♪
What I would like to eventually see, is a supersonic airliner
that can reduce travel time by a factor of two for the average person flying.
Uh, LA to New York I believe it’s like two, two and a half hours or so.
Currently we’re limited by sonic booms.
There’s no regulation stipulating
what kind of sonic booms can be projected over land.
Right now the rule is no sonic booms over land.
The boom is actually a shock wave, a pressure change…
you think of the aircraft here, that emanates off
the nose of the aircraft.
Sonic booms are uh are really just a sound wave.
Just like you’re hearing my voice now.
Simply put, a sonic boom is an acoustic disturbance created when an aircraft,
actually any projectile, breaks the speed of sound.
It makes a loud crackling noise which can sound like a very loud thunder.
Loud, noisy... got a call today from a woman heard some sonic booms yesterday,
said it frightened her dog.
Wouldn’t want to hear something that’s as loud as a shotgun going off…
um, rattle though your house.
They’re an annoyance, they’re a disturbance.
♪
Conference room discussion: … in real time, get ‘em a block
a couple thousand feet around
the altitude (unintelligible)…
just not going to get it done. Unless it’s an east to west run or the point is far enough,
is uh, close enough to the base (voice tapers off).
The WSPR Project is, it’s part of a bigger effort in supersonics
that NASA is undertaking with the long range goal to have
business jets and airliners that can
fly supersonic over the US,
over populated areas and not
break windows or even disturb the population.
This test in particular
goes towards establishing that
FAA limitation as to what sonic booms will be accepted
just like previous testing was done with airport noise
and seeing the tolerance that can be tolerated there,
uh, we’re doing the same thing with sonic booms.
So we do analysis to figure out what, where the pilot needs to fly.
Um, we can’t do that until we have the weather of the day
because weather plays a huge part in sonic boom placement.
The challenging part for the team
is that the weather balloon was going up while we were briefing,
and the scientists and engineers are getting the data now
and they’re frantically doing all these calculations,
so that by the time I get out to the airplane,
I’ve got these aim points that I’m flying at.
♪
Pilot to Mission Control: That was 123, 1,2,5… and that was NASA 4.
Mission Control: Copy that, 8, 5, 0… And NASA 8,5,0 what we were reading was (unintelligible radio chatter)
As far as the pilot’s concerned, I’m the person they’re talking to,
and they’re expecting me to help them out with their situation
because they’re going to be busy flying the airplane.
Pilot: Flaps up.
The control room is telling me a target time that they want the next boom.
So then I set up a big racetrack out to the Northeast,
trying to time my return so that the boom
hits the ground at the right time.
We use radar tracking from the ground
and we can position information from the aircraft using the radar.
And it tells us where they are in the airspace and
the two parallel lines there – the supersonic corridor –
so it just gives us as a controller on the ground
situational awareness on where they are.
Pilot: And just for info, seems like about 130 knots to …
And uh, 8 5 0, you’re a little broken there
but just wanted to make sure you heard next dive point at 0 8 4 0.
Again we’ve got a steer point out there that I’m going to roll in and aim at,
so actually, about 8 miles prior to that I need to be at,
I need to be at 49,000 ft., and .96 Mach, so still subsonic.
I’m going to roll, pull down 53 degrees nose low, so pretty steep…
somewhere in there we’re going supersonic.
We roll out and we’re trying to time is so that we hit 1.1 Mach
at 40, 00 ft., aimed at that dive point out there, um at 53 degrees nose low.
Oh, and on a proper heading of 246 degrees.
So, if all that works right, and the weather balloon got the right data,
and the engineers did all their calculations right,
then a boom of a specific, uh, volume will hit base housing.
With WSPR we’re trying to get a read back from people on the ground
to some kind of annoyance level.
Um, we have about 110 subjects in the Edwards Air Force Base population
that have been outfitted with several different survey methods.
Pen and paper, iPhone Apple devices, and web devices.
This research we’re looking for low boom signatures mostly.
Different days and different times we’re asking them to do different levels of sonic booms
– sometimes low, medium or high.
So depending on the overpressures from the booms,
how annoying was this low boom, how annoying was this more moderate boom.
And they’ll be submitting surveys
when they hear sonic booms produced by our F-18 jets.
♪
We have about 14-15 different sensors out there to record the sonic booms.
We have what we call our sonic boom field kits.
They’re remotely triggered sonic boom sensors,
they’re on light posts throughout the community.
they’re powered by solar panel arrays and
then we have a microphone sitting towards the bottom on the ground
that actually records the sonic booms.
Then we use that data, convert that into some type of metric like a decibel level,
and compare that to what Jack and Jill heard in their houses during the testing.
♪
What we have is another sonic boom sensor.
This one’s protected by an all-weather dog house.
Once I get the call that the aircraft has started that dive maneuver,
I’ll come over here and wait approximately 2 minutes or so
for the sonic boom to reach the ground and…
Voice on radio/phone: NASA 2, this is (unintelligible)…. .746
…um, come over here and manually trigger it once I hear a sonic boom.
NASA 2, this is NASA Ground. We heard boom the ground…
might be quieter than the last one… pretty low…
We have specific calls that they want us to make,
most of it is so that the team on the ground knows when we’re going to be rolling in,
and then after that when the boom is going to hit them,
so that they make sure that the instruments are all recording and capture that data.
Control Room Voice: 30 second up. 30 seconds.
Larry Cliatt: Copy Airborne.
Ground Operator: Six Seconds.
Pilot: Rolling in 3, 2, 1, now.
Michael Holtz: Copy mark.
Sonic boom sound
Off Camera Voice: How was that one?
Very low…. Just like its supposed to be.
♪
We’re planning on going Mach 1.8, Mach 1.6.
So the cruise speed is roughly twice as fast as
a typical subsonic airliner.
We’re trying to advance to advance the technologies in supersonics
to allow companies that are around today
and that aren’t even around today,
will be able to take the technology that we develop here,
and the understanding of the physics that we do here today,
to open up a whole new market for the future.
If long term we’re going to have business jets and airliners,
they’re going to have to be quieter than military fighters or the Concord…
everyone knows about the Concord, well it made a very big sonic boom
and that disturbed people, it couldn’t fly over land or cities.
♪
The sonic booms we’re producing for WSPR
are what we are simulating will be what we call low sonic booms
or what the next generation of aircraft will produce.
♪
Performing research then becomes technology that’s transferred to the commercial world.
I think that, at the heart, is what NASA’s role is.
♪
To understand where we’ve been, and where we’re headed
and where we are now along that path,
I think is critical for the population to realize.
And this type of research brings what we’re doing
right there to the homes of the people we’re trying to do this for.
It’s a new market, a new type of aircraft.
If the United States takes the lead in that,
that’s jobs for the American tax payer.
In 1947, Chuck Yeager broke the sound barrier.
So I like to think that it’s my job to fix it now.
♪
Sonic boom
♪
Pilot: That’s the Compass Rose behind them…
Pilot: Pointing straight down… holding it, holding it .62 Mach.
Think we covered most of it, so….
Think I gotta get out and uh, go make some booms.