
researchers better understand how low-altitude atmospheric
turbulence affects sonic booms, which are produced when an
aircraft flies at supersonic speeds, or faster than the speed of
sound. The upcoming flight series is a key initiative in
validating tools and models that will be used for the
development of future quiet supersonic aircraft, which will
produce a soft thump in place of the louder sonic boom.
"In SonicBAT, we're trying to figure out how much atmospheric
turbulence changes sonic booms," said Ed Haering, SonicBAT's
principal investigator at Armstrong.
NASA is working to develop
an experimental airplane called the Low Boom Flight
Demonstration aircraft, or LBFD, which will be capable of
demonstrating flight at supersonic speeds without producing a
loud, disruptive sonic boom. NASA achieved a significant
milestone in June, 2017, by completing the preliminary design
review of the LBFD with Lockheed Martin Corporation.
The initial series of
SonicBAT flights provided NASA with data on the effect of
atmospheric turbulence on sonic booms in a dry climate. The
upcoming flights will continue that effort by collecting data in
the same fashion to measure the effect of the humid climate of
"Turbulence can make sonic booms quieter, or it can make them
louder. Last summer we tested in the hot, dry climate of Edwards
Air Force Base. We know that humidity can make sonic booms
louder, so we need to test some place wetter, and Kennedy fits
that bill," Haering said.
Sonic boom signature data will be collected from these tests
using audio equipment to capture noise levels both above and
below the turbulence layer, which will provide a comparison of
the sonic boom both before and after it travels through
To do this, a NASA Armstrong F-18 will take off from Kennedy's
Shuttle Landing Facilty and fly off the coast of Cape Canaveral
at an altitude of 32,000 feet. The F-18 will fly a designated
flight path where it will exceed Mach 1, the speed of sound, and
produce a sonic boom.
Meanwhile, NASA also will fly a TG-14 motorized glider, equipped
with a wingtip microphone, at an altitude between 4,000 to
10,000 feet, which is above the low-altitude turbulence layer.
At the test point, the TG-14 will temporarily shut down its
motor and glide. This will eliminate any unnecessary noise,
ensuring that the wingtip microphone will pick up a clean,
accurate sonic boom signature before it travels through any
To collect signatures of sonic booms that travel through the
turbulence layer, NASA, along with partners Wyle Laboratories
and Gulfstream Aerospace, will arrange two microphone arrays on
the ground at Kennedy, each with 16 microphones to collect data.
The project aims to collect data in three different conditions,
including low turbulence, medium turbulence and significant
turbulence, to obtain a stronger understanding of how the
variations impact sonic booms. To monitor these conditions, NASA
meteorologists will be on-site using anemometers to measure wind
speed, a sonic wind profiler to measure wind conditions at low
altitude, and a flux sensor to measure changes due to humidity.
NASA is expecting to fly the F-18 two-to-three times per day,
starting Monday, Aug. 21 and will conclude the end of the month
or early September, focusing on collecting data on a targeted
minimum of 33 sonic booms.
While communities nearby Kennedy and Cape Canaveral Air Force
Station may be able to hear traces of the sonic booms being
produced over the NASA center, Haering said residents have no
reason to worry.
"At the altitudes we are flying, sonic booms from aircraft have
never been dangerous to people, animals or buildings, but they
can be startling," said Haering. "We have carefully planned our
flights so that there is little chance that people in larger
communities such as Titusville to the west, or Cocoa Beach to
the south, will be disturbed. Residents might hear a distant
sound similar to a rumble of thunder. If the actual winds at the
time of our tests are much different from predicted, they might
hear a boom sound like those heard when the space shuttle
landed. That may be startling, but there is no reason to be
Due to the flight path of the F-18 being taken over the Atlantic
Ocean east of the Space Coast, some publicly accessible beaches
to the north of Kennedy that are part of the Canaveral National
Seashore will be able to hear the sonic booms louder than other
"Because we are trying to minimize the impact to larger
communities, beachgoers on beaches such as Playalinda will
definitely hear booms like those of the shuttle," said Haering,
"but again, there is no reason for concern."
Sonic booms can be heard as the result of shockwaves created by
aircraft flying through the atmosphere faster than the speed of
sound. The Federal Aviation Administration, or FAA, currently
prohibits supersonic flight over land due to previously flown
supersonic aircraft and their associated loud, disruptive sonic
Decades of NASA research in supersonic flight, however, has now
resulted in a unique aerodynamic design and technological
advances for an aircraft that will mitigate the sonic boom,
making it considerably quieter.
In February 2016, NASA awarded a contract to Lockheed Martin for
a preliminary design of a quiet supersonic X-plane called the
Low-Boom Flight Demonstration aircraft, or LBFD. This effort
recently completed a successful preliminary design review, and
NASA will soon initiate the next phase of the LBFD concept
through a new contract competition.
This second phase will focus on the detailed design and
fabrication of the aircraft. When completed, the goal will be to
fly the X-plane over communities throughout the country to test
and demonstrate a quiet sonic thump. These flight tests will
also provide data to the FAA for the development of potential
noise standards for future supersonic flight over land.
If the FAA establishes that new sound standards based on the
sonic boom research has become acceptable to the public,
commercial flights that can carry passengers at supersonic
speeds, reducing commercial flight times considerably, could be
just years away.
"Supersonic flight offers the potential to improve the quality
of life of those that fly, by greatly reducing travel time,"
said Peter Coen, NASA's Commercial Supersonic Technology project
Building supersonic aircraft in the U.S. offers a potential for
growth and high-quality jobs in the aerospace and air travel
industries, all of which contribute significantly to the
economic welfare of our country.
"In the nearer term, NASA's development of quiet supersonic
flight technology needs support, interest and engagement from
the community to ensure that the potential sound is acceptable
to those on the ground," Coen said.
The SonicBAT flights in Florida will mark a rare opportunity for
NASA's aeronautics and space operations to comingle, and for
Kennedy, showcases the center's transformation into a 21st
century multi-user spaceport.
"This shows that, as NASA, we are all striving for the same
thing," said SonicBAT Project Manager Brett Pauer. "We're
willing to work together and help each other in any NASA mission
that may be happening, whether it be space-based, which we do a
lot of at our aeronautics centers, or the space centers to help
us out with aeronautics. I think there's a great amount of
cooperation, even more than may be expected, between NASA
added. "It seems to me that ‘one NASA' is the best way to
describe the cooperative spirit that makes it possible for teams
to reach out across the agency, and receive the kind of support
SonicBAT has received from Kennedy Space Center."
But through 13 holes Sunday, Kuchar had pulled a shot ahead of
Spieth before he regained control with three birdies and an
eagle on the 14th to 17th holes to win the Claret Jug, the
tournament's signature trophy.
Three different golfers have now won the first three major
tournaments this year, with Spain's Sergio Garcia winning the
Master's in April and American Brooks Koepka the U.S. Open in
June. The last of the sport's four annual major championships,
the Professional Golfers' Association tournament, will be
contested next month.