A Thought of Wrapping Space Shuttle External Tank with Ceramic Fiber Fishnet Stockings

摘要

The new camera system of the shuttle Discovery on STS-114 that blasted off at10:39am, Tuesday, July 26, 2005, after 906 days of grounding since the Columbiaaccident, has produced high resolution data of foam sheddings. The 0.9 lbspiece from the Protuberance Air Load (PAL) ramp on the LH2 tank is believed tobe comparable in its potential adversities to the $\sim 1.67$ lbs BX-250 foamfrom the $-Y$ bipod ramp that demised shuttle Columbia in 2003. The two knownincidences indicate that protuberant foams, possibly in conjunction with theliquid hydrogen temperature, offer lame targets of the aerodynamic forces.Seven other relatively large divots in the STS-114 external tank foaminsulation have been reported, and foam shedding remains to be a challenge tobe resolved before the next space shuttle launch. The relatively large divotsfrom the newly streamlined foam around the -Y bipod area suggests a potentialnecessity for a new line of resolution. We suggest an option to wrap the insulated external fuel tank with a grid ofhigh temperature resistant ceramic fibers ({\it ceramic fiber fishnetstockings}). Assuming fiducial acreage of $20000 ft^2 $, one inch square cellsingle fiber grid will weigh only $60g$ with fiber cost \$66. Even with1500-fiber-equivalent strength, one inch square cell grid will add only $200lbs$ and "miniscule" \$100,000.