Science: The Young Rocketeers

"It was just sitting there," said Johnny Easley, 16, of San Angelo, Texas, "and all of a sudden it wasn't." Johnny and his friend Billy Hembree, 17, were sent to a hospital last week with minor injuries after trying to fly their do-it-yourself rocket, a 2-ft. copper tube filled with a mixture of zinc dust and sulphur. They lit it and ran. "It was just like the Flopnik [Vanguard]," said Billy, "going great at first. Then it just folded." When they returned to investigate, the rocket exploded. Johnny and Billy were lucky; a few weeks earlier, Science Teacher Garland Foster of the Floydada, Texas high school was killed while demonstrating a somewhat smaller rocket.

All over the U.S., homemade rockets are fizzing, exploding and—on rare occasions—soaring into the sky. Sometimes they fall to earth, their launchers know not where. A San Antonio housewife hanging out her wash heard something swoosh down from above, and a length of pipe buried itself in the earth close to her feet. In Boston the National Fire Protection Association urged that amateur rocketry be prohibited until a strict system of supervision can be established.

Fertilizer & Match Heads. Some states and cities have already taken action, but teen-age rocketeers are hard to discourage. While liquid-fueled rockets are top fashion with amateurs, only a few of them are built. They are too complicated and expensive. But news has got around that respectable rockets can be made out of metal tubing closed at one end and filled with a slow-burning solid fuel.

Many different ingredients can be used, and any intelligent teen-ager can find out what they are. Some of the mixtures, especially those containing chlorates and perchlorates, are extremely dangerous. Instead of burning gradually, they are apt to detonate like dynamite. Another dangerous compound is ammonium nitrate, which is sold as fertilizer. When mixed with certain other things, it is a violent explosive, and even by itself it should be treated with respect. The explosion of two shiploads of it wrecked Texas City in 1947, with a loss of 512 lives.

But no rocket fuel is really safe, even the scraped-off match-head material that is popular with subteen-agers. When the fuel burns, it generates gas inside the rocket. If the gas is allowed to escape too easily, its pressure remains low and it generates too little thrust to get the rocket off the ground. If it is confined too much, its pressure rises too high and makes the rocket explode.

Designing a successful solid-fuel rocket is largely a matter of matching the burning rate of the fuel to the nozzle through which the gases escape. This is not easy for skilled experts. For kids with a collection of pipe fittings, a couple of chemicals and almost no knowledge, correct calculation is almost impossible. Many of their rockets are like the crude pipe-bombs that the Mad Bomber hid in Manhattan movie theaters. Some are much worse. Kids are apparently able to acquire most of the hair-raising chemicals that they have been reading about in books on rockets and space flight.