February 2, 2003

Gregg Easterbrook argues that the space shuttles are too old, too large, too complex and too unsafe and should never fly again. He suggests using unmanned rockets when possible and reserving the use of a smaller space plane for missions those truly needing to be manned. Update: Easterbrook wrote a similar article in 1980, arguing that the shuttle was dangerous. One item mentioned was the solid fuel rocket boosters, which would later cause the loss of the Challenger in 1986 (via Kausfiles). Easterbrook talks about the tiles and the external tank’s insulation. The main cause of delay is currently the shuttle's refractory tiles, which disperse the heat of reentry from the ship's nose and fuselage. Columbia must be fitted out with 33,000 of these tiles, each to be applied individually, each unique in shape. The inch-thick tiles, made of pyrolized carbon, are amazing in two respects. They can be several hundred degrees hot on one side while remaining cool to the touch on the other. They do not boil away like the ablative heat shieldings of capsules and modules; they can be used indefinitely. But they're also a bit of a letdown in another respect-they're so fragile you can hardly touch them without shattering them. "The tiles are the long pole holding up the tent," says Mike Malkin, NASA's shuttle project director. Fixing them to the Columbia without breaking them is like trying to eat a bar of Bonomo Turkish Taffy without cracking it. Most of the technicians swarming over Columbia are trying to glue down tiles. The tiles break so often, and must be remolded so painstakingly, the installation rate is currently one tile per technician per week. All this mounting was supposed to be finished before Columbia left Rockwell's factory. When it wasn't, the work had to be resumed at the Cape. "We've had to put up what amounts to a manufacturing facility there," says Walter Kapryan, who retired as the Cape's shuttle project director last spring. "The most we ever did for Apollo was a little patch-wiring." NASA sources privately acknowledge that Columbia was taken to the Cape in unfinished condition partly for public-relations value-to make it appear that preparations were accelerating. The . move also allows computer testing to proceed while the tiles are being mounted. This exercise may have been practical, but it was staggering in cost: $50 million extra to attach the tiles at the Cape, according to congressional sources. Some suspect the tile mounting is the least of Columbia's difficulties. "I don't think anybody appreciates the depths of the problems," Kapryan says. The tiles are the most important system NASA has ever designed as "safe life." That means there is no back-up for them. If they fail, the shuttle burns on reentry. If enough fall off, the shuttle may become unstable during landing, and thus un-pilotable. The worry runs deep enough that NASA investigated installing a crane assembly in Columbia so the crew could inspect and repair damaged tiles in space. (Verdict: Can't be done. You can hardly do it on the ground.) [..] The external fuel tank, for instance, is full of oxygen and hydrogen cooled to -400ƒ F. to make the gases flow as liquids. Ice will form on the tank. When Columbia's tiles started popping off in a stiff breeze, it occurred to engineers that ice chunks from the tank would crash into the tiles during the sonic chaos of launch: Goodbye, Columbia. So insulation was added to the tank. 11:54:42 PM