Science: Safety Man

A V-2 rocket which rose last week from White Sands Proving Ground, N. Mex., reached an altitude of 95 miles. The most important man in the act, at least to innocent bystanders, was Herbert L. Karsch, flight safety officer. Karsch’s job is to keep rockets from leaving the 90-by-35-mile area of uninhabited desert and mountains where they are supposed to hit. The authorities would consider it unfortunate, for instance, if a wandering rocket were to smack El Paso.

Like most safety directors, Karsch owes his job to a “regrettable incident.” On May 15, 1947, when White Sands was young, a German V-2 swooped down at 3,500 m.p.h. and landed three miles from Alamogordo (pop. 5,000). Alamogordans had been hardened by years of practice-bombing and an atom-bomb explosion. One woman called up the Army to “get that thing out of my backyard.”

But only a fortnight later, a V-2 went wild internationally. It hit four miles from the center of Ciudad Juarez, Mexico (pop. 48,881), made a fearful bang and dug a crater 24 feet deep and 40 feet in diameter. No one was hurt, and the people of Juarez, enjoying their spring fiesta, thought the bang was part of the show. But the diplomatic repercussions were painful. The White Sands brass, covered with cold sweat, told Karsch to work out a system for riding herd on rockets.

Safety Screen. All sorts of things can go wrong with a rocket. It rises almost vertically at first, and is put on its course by pre-set gyroscopic instruments. When the instruments do not work just right, the rocket may dive to the ground, fly horizontally, or circle back with blood in its eye toward the launching platform. At least six of White Sands’s rockets have circled. One missed the control blockhouse by only about 600 feet.

Karsch is more worried about the rockets that pick nearly right courses which would carry them far outside the target area. To deal with them, he has set up a system he calls a “safety screen.”

Two observers watch the rocket with telescopes. One station notes the east-west component in the rocket’s course; the other the north-south component. Set up in front of each telescope is a “sky screen” with curved lines on it. If the rocket crosses one of these lines, it is likely to fly out of bounds.

When Karsch learns that a rocket is heading out of bounds, he can send up a radio signal that cuts off the rocket’s flow of fuel. This is usually enough to bring it down in a safe area. For really bad cases of rocket misbehavior, there is stronger medicine: he sends up a different signal and blows off the rocket’s nose, which may force it to land near by at low velocity.

Watchful Brain. Karsch’s simple safety screen has worked well, but recently he got a better gadget: an “Impact Predictor,” which can tell in advance just where each rocket will hit. Two observers track the rocket with telescopes. The information from the stations is fed automatically into an electronic brain (analogue computer) which can solve complicated equations almost instantaneously.

Through its two telescopic eyes, the brain watches the rocket. Out of the brain flow figures which show accurately where the rocket will hit. Safety Director Karsch watches these figures. If they should coincide, for instance, with the position of Albuquerque, he could cut off the fuel, change the course of the rocket, and save that unsuspecting city.