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Joel Tumbiolo, Delta Launch Weather Officer
08.16.06
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Interview with Joel Tumbiolo, Delta Launch Weather Officer

Transcribed by Corey Schubert

WOMAN: You're listening to NASA Direct.

GEORGE DILLER: From the Kennedy Space Center in Florida, I'm George Diller.

NASA's thrilling science missions all begin one way: with a ride into space inside a rocket! Launching those rockets is no easy task and even when the countdown has begun, the work is not over.

As the NASA launch team prepares for launch, a weather team is right there with them keeping an eye on the sky! A perfectly beautiful day can spell a "no go" if winds are too strong or a thunderstorm is looming. Here to explain more about how launch day weather is tracked is Delta Weather Officer Joel Tumbiolo from the 45th Weather Squadron at Cape Canaveral Air Force Station.

Joel, thank you for being here.

JOEL TUMBIOLO: Hello, George. Thank you for having me.

DILLER: How are the weather criteria, or weather rules for expendable rocket launches similar or different from the space shuttle weather criteria?

TUMBIOLO: Let's talk about the similarities first. Regardless of it's a space shuttle or expendable launch vehicle, all the lightning and triggered lightning weather constraints -- range safety constraints, as we call them -- are all the same. We monitor both clouds, thunderstorms and thunderstorm anvil clouds, and again, all of those rules are the same regardless of whether it's a space shuttle or expendable launch vehicle.

Now, the differences come into play when we're talking about winds, both ground winds and upper-level winds. Those are different for each particular launch vehicle.

DILLER: How is a rocket's weather criteria determined? Is it based on what type of expendable launch vehicle will be used?

TUMBIOLO: Again, all the rules are the same for the expendable vehicles when we're talking about thunderstorm-related clouds and anvil clouds. All those rules are the same. Now again, the only differences for the vehicles are the wind constraints. Those would be the difference between the two and three.

DILLER: What kinds of weather events could cause a scrub for an expendable launch vehicle, such as a Delta?

TUMBIOLO: A variety of things: a thunderstorm within 10 miles of the launch pad, a thunderstorm anvil cloud within 10 miles of the launch pad, a lightning strike within 10 miles of the launch pad, a cumulous cloud that has not necessarily developed into a thunderstorm but is large enough and is close enough to the launch pad such that it could cause triggered lightning, and other things, such as ground winds exceeding a certain level would also cause a scrub.

DILLER: How is it determined whether the Delta can handle wind shears?

TUMBIOLO: We use upper-level balloons, rawinsondes, as we call them. We launch several of them during the launch countdown and from the data that we get from those balloons -- upper-level winds, direction and speed -- the Delta engineers, they crank these numbers through their computers and they're able to determine if the winds will affect, the wind shears will affect the vehicle as it's going through space.

DILLER: Can you explain a little bit more about what a rawinsonde balloon is?

TUMBIOLO: A rawinsonde is a balloon that has hanging from it a series of instruments, instruments that gather data such as temperature, humidity, wind direction, wind speed, pressure, things of that nature, and these balloons are released from the ground all the way up to 100,000 feet into the atmosphere. And as this balloon is rising, all that data is transmitted back down to the ground and we use this to analyze our weather criteria.

DILLER: What is the difference between a ground wind and an upper-level wind?

TUMBIOLO: The ground wind again varies on the launch vehicle. For the Delta vehicle, the main level is 90 feet, so the ground level, we consider winds at the 90-foot level being the ground level, and then upper level winds, the main two levels for Delta are the 13- (to) 14,000-foot region and around the 33- (to) 34,000-foot region.

DILLER: What is launch day like for you?

TUMBIOLO: Sometimes it's very exciting. Obviously, if there's weather in the area, it's very exciting. There's a lot of communication between the launch team, the launch weather team and, again, it all depends on the weather. If the weather is very nice and benign, and then we still monitor our constraints, but it's not nearly as exciting as if there were thunderstorms in the area.

DILLER: What are you doing up until you give the weather's final "go for launch"?

TUMBIOLO: We are monitoring both our range safety lightning and triggered lightning constraints and the ground wind constraints throughout the countdown.

DILLER: Joel, thank you very much for your insight!

TUMBIOLO: Thank you, George.

DILLER: From the Kennedy Space Center in Florida, I'm George Diller.

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