NASA Finalizes Ares 1 Vibration Fix

Space News ^ | 12/22/2009 | Amy Klamper

[ErnstStavroBlofeld]

NASA’s managers have settled on a fix they say will protect astronauts from potentially dangerous levels of vibrations that could otherwise reach the planned Orion Crew Exploration Vehicle during its climb to orbit atop the Ares 1 rocket, according to information posted on a NASA Web site.

NASA Constellation program officials decided Dec. 17 to update the Ares 1 vehicle design to include upper-plane C-spring isolators and an upper-stage liquid oxygen (LOX) damper intended to keep vibrations originating in the Ares 1 main stage from reaching Orion and its crew.

The Constellation program is a 5-year-old effort to replace the space shuttle with new rockets and spacecraft optimized for the Moon, including Orion and the Ares 1 booster. Since 2007, NASA engineers have been looking at options for “detuning” Ares 1 to prevent oscillations originating in its solid-rocket main stage from synching up with the natural resonance of the rest of the vehicle, potentially exposing astronauts to unsafe levels of shaking by the time the vibrations reach the Orion capsule.

Thrust oscillation is common to solid-rocket motors, the casings of which tend to resonate like organ pipes as their propellant burns from the inside out. Rocket designers commonly stiffen joints or make the vehicle heavier to prevent these up-and-down vibrations — or oscillations — from growing stronger as they travel up the length of the rocket.

[Tolsti2]

Great stuff. I’m hopefully that hussein won’t ruin this. Of course he’s surely wheeling and dealing behind the scenes, possibly buying votes on other things. Which sucks, and is the opposite of the ‘open’ discussion of stuff like this. Grrr.

[BallyBill]

[tm61]

except it will be painted white, and cost 20x what it would at Advance Auto

[saganite]

The latest iteration of the Obama plan for NASA kills off Ares.

[GraceG]

>> except it will be painted white, and cost 20x what it would at Advance Auto <<

Not to mention the sweat heart deal some union will get to manufacture this part.

[Screaming_Gerbil]

You need a Vibration Damper that can take the forces and is designed for the frequency range of interest.

Strangely enough, the standard shock absorber isn't exactly a vibration damper. It's designed to extend and in so doing sort of "push down" the tires to keep them making contact with the road (don't want your tires bouncing up and down and not making contact with the road - it's bad for control). If you ever see a car on a "washboard" test pavement the front end of the vehicle will actually raise up as it's going down that section of test road.

http://en.wikipedia.org/wiki/Tuned_mass_damper

Pictures of a couple of interesting vibration dampers I found doing a short look online are shown below: