In the high-stakes world of human spaceflight, the word "crack" strikes fear into the hearts of engineers. A crack in the reinforced carbon-carbon (RCC) panels of a Space Shuttle’s wing leading edge—exactly what doomed Columbia in 2003—is a catastrophic threat. Yet, in the summer of 2007, NASA celebrated a peculiar triumph:
In 2007, for the first time, astronauts used a hand-held backscatter imager during a spacewalk. This device could: space shuttle mission 2007 crack free