Shrink-wrap the external fuel tank. Insulate the tank on the inside rather than the outside to prevent chunks of foam from breaking off and striking the space shuttle, as happened with Columbia.
Cover the edges of the shuttle wings with titanium. Add a second layer of reinforced carbon skin.
These are just a few of the hundreds of suggestions that have streamed into NASA, from both inside the space agency and outside, ever since the first version of its return-to-flight plan came out two months ago.
In the latest update Monday, NASA summarized the suggestions and estimated it will cost $280 million to carry out all the safety recommendations put forth by Columbia accident investigators. But the ultimate cost of getting the three remaining shuttles flying again will almost certainly be higher.
“This is obviously just our best estimate of return-to-flight costs,” said NASA spokesman Allard Beutel.
NASA has yet to figure out how to patch a hole in the wing like the one that brought down Columbia in February, and development of such a repair kit will probably drive costs up.
Some of the suggestions made by NASA employees and members of the public would also run up costs and could keep the shuttle fleet grounded even longer if the proposals require an extensive redesign. Right now, NASA is aiming for a launch no earlier than next fall.
Every suggestion, no matter how silly or outrageous, is being reviewed and getting an individual response, NASA said.
“Even the ones you would characterize as junk or a joke, every one gets reviewed,” Beutel said. “They’re not just blowing them off. They are reviewing every single one.”
Some messages are passed up the NASA chain to avoid relying on a single person’s judgment on “what is kooky and what is not,” Beutel said.
NASA’s embrace of suggestions is in stark contrast to the attitude that prevailed during Columbia’s doomed flight, when engineers’ worries about wing damage were disregarded.
NASA created an electronic mailbox for return-to-flight suggestions on Sept. 8, the day the space agency released its initial plan for implementing safety changes and resuming shuttle launches.
As of Nov. 12, NASA had gotten 286 suggestions, most of them from the public.
Dozens of messages involve highly technical aspects of the spacecraft, while others offer more general advice.
One recurring question is why NASA cannot sell ads on the shuttles. Answer: Because it is a government agency.
As for encasing the external fuel tank in shrink-wrap or netting, engineers say it is a good idea but caution it could make matters worse and cause even more foam shedding. Putting foam insulation on the inside of the tank probably would contaminate the fuel and gum up the main engines. Titanium on the wings’ leading edges would boil away in the heat of re-entry, while a second layer of reinforced carbon skin would be difficult if not impossible to attach without piercing the innermost layer.