Wednesday, October 9, 2019

There was a beryllium sphere floating in fluorocarbon at the middle of the MX missile?

Via Tyler Rogoway, this fascinating bit of information about the inertial navigation system of the Peacekeeper missile, called the Advanced Inertial Reference Sphere:
At the heart of Peacekeeper’s guidance and navigation system is the Advanced Inertial Reference Sphere (AIRS) with its highly advanced Inertial Measurement Unit (IMU).  A “beryllium ball” weighing 450 pounds, the AIRS assemblage was designed for exquisite accuracy and, in keeping with that, great resistance to stress and temperature changes. 
Unlike Minuteman III’s gimbal-mounted, metal-touching-metal gyroscopes and accelerometers, those of Peacekeeper’s AIRS are snugly suspended in a highly viscous fluorocarbon liquid, which gives them free play but shields them against environmental fluctuations and keeps them from being bumped around.  AIRS’s beryllium housing is also virtually impervious to the drastic changes of temperature that a ballistic missile undergoes in flight.
I wonder what kind of fluorocarbon was used? (are they viscous?) 


  1. We used to make (many years ago) what was called Fluorolube, which was used for some military applications. These were flourinated telomers that could be adjusted to varying degrees of viscosity. We still have some samples here, some are quite viscous. We still use the less viscous oils for nitrogen bubblers.

    1. Blast from the past! Fluorolube and Nujol, used as mulls for IR spectoscopy.

  2. To Be or not to BeOctober 9, 2019 at 1:09 PM

    Just pointing out that a beryllium sphere was the fuel source for the spaceship in galaxy quest. Coincidence? I think not.


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