New Pad for the Space Shuttle

By Anastasia Toutexis

Slick Six may be the most sophisticated military complex ever built

To the ancient Chumash Indians of California, Point Arguello was holy territory, a land where the fog that drifted in from the Pacific mixed with sacred spirits in the skies. The men and women who swarm over that windswept ground today are still concerned with the heavens, but for a different reason: they are turning part of that area northwest of Los Angeles into the space age's newest launching site, the second center of the U.S. shuttle program. The scheduled first flight: October 1985.

Under construction since 1979 and now nearly four-fifths complete, the Vandenberg Air Force Base Space Launch Complex (SLC 6),* dubbed "Slick Six," is a prodigious arrangement of lofty mobile towers and gaping tunnels, rugged bunkers and squat tanks, covering 150 acres.

By March 1985, when Slick Six is expected to be finished, some 250,000 cu. yds. of concrete will have been placed. The estimated cost of construction: $570 million. That, however, represents just a fraction of the budget. Equipping the center with the latest computers and gadgetry will run another $2 billion. But size and expense are not what makes Slick Six unique. Says Air Force Colonel Walter Yager, commander of the Shuttle Activation Task Force: "There have been larger and more expensive projects, but I doubt if there have been any more complicated."

Vandenberg Air Force Base was chosen as a shuttle facility because it offers ideal conditions for launching spacecraft into polar orbit. Shuttles lifting off from Kennedy Space Center in Florida enter a more or less equatorial orbit and fly over only part of the earth's surface. Spacecraft sent from Vandenberg into polar orbit will slice across the earth's twirling path and pass over a slightly different strip of the globe on each swing. Satellites placed in polar orbit have the capability of photographing any section of the earth. This gives them an intelligence-gathering potential significantly greater than the Kennedy-launched space vehicles.

The Air Force, which will operate Slick Six, plans to fly up to ten missions annually. Another point in Vandenberg's favor: shuttles will be launched due south and will fly over Antarctica as well as vast stretches of water, regions where the craft's solid-fuel rocket boosters and external tank can be safely jettisoned.

Until 1969, Vandenberg was the planned launch site for the Manned Orbiting Laboratory (MOL). Congress canceled the construction of the launch pad when it was months away from completion. After the shuttle launch complex was approved and funded, the Air Force figured that it could save $100 million to $300 million by converting the MOL site rather than building from scratch. In fact, the most imposing structure at Slick Six, the 285-ft.-high Mobile Service Tower, is a refitted and slightly shortened version of a MOL facility. The Air Force also cannibalized the steel used in that structure, constructing an access tower for astronauts entering the shuttle.

Building on the MOL's graveyard also forced some curious adjustments. One example: a concrete box filled with dirt had been constructed as a protective blast wall for the orbiting-lab project. Nicknamed the Flower Pot, the box sat directly in the path of the guy wires that a shuttle crew would have to slide down during an emergency evacuation of their craft. To prevent any astronauts from slamming into the now useless structure in the future, the Air Force plans to rip down one corner of the Flower Pot.

Other existing facilities have undergone modifications. The Vandenberg runway was only 8,000 ft. long and paved with asphalt. To make it shuttleworthy, the runway was stretched to 15,000 ft. and paved with concrete. Noting that NASA shuttle facilities at Cape Canaveral were also adapted from earlier, more primitive structures, Colonel Yager declares: "We are both victims of prior history."

If the new shuttle installation has one flaw, it is the inconvenient, 16-mile distance between its landing strip and its launch site. The separation was unavoidable because the blast-off station had to be at seaside, but there was no way to shoehorn a landing runway into the area, which is rimmed on three sides by the Santa Ynez mountains. As a result, a returning orbiter, after its arrival at the runway in the northern part of the Vandenberg base, must be loaded aboard a 76-wheel trailer and towed at a poky 3 to 4 m.p.h. to the launch pad.

To prepare for a launch, technicians at Slick Six will literally put things in motion, that is, move some of the buildings on the site. Three of the eight gigantic structures are mobile. They can be driven under their own power along railroad-style tracks to meet at the launch pad. The first of these traveling skyscrapers is the 27-story-high, 8,000-ton service tower. Moving at a maximum speed of 40 ft. per minute, it travels about 450 ft. to the pad from its customary vantage spot and is locked into place. A 200-ton-capacity crane in the tower's protruding roof then lifts six solid-fuel rocket booster segments from the bed of the rubber-wheeled transporter and sets them on the launch mount. Initial testing of the tower was Jiampered by glitches. Recalls Georg O'Gorman, supervising engineer at the site and unofficial mayor of Slick Six: "There is always a lot of sandblasting going on, and someone missed a few particles. It's like the old wives' tale about the locomotive that couldn't start moving because of a penny under its wheel. The sand did pretty much the same to the tower."

The system now operates with monotonous smoothness. Says Colonel Yager: "From inside you don't even know you're moving. The operator just sits there with his little joy stick. In fact, we're considering a change in the procedure to provide him with a television. It won't change the way the building moves, but it would enhance his perception."

The service tower will neatly unite with the Shuttle Assembly Building, a structure that will be 250 ft. high and weigh 3,000 tons when it reaches completion in late 1984. Approaching the launch pad from a direction opposite to the service tower, it will neatly "mate," as the engineers like to put it, with the other building to form an enclosed, weather-protected space where the rest of the shuttle vehicle can be assembled. Like the tower, the assembly building will have a crane in its roof. Together the two machines can hoist the empty, 154.4-ft.-long, 69,000-lb. external tank of a future shuttle into place between the stacks of rocket boosters. Clearance on each side: less than 1/4 in. The final element in the assembly, the main body of the shuttle, or orbiter, is mounted on the external tank by means of a double crane.

The Shuttle Assembly Building was not part of the original design of the Vandenberg launch pad. Early plans called for vehicle assembly to take place in the semienclosed environment of the service tower, with the tower's crane and a second device, called a strongback, attached to the Launch Mount Tower, to perform all the hoisting. The system called for a tolerance limit of as much as 1/4 in. in fitting the orbiter to the tank. NASA said no, setting the maximum permissible degree of variation at a minuscule ^3^1/iooo^3^1/^1-o-o-o in. "With the wind and the weather at Slick Six, we knew we could never get it down to that," says Major Ronald L. Peck, Vandenberg's chief of public affairs. "So they went back to the drawing boards and came up with the Shuttle Assembly Building. We call it our $40 million one-sixteenth of an inch."

That expensive steel-and-sheet-metal postscript, the assembly building, shelters the newly assembled spacecraft until it is ready for loading. The job begins in a hulking concrete structure called the Payload Preparation Center, a stationary, 147-ft-high building. There, in a relatively particle-free chamber, the spy satellites and other exotic space gear to be carried aloft will be given final checks in sealed chambers. Explains Engineer O'Gorman: "If we do the job right you should be able to take a transistor radio in there and not pick up a single outside signal." This feature is designed to prevent accidental interference during testing and, obviously, to prevent unauthorized monitoring of electronic transmissions.

Unlike the cargo on current flights, Vandenberg payloads such as meteorological and navigational satellites will not have to be placed in bulky canisters to keep them free of contamination. Instead the devices will be taken into the Payload Changeout Room, Slick Six's third movable building. This 158-ft.-high, 6,000-ton structure moves by rail toward the waiting assembly building, where a mammoth door of six panels, each measuring 30 ft. high and 130 ft. wide, will slowly rise, just like a garage door. Inside the building-within-a-building, the payload will be lifted into the orbiter's cargo bay and secured in niches that are custom designed for each piece of space baggage.

The final distinctive features of the launch pad are three massive flame ducts, each 50 ft. high and 70 ft. wide, that will vent the tremendous energy released during lift-offs. Seven seconds before takeoff, an underground pipe 10 ft. in diameter will flood the ducts in less than 30 seconds with about half a million gallons of water. The water will be stored in two tanks. The 6,000DEG F heat produced by the shuttle will be tamed by the liquid, generating huge billows of steam from the ducts during and after the launch. At Cape Canaveral, the vents are lined with firebrick; at Vandenberg, they are made from approximately 130,000 cu. yds. of solid concrete. A special vacuuming process was applied to the concrete while it was setting. This sucked out air and moisture quickly, resulting in a nonporous surface that will better resist cracking during blastoff.

Slick Six's inaugural launch in October 1985 will employ the newest shuttle, Discovery, now being checked out at Cape Canaveral. The exact mission will be top secret, as will all shuttle flights from Air Force-run Vandenberg, but it has been reported that the main job on that first flight will be to ferry two satellites into space. Since Discovery will be placed in a polar orbit, its ground track will cover the Soviet Union. One of those satellites could be a new hush-hush communications package, and the other a device equipped with infrared sensors to spot Soviet missile launches. --ByAnastasia Toufexis. Reported by William R. Doerner/Vandenberg Air Force Base

*"Vandenberg has also been the takeoff point for such missiles as the Minuteman and Trident. SLC 6 will be the sixth active launch pad at the base.

With reporting by William R. Doemer