The final report from the Columbia Accident Investigation Board is due this month, and NASA meanwhile is conducting its own review in preparation for a return to flight. Both are expected to point the finger at a chunk of foam insulation that struck the shuttle's wing during launch. A series of impact tests done at the Southwest Research Institute showed that a piece of foam weighing about 1.7 pounds and moving at 779 feet per second could have dislodged or damaged one of the T-seals that separate the wing's protective carbon panels, allowing super hot gases to seep inside the wing as Columbia reentered Earth's atmosphere on February 1.
THE POPSCI OPINION POLL
Should the shuttle be allowed to fly again without a crew escape
The three remaining shuttles are grounded until NASA can ensure they won't suffer the same fate. But the leading recommended safety fixes—four outlined here—won't come cheap. Even before the accident, NASA estimated it would need to spend almost $8.7 billion on upgrades to keep the shuttles flying until 2020. Now some critics say the money would be better spent on a new, safer vehicle. If the shuttle is scrapped, though, Americans will have to depend on Russia for rides to the International Space Station—or anywhere else in orbit—for at least another seven years.
The insulation foam that struck the shuttle's wing tore off from the "bipod," two attachment points where struts connect the tank to the shuttle orbiter. Three possible fixes: Replace the bipod foam with heaters to melt ice; reduce the foam's thickness; or cover the foam with a metal enclosure
containing a heater.
Following a safety board recommendation to conduct better inspections of the shuttle, NASA has made arrangements with the National Imagery and Mapping Agency to obtain on-orbit images of all future shuttle missions. The extra surveillance, though, will require American spy satellites, such as the KH-11, to take time out from snooping on other targets.
3. On-Orbit Repairs
A robotic arm known as the Remote
Manipulator System could help the crew make remote-
controlled fixes to their vehicle's body in space. Engineers would need to lengthen its arm with a boom extension and attach a custom
"caulk gun." Equipped with a camera, the robotic arm could also be used for inspections.
For years NASA's own Aerospace Safety Advisory Panel has insisted that the agency build a crew escape system. In one scheme, each astronaut would ride inside
a personal ejection pod, modeled after those used in the B-58. Alternatively, the shuttle's two pilots would use conventional ejection seats while the other crew would ride
inside a single pod.