At Marshall Space Flight Center, a relatively simple technology developed to smooth potentially dangerous vibrations in NASA’s defunct Ares I crew launch vehicle is finding its way into the wider world as a way to steady buildings, aircraft, ships and other structures reacting to winds, waves and even earthquakes. The passive approach uses the weight of a liquid coupled to a structure to dampen shaking, swaying, fluttering and other oscillations.
The article says “opponents of a government-owned orbital crew vehicle seized on the thrust-oscillation issue as ammunition in their successful efforts to kill the project”, which I think is misleading. There were a series of judgments made on Ares – SSME changed to a single J-2X, which cut the upper stage thrust by more than half, then adding the fifth segment to the SRB to make up for the loss – that led to the thrust oscillation problem. Having a lower-thrust, lighter-weight upper stage put its natural frequency in the range of the dynamic forces from the booster. It wasn’t “opponents of a government-owned orbital crew vehicle” that killed Ares, because we still have Orion/Multi-Purpose Crew Vehicle work. The killers were problems of their own making, combined with management’s refusal to listen to their technical people, major cost overruns and the WORST preliminary design review I’ve ever seen.
Glad to see something good has come out of it.