I try learn something new every day. Or every other day. Or something like that.
Today I learned that they use water to damp the acoustical waves coming off of the rockets so that the energy in the wave is reduced and doesn’t destroy other equipment. Low frequency waves carry lots of energy. NASA is studying how to control the acoustical energy.
“If you’ve seen launches at the Kennedy Space Center in Florida, then you may have noticed the thousands of gallons of water poured onto the launch pad just before ignition,” said Janice Houston, a launch vehicle acoustics engineer with the Marshall Center’s Propulsion Systems Department. “All this water doesn’t just cool things off as the engines ignite. The primary purpose of the deluge is to help dampen the massive sound waves generated by the rocket.”
Test conductors at Marshall will listen for low- and high- frequency sound waves, as they can both potentially harm the rocket during ascent if not addressed. Low frequency pressure waves can physically impact the vehicle and affect the health of the crew. High frequencies could hurt the smaller, more complex components within the vehicle. Studying these sound waves help engineers redesign the suppression system for a safe launch.