i'd be in the cul-de-sac, and we'd all look up, and we could hear those roars. >> in california santa susana mountains rocketdyne engineers had created america's largest prupulgz field laboratory. >> the whole of the valley would just shudder. >> launch is go. >> tens of thousands of rocket tests, and those would produce huge plumes of contamination that would be spreading a substantial distance. >> engines poured forth their pillars of flames. >> over 30,000 rocket engine tests, and a lot of the chemical contamination on the site is a result of that. >> they ended up flushing out rocket test engines with a very toxic solvent called tce, hundreds of thousands of gallons, leaving half a million