WASHINGTON — Though recent months have been unusually bad ones for National Aeronautics and Space Administration and the Air Force, the "rash" of rocket explosions is really a rash of coverage of rocket explosions. Rockets fail all the time, and have been failing for years.
When a Titan 34D blew itself to fragments over Northern California last August, for example, it barely merited a wire-service blip, to say nothing of the "holy cow!" headline treatment given to the Delta failure on May 2.
Deltas, commonly called "reliable" in news accounts, have blown up or gone haywire 12 times in 178 launchings, for a 7% failure rate. Titan launchings have produced six failures in 136 attempts, a 6% rate. Twenty-six firings of the space shuttle led to one explosion, or 4% failure. Other rockets in the U.S. inventory, including strategic missiles such as Minuteman, blow up between 1% (Thor) and 10% of the time (Atlas).
The elevation of rocket failures to the status of media events has led to considerable speculation about whether NASA is slipping, contractors are snoozing and so forth. Such charges may in fact be true, and if true merit serious action. But the millions of lines written and spoken about rocketry in the wake of Challenger seem to miss the point. Which is: \o7 Rockets cannot be made foolproof. Some will fail.\f7
Looking back it appears fortunate that a shuttle accident didn't happen sooner. Of the 24 missions flown before Challenger, plus one aborted on the pad, there were two main-engine shutdowns; one near-burnthrough of a solid-rocket booster nozzle, and one failure of the first of two solid-rocket-booster seals. This means four of 25 firings (16%) came within seconds of tragedy. Several other flights experienced severe seal degradation or other conditions which, while not threatening to the mission, suggested that if the shuttles were repeatedly reused according to plan failure would eventually occur.
Why should we expect otherwise? A percentage of conventional airplanes fail and crash--as a Boeing 747 did in Japan last year, its tail section flying apart without clear cause. These crashes occur despite the fact that airplanes operate under conditions only a fraction as stressful as spacecraft. Even military aircraft, where cost is no object, sometimes crash under routine peacetime circumstances.
Yet the United States built an incredibly costly space-shuttle program on the premise that the system would never have a fatal failure. Now the Reagan Administration is on the verge of endorsing construction of a $3-billion replacement shuttle--which by the time it is ready to fly will represent a 20-year-old design concept--on the premise that there will never be another failure.
Whenever there occurs a national upset, Washington officialdom feels it must act tough by immediately spending a huge amount of money. Why not act smart instead? The unlikelihood of building a failure-proof rocket means that manned ventures into space should be limited to those situations when people are truly needed. There are such times; just not as many as the manned space lobby would like. Routine satellite launches are definitely not among them.
Most frightening, early plans show the X31 space plane, a NASA-Pentagon project, repeating the shuttle program's central flaw.
Space planes may end up \o7 even bigger \f7 than the shuttle--plus costlier, more complex and again premised on the notion that they can be made immune to failure. This is a budget justifier's illusion for which there is no real world precedent.
Approximately $450 million was awarded to seven defense contractors last month for space plane research, the goal being a vehicle that can take off from a runway, rise into orbit in one piece and return to a runway. Space planes would be propelled by a hypothetical engine called a scramjet, a cross between a jet and a rocket. From an abstract standpoint this is an excellent goal, one that might, at last, deliver what the shuttle promised: low cost access to space. But as now conceived the X31 may be a greater fiasco.
Space-plane problems are:
--Unquestioning adherence to the biggest-is-best philosophy. Some early space-plane design contenders are even bigger than the shuttle and likely to be the most expensive vessels ever built. This means the country will be able to afford only a few. So we are right back into shuttle syndrome: gambling a vast amount of money, precious human lives and a large share of national prestige on even the most mundane mission.