Home of Minuteman

If excitement and urgency showed on a map, one of the most conspicuous places in the U.S. this week would be an edge of northern Utah, hitherto noted chiefly for peaches, sheep and sugar beets. This unlikely region, in Box Elder County north of Great Salt Lake, is boiling with frantic activity. Strange lights glare in the night, making the mountains shine, and a grumbling roar rolls across the desert. By day enormous clouds of steam-white smoke billow up in a few seconds and drift over hills and valleys. Monstrous vehicles with curious burdens lumber along the roads. All these strange goings-on mark the development of the Minuteman, the solid-fuel missile that its proponents confidently expect will ultimately replace the liquid-fuel Atlas as the U.S.'s standard ICBM.

No Countdown. It all began in 1957 when the null people of Brigham City heard without much interest that an East Coast outfit with a peculiar name, Thiokol Chemical Corp., planned to build some sort of plant on a nearby desert. Few realized that the newcomer would turn their isolated, sheep-and-sugar-beet town into a booming center of U.S. rocketry. Today the rocket plant's employees number more than 3,000, flood Brigham City's roads with traffic and its schools with children. Ranch-style homes for engineers, chemists, physicists and mathematicians are spreading into the beet fields. This is only a beginning. The Air Force announced that it will soon build at Brigham City a full-scale plant to mass-produce Thiokol's mighty first-stage booster for the Minuteman. Estimated cost: $80 million. To be near the expanded operation, Thiokol's top brass last week were preparing to shut up the rocket headquarters at Huntsville, Ala. and move en masse to Ogden, 20 miles south of Brigham City.

The Brigham City plant began as a research center and pilot plant for production of rocket engines filled with the rubbery solid fuel that was Thiokol's first contribution to rocketry. It has grown into 84 smallish structures scattered over miles of desert, but it still reflects the basic simplicity that is solid fuel's chief advantage over liquid. The liquid-fuel rocket engines that push the Thor and Atlas must be static-tested with their flames shooting downward, which requires massive, well-anchored test stands to resist the upward thrust. Their liquid fuel and oxidizer call for pumps, tanks, valves and tubing. Instruments watch every part of their twisted intestinal tract and report to a thick-walled blockhouse protected from blast and flame. A long countdown is required to make sure that every small detail is in working order.

Fat Cylinder. Thiokol's test stands are hardly more than nicks in the rocky hillsides. They need no elaborate structures or tubing because a solid-fuel booster is little more than a fat, blunt-nosed casing for the fuel it encloses. It lies on its side in a heavy steel cradle and pokes its enormous thrust against a vertical rock face sheathed with concrete. Instruments record vibrations, temperatures and the stress in its metal skin, but human watchers do not shelter in a blockhouse. They watch the tests from open hillsides. "Distance is cheaper," they say, "than concrete and periscopes."

When a "big one" is scheduled for a night test, a honking sound beats for a few minutes over the still desert to warn the unwary. Then privileged watchers inside the fence feel the ground tremble under their feet, see a long, white, incredibly brilliant flame jut horizontally out of the hillside. The show lasts for about one minute and shuts off abruptly. There is no fuss, no dramatic countdown, seldom any delay.

Heat to Cure. The plants that make Minuteman boosters are also reflections of solid-fuel simplicity. There is little machine work; most of the engine's comparatively few parts come prefabricated. Biggest part of the job is filling the casing with fuel, which is a secret liquid plastic compound mixed with crystalline potassium perchlorate to supply oxygen. The mixing is done in a plant that is mostly underground. A crane running on rails sets the empty booster casing upright in a square hole. Then an odd-looking little building mounted on rails moves over each casing and carefully pours it full of paste-thick fuel. When the building rolls to the next hole, the filled casing is covered with sheet metal and heated by pipes set in the hole's walls.

Slowly the fuel is cured to a rubbery solid, tightly filling the casing. When the cure is complete, the booster is lifted out of its hole and carried off for attachment of nozzles and other final items. Then it is stored in an insulated building or truck, and left to cool evenly.

Chief hazards in the filling and curing process are air bubbles or other empty spaces in the fuel. When a solid rocket is fired, the flame starts at a precisely shaped central cavity and eats its way outward. An air bubble allows part of the flame to get ahead of the rest. The result is a "hot spot" that burns a hole in the rocket's metal casing before all its fuel is consumed, causing a disastrous blowout. To eliminate such a mishap, each booster is taken to a fenced-off area blazoned with signs warning against radiation. There it is wrapped in X-ray film, and a speck of fiercely radioactive cobalt 60 is thrust into its cavity. When the films are developed, they show up any air bubbles.

New Monster. The heavy boosters are horsed around by ordinary cranes, but these are being replaced by a monstrous device called a transrector. Built by Hufford Corp. of El Segundo, Calif., it weighs 121,000 Ibs., costs $750,000. With its two engines and its five-man crew, it can lift a booster from deep underground and brandish it like a cigar. Its massive but sensitive arms can pin an egg down so delicately that the shell is not cracked, yet so firmly that the egg cannot be removed without breaking it.

Like all big missiles, Minuteman is an assembly job, using components from many sources. Besides making the heavy first-stage booster, Thiokol may also get the contract for the second-stage booster. The third stage, which has yet to reach final design, will probably be made by Hercules Powder Co. at Bacchus, 15 miles southwest of Salt Lake City. The guidance system, made by North American Aviation, Inc. (it recently got a $115 million contract), will be shipped in from California. Boeing Airplane Co. will put together the three stages and install the guidance system in the completed missile at Hill Air Force Base near Ogden. By 1963, the target date for Minuteman to reach full operational status, this area of dry hills and crags in northern Utah may be the most important missile center in the U.S.

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