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[ Music ]

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[ Background Noise ]

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>>Test 1.

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>>I think that's good Natalie, let it go.

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>>This is the last test of the X-56A that we're
doing in the Loads Lab and we are doing a

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Swing Test, which is to determine the Moment
of Inertia of the vehicle.

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Moment of Inertia, you can think of that as
angular momentum, how hard or easy is it for

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the vehicle to pitch up and down.

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So when it's flying in the air, you want to
determine 'Ok, if we deflect the control surface

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a few degrees, is it going to rotate sharply
down, or rotate sharply up?

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Or how much force do we need to apply while
it's flying to make sure that we really understand

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the flight dynamics of the vehicle?'

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It's currently configured right now in what
we call the IYY, or pitch, inertia, so you

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can see it's swinging about the fore and aft
of the vehicle, and this is the configuration

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we're most concerned about to determine this
information experimentally.

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>>Test number 4, Natalie, go ahead, swing.

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[ Music ]

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Ok, let it go Natalie.

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>>IMU is go and recording.

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>>Tracker is recording.

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>>To determine this moment of inertia, we need
to know what the weight of the vehicle is,

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the approximate CG location, and the period
at which it is doing each oscillation.

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We measured a period using multiple different
tools.

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One of them was a simple stopwatch, so we're
just counting the oscillation as it's going

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across the same position.

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We also have this laser tracker that is connected
to a laser ball on the vehicle.

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We have an attached inertial measurement unit
on the very back.

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We also have the onboard system measuring
angular rates as well.

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So all these independent sets of data, we're
essentially just trying to get period, but

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it's viable to have different sets of data
so we can compare to make sure that we have

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the best information possible.

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So we'll compare the accuracy of the laser
tracker, the IMU, the onboard systems, even

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the stopwatch, just as a checking measure,
to make sure our data is correct.

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We test in two different lengths, the lengths,
you can see those hangar plates which is connecting

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between the pivot and the vehicle, what this
helps us do is allow us to obtain two independent

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sets of data.

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It's essentially two independent tests we
can do for not a lot more work, to get some

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good data to work with.

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After we wrap up and bring the test article
back down, we're gonna analyze the data to

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make sure that we have all of our period information
accurately, make sure we calculate our CG

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location accurately, and we accounted for
all the weights.

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And once we do this analysis, we'll hand over
the information to update our finite element