Shuttle Foam Loss Linked to EPA Regs

As recently as last month, NASA had been warned that foam insulation on the space shuttle's external fuel tank could sheer off as it did in the 2003 Columbia disaster - a problem that has plagued space shuttle flights since NASA switched to a non-Freon-based type of foam insulation to comply with Clinton Administration Environmental Protection Agency regulations.

"Despite exhaustive work and considerable progress over the past 2-1/2 years, NASA has been unable to eliminate the possibility of dangerous pieces of foam and ice from breaking off the external fuel tank and striking the shuttle at liftoff," the agency's Return-to-Flight Task Force said just last month, according to the Associated Press. But instead of returning the much safer, politically incorrect, Freon-based foam for Discovery's launch, the space agency tinkered with the application process, changing "the way the foam was applied to reduce the size and number of air pockets," according to Newsday.

"NASA chose to stick with non-Freon-based foam insulation on the booster rockets, despite evidence that this type of foam causes up to 11 times as much damage to thermal tiles as the older, freon-based foam," warned space expert Robert Garmong just nine months ago.

In fact, though NASA never acknowledged that its environmentally friendly, more brittle foam had anything to do with the foam sheering problem, the link had been well documented within weeks of the Columbia disaster.

"NASA engineers have known for at least five years that insulating foam could peel off the space shuttle's external fuel tanks and damage the vital heat-protecting tiles that the space agency says were the likely 'root cause' of Saturday's shuttle disaster."

In a 1997 report, NASA mechanical systems engineer Greg Katnik "noted that the 1997 mission, STS-87, was the first to use a new method of 'foaming' the tanks, one designed to address NASA's goal of using environmentally friendly products. The shift came as the U.S. Environmental Protection Agency was ordering many industries to phase out the use of Freon, an aerosol propellant linked to ozone depletion and global warming," the Inquirer said.

Before the environmentally friendly new insulation was used, about 40 of the spacecraft's 26,000 ceramic tiles would sustain damage in missions. However, Katnik reported that NASA engineers found 308 "hits" to Columbia after a 1997 flight.

A "massive material loss on the side of the external tank" caused much of the damage, Katnik wrote in an article in Space Team Online.

He called the damage "significant." One hundred thirty-two hits were bigger than 1 inch in diameter, and some slashes were as long as 15 inches.

"As recently as last September [2002], a retired engineering manager for Lockheed Martin, the contractor that assembles the tanks, told a conference in New Orleans that developing a new foam to meet environmental standards had 'been much more difficult than anticipated,'" the Inquirer said.

The engineer, who helped design the thermal protection system, said that switching from the Freon foam "resulted in unanticipated program impacts, such as foam loss during flight."

The original conceptual design for the shuttle would have had a fly-back booster, probably also burning LOX and H2, although possibly just jet fuel/kerosene and oxygen, which would probably still be more environmentally friendly than the witches brew that comes out of the SRBs. Yet another victim of budget cuts used to benefit the social welfare state.

During the initial stages, I remember a proposal that involved the shuttle riding piggy-back on a jet that would get it to altitude and speed, detach, and return (a lot like Burt Rutan's SpaceShip One concept)

Piggy-back would have been a terrible idea. You're much better off towing the vehicle if possible. Carrying something piggyback generally means the carrying aircraft has to provide the thrust and most of the lift for both itself and the shuttle vehicle. Towing it means you have to have a vehicle that can provide its own lift (the Shuttle is marginal at best in providing lift - its more of a controlled brick), but all you have to do is provide thrust from the mother vehicle. An empty 747 has gobs of extra thrust to provide...

Kelly Space Technology had a demonstrator of this for the Space Launch Initiative, the program which began in 2000 to develop new reusable launch vehicles, but that program appears to be on the backburner as the insane idea of manned mars missions gets more priority. We would have been better off funding the completion of the X-33, which had its problems, but had cost only about as much as 1 shuttle mission when Bush had it cancelled shortly after taking office (to be fair, it was WELL over budget). The aerospike engines were very promising, and the metallic heat shield would have been much, much more resistant to damage and easier to maintain..

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