JOSH: Right now, there are more than a thousand
thunderstorms happening on Earth. Some 6,000 flashes of
lightning will occur in the next minute.
That lightening can be devastating, especially to tall structures...
That’s why NASA is taking steps to protect its most valuable assets...
And it’s doing so with an innovative new strategy...
Learn the secret to NASA’s launch pad lightning
protection system... next on Real World.
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[Thunder bolt cracks] JOSH: Whoa!!! Thunderstorms
and lightning can be some pretty scary stuff...
And I’m just standing in front a green screen video effect wall...
Imagine if I was actually outside in the middle of a thunderstorm...
Well NASA’s next generation space exploration vehicles
aren’t going to be able to avoid being in the middle of
some potentially dangerous storms...
Launch Complex 39 at the Kennedy Space Center in
Florida is the site where the Ares I and Ares V rockets
will launch from, taking crew and cargo to the moon and beyond.
And lightning is a well-known danger in that part of Florida.
So scientists and engineers have been hard at work
designing a new lightning protection system that's
above and beyond any the space center has ever seen.
JON COWART: There is a better method called Rolling Spheres.
JOSH: Jon Cowart is the Ares I-X deputy mission manager.
JON: For the past 50 years the way people have done
lightning protection was using this thing called the "Cone of Protection."
JOSH: The cone of protection was used by NASA on the
Apollo program and is pretty common beyond NASA.
It’s the basis behind the lightning rod.
A fixed rod or mast is built high into the air, creating a
"cone of safety." In theory, the height of the tower
equals the radius of the base of the cone, inside of which,
is relatively safe from the lightning.
You can find examples of this type of shielding on top of
roofs, water towers, barns, silos... just about everywhere.
It is pretty efficient for buildings, but with so much
at stake, NASA needs something better.
They upgraded for the shuttle’s system, with a
single lightning mast on top of the structure, with two
curved wires, called catenary wires, going to the ground.
Catenary wires can help divert lightning strikes.
But that upgraded system still has its problems.
JON: You don’t want what we call a "direct attachment."
If the lightning bolt hits the wire like it is supposed
to and travels down in to the ground, you still get a huge electromagnetic pulse.
But that pulse is much less than the one you would get if
it actually got a lot closer to the vehicle and hit a big
service structure or even attached itself to a vehicle.
JOSH: The energy from a lightning bolt can be hotter
that the sun and can fry valuable electronics.
To explain it better, we check in with Richard Byles,
from the Virginia Air and Space center...
RICHARD BYLES: Lightning is a discharge from cumulonimbus clouds.
The Clouds develop a charge when the particles of water
and ice in the cloud roll through.
When the bottoms become generally positive and the
tops become generally negative.
And of course if you got negative charges at the top
and positive charges at the bottom, they try to get to each other.
And as the cloud moves across the landscape it also imparts
that positive charge to the ground underneath it.
And so what happens with lightning is it comes down
through the cloud and then right to the ground and of
course it always tries to find the tallest thing.
JOSH: But the rolling spheres system will significantly
increase the shielding level and further separate the
electrical current from important hardware.
JON COWART: Rolling spheres, which gives you much better protection.
Those three towers will actually have wires coming
towards the middle, right above the pad. They will form into a nice little
opening that the vehicle can fly through.
It gives you much better lightning protection than
what shuttle has had all these years.
As the positive and negative electrons begin to build up,
this, the wires and the masts itself will actually create
and easier path for the lightening to get to ground.
The wire actually acts as a conductor, the lightning will
pass into it, go out to the wires and then it travels
back down to the ground in order to
dissipate that huge electromagnetic energy.
JOSH: The system features towers more than 150 meters
tall with an additional 30 meter fiberglass mast atop each one,
supporting the wire catenary system.
It also has 216 pilings extending down 15 meters below ground.
The massive steel towers were partially assembled
horizontally on the ground, and then lifted into the
vertical position by a 60-story-tall crane.
The first Constellation vehicle, the Ares I-X test
rocket will take off from Launch pad 39B in 2009.
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