Within minutes of hearing about the disintegration of the Columbia space shuttle on February 1, management science and engineering department chair Elisabeth Paté-Cornell was in her office, fielding media calls. “I had a pretty good idea about what had happened,” says the risk-analysis specialist who led a 1990 NASA-commissioned study of the shuttle’s insulation tiles. Although it’s “not impossible” that space debris caused catastrophic structural damage, Paté-Cornell says “it could not possibly help to have lost a piece of foam at takeoff and have it hit the tiles.”
As a result of the 100-page report she submitted to NASA in 1990, managers at Florida’s Kennedy Space Center did special testing on zones of tiles that she identified as “most risk-critical”; and she was told that officials at Alabama’s Marshall Space Flight Center reinforced the attachment of the foam insulation on the shuttles’ 15-story external fuel tanks. But Paté-Cornell, MS ’72, PhD ’78, says she was informed that those in charge at Houston’s Johnson Space Center “decided our report was not a reason to add anything or make any modifications” to tile maintenance procedures.
The tiles are likely to be a focus of inquiry for the Columbia Accident Investigation Board, which includes Nobel laureate and physics professor Douglas Osheroff and former astronaut Sally Ride, ’73, MS ’75, PhD ’78 (associate professor of electrical engineering Gregory Kovacs, PhD ’90, MD ’92, is coordinating debris and sensor analyses for the board). In the 22-year-old shuttle’s previous 27 flights, Paté-Cornell says, the tiles had been challenged by vibrations and by aerodynamic forces—but not by “pieces of stuff” like the insulation that fell off and hit the underside of the shuttle’s left wing. The tiles would have held, she adds, “provided they had been well bonded.”
Shuttle flights probably will not be halted for long, because the international space station is still under construction. But in the “medium term,” Paté-Cornell says, “we need a system to replace the shuttle.”
Norman Sleep, who studies solar system origins and planetary habitability, would go a step further. Shortly after the Columbia tragedy, the geophysics professor publicly advocated ending human space flight. “Little science has come out of the manned space program,” he says. “Most of the experiments on [the shuttle] were either ant-farm, science-fair-project-type stuff or things that could have been done completely robotically.” And speaking of robots, Sleep says they’re the ideal space travelers. Not only are they cheaper and unlikely to contaminate moons and planets, he says, but “they don’t need huge amounts of life support, they can be made to do one task very well, and they don’t get sick or bored.”
