It now is a full two years since the disastrous loss of the space shuttle Challenger. The fleet of shuttles has been grounded; a resumption of their flights still is months away. Valuable spacecraft have sat uselessly on the ground, for want of a lift. Missions to Venus and Jupiter, aimed at exploring these worlds, have missed the infrequent planetary alignments during which they can be launched. The national interest has been damaged severely, while the Soviets have surged to the fore as the leading spacefaring power.
Yet all this is nothing more than chickens coming home to roost. It represents the long-delayed price we are paying for decisions made at the start of the shuttle program, in 1971. Those decisions, made at the White House level, mandated that the nation would try to pursue this effort on the cheap. The word was "design to cost," as the nation's leaders forced the space program into a budgetary straitjacket. The shuttle program was to come in at a peak of $1 billion per year and a total cost of $5.15 billion. Therein lay the seeds of failure.
At the outset, project managers were prevented from using their best judgment as to the proper choice of designs. Instead, everything was sacrificed to the requirements of the budget. One aerospace firm, Grumman, proposed to use existing rocket technology from the Apollo moon-landing program to develop a shuttle booster. The advantages were clear: greater safety, greater reliability, less risk. But this approach would have added all of $200 million to the peak funding, which meant it wasn't good enough. The Grumman proposal was abandoned in favor of the use of solid-propellant boosters, which were cheaper. Fifteen years later, the failure of such a booster destroyed Challenger.
When the program got under way in 1972, the tight budgets forced further compromises. "Success-oriented management" soon became the order of the day. This amounted to institutionalized optimism, with the attitude being: "Most of our designs turned out all right in the Apollo program, so we'll assume that the same will happen this time, too." It meant cutting back on tests and on the purchase of spare parts. It meant picking a single design and a single contractor for such critical items as the shuttle's main engines, rather than reduce the risk by having two or more contractors pursue competing designs. It also meant reliance on the results of paper studies, prepared by other optimists, to guide the program.
The results of this were not long in coming. Beginning in 1974, the main engines--liquid-fueled rockets of a type never before built--experienced a disheartening series of fires in their ground tests. For four years the engineers at Rocketdyne in Canoga Park, builder of these rockets, struggled to come up with new designs that would solve the problems. Meanwhile, the program schedule began to slip. The first flight of the shuttle had originally been set for March 1, 1978. But as late as Christmas of that year, a Rocketdyne main engine experienced still another fire. Not until late 1979 were these rockets qualified for flight.
Meanwhile, Rockwell International was assembling the first shuttle orbiters. These were covered with thermal-protection tiles, blocks of heat-resistant fiber to protect the craft from the searing temperatures of atmosphere entry. But in 1979 it became clear that these tiles had a tendency to come loose and fall off. Intensive efforts solved this problem too, but at a cost: the first flight did not take place until 1981. These delays brought a manager's nightmare--the entire project staff had to be kept on payroll, awaiting a solution to the problem of the tiles--a solution that might have been found years earlier, if there had been more money back then. The resulting cost overruns came to billions of dollars, easily wiping out the savings that were to have been achieved through design-to-cost.
Finally the shuttle was qualified for flight, and from 1981 to 1986 it ran off a string of 25 successful mission. But all along, the worst problem of all was lurking undetected. This problem, the unreliability of the solid-fueled booster rockets, exploded into national attention two years ago.And to this day, amid the huge costs and delays, there still is no guarantee that it has been solved. As a technical issue, the solid-booster problem is very much of a piece with the earlier difficulties with the main engines and the thermal tiles. The difference is that it emerged at a time when the nation had committed its fortunes in space to the success of these boosters.
How can we avoid such a debacle in the future? We should undertake a major technical initiative only if we are convinced that the nation as a whole--not just the sponsoring agency--needs it. Then, the budgets must be set by engineering managers who know the problems, rather than by political leaders eager to achieve short-term cost savings. We should remember that refrigerators and autos can be designed to cost--but not space shuttles. The uncertainties in new technology are too great for anyone to pretend otherwise.