NASA Podcasts

Space Shuttle Rollout
09.03.10
 
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A space shuttle liftoff is an awe-inspiring sight -- but the journey doesn't begin on the launch pad.

It has to get there first.

Rollout means moving a fully assembled space shuttle, and its mobile launcher platform, across more than 3 miles of NASA's Kennedy Space Center.

CRAWLER ENGINEER BOB MYERS:
"You try to think of it kind of like a job, but it gives you a real great sense of pride to know that you're carrying the nation's space program on your back."

It begins inside the Vehicle Assembly Building, or VAB, where the shuttle is joined to its external fuel tank and solid rocket boosters.

The entire assembly is built on top of the mobile launcher -- which rests on a set of six, 22-foot-tall pedestals.

The 12-million-pound load is carefully picked up and carried on the back of a crawler-transporter -- a nearly 6-million-pound beast of a machine capable of incredible precision.

It takes 20 to 30 minutes for the crawler's jacking, equalization and leveling system, called the JEL, to lift the entire load high enough to clear the supports.

When the vehicle is ready and the weather is right, the shuttle launch director gives the go-ahead to begin the move.

CRAWLER MANAGER RAY TRAPP:
"Well, probably other than launch-landing, one of the most critical times for the vehicle is between the VAB and the pad. Because there's no weather protection. There's no lightning protection."

The crawler and its extraordinary cargo start off down the 130-foot-wide crawlerway, inching along at the careful speed of almost 1 mile an hour.

A team of about 30 United Space Alliance crawler drivers, technicians, mechanics and supervisors operate the crawler during the move, which takes at least six hours.

The rollout team stays sharp during the 12- to 14-hour shift by taking turns at different jobs.

MYERS:
"So, it is a long evening -- typically we do it at night. But we do try to change out as far as in the driving positions and the other positions on the crawler, so that nobody gets too fatigued or anything like that."

The crawler has identical front and rear driver cabs, a control room and two engine rooms, each with a huge, 2,750-horsepower diesel engine for propulsion.

As slow and precise as the rollout is, crawler drivers have to plan ahead.

TRAPP:
"So you have to really be on your game, and you have to be thinking ahead about where you want to be one, two, three minutes ahead of time."

Even with so much strength and engineering capability, the crawler has a few, more basic needs to support.

There are no meal breaks or bathroom stops once the crawler gets going, so they bring it all with them -- including the bathroom.

TRAPP:
"Anything we need, we bring with us. We're self-sufficient as far as water, electricity. We bring our own food, refrigerator and microwave, and one of the most important things we have with us here on the crawler is our Port-O-Lets."

There's one more critical challenge ahead once the shuttle arrives at the launch pad.

The crawler's JEL system must keep the shuttle level as it moves up the ramp to the top of the pad.

Then, drivers in both cabs position the mobile launcher platform over another set of pedestals, with the help of a high-tech laser alignment system.

MYERS:
"Probably, I'll call it, the culmination of the trip is, of course, taking the crawler and the shuttle and the platform up on the pad and docking it. That's always kind of what you'd call a tense time, and you want to get it exactly right. You want to set it down exactly right."

At that point, the shuttle is secured at the launch pad and rollout is complete.

Now the shuttle is ready to start final preparations for another exciting mission.

TRAPP:
"We're coming down the hill, looking at the vehicle sitting on the pad, knowing that you and your group played a major part in getting that out there."
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