• teft@startrek.website
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    1 year 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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      1 year 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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            1 year 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.

            • Madlaine@feddit.de
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              1 year ago

              They have to rotate it fast enough, and hubble is not built to rotate that fast

              • schmidtster@lemmy.world
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                1 year ago

                Is it an actual limitation of the hardware or a software safety limit? The designs are similar it more has to do with limitations put on it.

                They mention they can’t because the gyro vibrates, so it does sound like it’s capable of spinning faster it’s limited for specific reasons. Now are those reasons detrimental to its use or would they just have to get fancier.

                These can’t be answered.

                • Madlaine@feddit.de
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                  1 year ago

                  The sattelite bus for the KH-11 Spy sattelites (which hubble is based on) uses thrusters for orientation (and has a huge propellant tank) while the Hubble sattelite bus uses several gyroscopes for orientation. They are not as similar as you might think.

                  • schmidtster@lemmy.world
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                    1 year ago

                    With reaction wheels/gyros could they not build up momentum over time to achieve the appropriate spin rate to match earths rotation?

                    After that it would just be timing and they could also layer multiple images together to work out details in theory.

      • teft@startrek.website
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        1 year 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.