4 ms·

The accuracy of MEMS gyros is orders of magnitude worse than the gyros on Hubble. I suspect based on this article [0] that Hubble uses hemispherical resonator g

The accuracy of MEMS gyros is orders of magnitude worse than the gyros on Hubble. I suspect based on this article [0] that Hubble uses hemispherical resonator gyros (HRG [1]). The really high accuracy rate sensors that you find in spacecraft are usually HRGs or Fiber Optic Gyroscopes (FOG). [0] https://science.nasa.gov/mission/hubble/observatory/design/hubble-one-gyro-mode/ https://science.nasa.gov/mission/hubble/observatory/design/h... [1] https://en.wikipedia.org/wiki/Gyroscope#HRG https://en.wikipedia.org/wiki/Gyroscope#HRG

cubefox 2y ago
Oh, this made me worried about JWST (as it can't be serviced once the gyroscopes break), but I found this: > To detect changes in direction JWST uses hemispherical resonator gyroscopes (HRG). HRGs are expected to be more reliable than the gas-bearing gyroscopes that were a reliability issue on Hubble Space Telescope. They cannot point as finely, however, which is overcome by the JWST fine guidance mirror.[18] https://en.wikipedia.org/wiki/Spacecraft_bus_(James_Webb_Space_Telescope) https://en.wikipedia.org/wiki/Spacecraft_bus_(James_Webb_Spa... So Hubble uses gyroscopes that are more precise but less reliable than the HRGs used in JWST.
- dr_orpheus 2y ago
  Interesting, TIL that Hubble uses gas-bearing gyroscopes. I been struggling to find any other spacecraft that use those gas-bearing gyros. The only other one that seems to be using them (that is still operational) is the Chandra X-ray Observatory.