Shuttle Liftoffs Require Precision Launch Pad
The space shuttle is the undisputed star of launch day, with its towering fire and thunderous sound as it soars into the heavens. It gets significant help, though, from a robust supporting actor in the form of a gray launch pad and its weave of wiring, pipes and even a crane.
The pad area is a rough circle more than a mile-and-a-half around. Inside that circle lie huge propellant tanks, banks of high-speed and television cameras, and a water tower that deluges the pad just before liftoff. Baskets anchored beneath high-tension cables stand ready to evacuate astronauts from a shuttle to a protective bunker. The shuttle stack stands in the middle of it all, the ultimate focus of human and hardware attention.

All at a place less than a mile from the ocean that broils in the Florida summer and chills in the winter. As with so many places at NASA's Kennedy Space Center, it's a unique world to work in.

"I kind of feel like I found home," said Kevin Panik, NASA's Pad Facility Integration manager. "I come to work and it's not work. I'm driving in and I'm smiling."

David Sutherland, Pad Operations manager for United Space Alliance, started working at the shuttle launch pads in 1987.

"I'm a lucky guy, no doubt about it," Sutherland said. "I never in my wildest dreams thought I'd have a job like this. Not just being an engineer on shuttle, but being manager of operations. Pretty lucky guy."

Sutherland saw the pad the first time during a job interview.
"I just couldn't imagine that it was this big," he recalled. "It just looked so complicated, that there was so much to it that I'd never understand it, never get it."

About 170 engineers and technicians work at the launch pad to ready a shuttle for liftoff, along with a few dozen more specialists who come and go during the 30-day preparation period at the pad. Those preparations range from the broad tasks of connecting hundreds of wires and cables when the shuttle stack rolls to the pad to the delicate work of moving multi-ton payloads inches at a time into the cargo bay.

"You can't know it all," Panik said. "There's some 50, 75 different systems. You've got to realize you can't know it all."

The crews who work on the launch pad are affectionately called "pad rats" and they average between 16 and 17 years of experience, Sutherland said. Their specialties rang from handling extremely toxic chemicals to tying down metal platforms, rails and equipment with rope to prevent it from accidentally impacting the spacecraft. The team also is cross-trained in a number of specialties. Sutherland said it takes about two years to get comfortable with a system.

"I have a high level of confidence in their expertise," Sutherland said. "We're very comfortable with what we do."

Shuttles lifted off two pads during the 30 years of the program, Launch Complex 39A and Launch Complex 39B, or just "pad A" and "pad B" to those who worked on them. Built for the Apollo/Saturn V combination, the pads were identical and each had its own work force during most of the shuttle years. Though shuttles occasionally were on both pads together, the practical benefit of having two pads was to let one be refurbished while launches took place on the other.
A crawler-transporter moves the shuttle stack, mounted on a mobile launcher platform, or MLP, the three miles from the Vehicle Assembly Building to pad A, three-and-a-half miles to pad B. The MLP is anchored to steel columns on the pad surface and connected to the rest of the pad complex.

The MLP holds the shuttle stack with eight bolts that are blown apart at the same time the boosters ignite to allow the shuttle to soar into space.

Also, a pair of connection masts on either side of the shuttle's aft compartment is housed on the MLP. The masts contain a battery of wires, cables and the lines that run propellants into the external tank. At launch, the connectors pull back from the shuttle into the masts where armored doors close over them to protect them from the blast.
The pads are considered by some the most advanced in the world, although straight comparisons are difficult because a pad's structure is a direct reflection of the spacecraft it is hosting. A space shuttle, with its reusable engines, delta wings and 60-foot-long cargo bay, has significantly different needs than a capsule.

"I know that what we do out here is a lot more complicated in that we do the final flight processing, all the propellants are loaded out here," Sutherland said. "The hypergolics are loaded at the pad. I know that at other launch facilities those type tasks are done prior to arrival on the launch pad."

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