• teft@startrek.website
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    11 months ago

    That would lead to different focal lengths not different designs completely. Both optical systems for HST and KH were designed by Perkin Elmer so I’ll stick with my first thought that they would be very similar in capabilities.

    • Pons_Aelius@kbin.social
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      11 months ago

      Did you watch the video?

      The tracking problems Hubble would have imaging the earth surface are a direct guide to what differences the design would be.

          • mkwt@lemmy.world
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            11 months ago

            And the angular momentum is conserved.

            Your choices are basically RCS thrusters or reaction wheels. Thrusters burn limited fuel. Reaction wheels are flywheels inside the satellite that you spin in the operator opposite direction to where you want to rotate. They are limited by the mass and size of flywheel, and the maximum speed you can spin it up to.

            • yetiftw@lemmy.world
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              11 months ago

              electromagnets also work as the earth has a magnetic field. a pair of reaction wheels can be rotated (which yes, adds complexity) opposite directions along an axis perpendicular to the axles once they have reached saturation, effectively resetting the reaction wheels

      • teft@startrek.website
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        11 months ago

        Did you finish the video where they essentially say what I said in my first comment? Hubble and spy satellites share a lot of the same technologies. I wasn’t aware of the speed issue but other than that they are similar like I said.