3 ms·

(2001). I'm curious what has changed in this space since then.

hinkley 2y ago
I believe the test tether someone took up burned itself to a crisp. The magnetic flux it experienced from the earth was much more intense than their math predicted. That’s the last I heard.
- dredmorbius 2y ago
  Do you have any idea which mission that was? Wikipedia has a listing, if that helps: <https://en.wikipedia.org/wiki/Space_tether_missions https://en.wikipedia.org/wiki/Space_tether_missions>
  - throw310822 2y ago
    TSS-1R mission, 1996 "TSS-1R was deployed (over a period of five hours) to 19.7 km (12.2 mi) when the tether broke. The break was attributed to an electrical discharge through a broken place in the insulation." "Measured currents on the tether far exceeded predictions of previous numerical models by up to a factor of three"
    - dredmorbius 2y ago
      Thanks, I seem to remember that vaguely. I've also had the idea for a while (probably inspired by that mission) that any actual space elevator would be hugely influenced by magnetic and electrical influences, becoming a tremendously long conductor and/or static-charge accumulator. You'd probably want it to be exceptionally well grounded, and want to take precautions embarking or disembarking.
    - hinkley 2y ago
      What I was never clear on is whether that makes them more interesting or less realistic.
      - dredmorbius 2y ago
        The one thing that's clear is that this makes tethers a more challenging engineering problem than a naive / uninformed view might have suggested. This is almost always the situation in engineering applications. The simple approach based on first principles turns out to be massively influenced by second- and higher-order effects. See Admiral Hyman Rickover's "Paper Reactors" for a classic take on this: <https://whatisnuclear.com/rickover.html https://whatisnuclear.com/rickover.html>
        hinkley 2y ago
        Reminds me of a futurist I read years ago who was sure super critical water oxidation would solve all of our pollution problems. Ceramics are a “Pick two” material. You can handle heat, pressure or corrosion. SCWO requires all three. Some clever team invented composite ceramics trying to fix the problem, but that was a decade or two ago and still it’s a niche solution used for truly pernicious toxins and that’s about it, so I’m guessing it either didn’t work long term or was made out of unobtanium.
        dredmorbius 2y ago
        What's the role of ceramics in SCWO? My only familiarity with that is a quick skim of the Wikipedia article, though that makes no mention of ceramics.

I believe the test tether someone took up burned itself to a crisp. The magnetic flux it experienced from the earth was much more intense than their math predicted. That’s the last I heard.

dredmorbius 2y ago
Do you have any idea which mission that was? Wikipedia has a listing, if that helps: <https://en.wikipedia.org/wiki/Space_tether_missions https://en.wikipedia.org/wiki/Space_tether_missions>
- throw310822 2y ago
  TSS-1R mission, 1996 "TSS-1R was deployed (over a period of five hours) to 19.7 km (12.2 mi) when the tether broke. The break was attributed to an electrical discharge through a broken place in the insulation." "Measured currents on the tether far exceeded predictions of previous numerical models by up to a factor of three"
  - dredmorbius 2y ago
    Thanks, I seem to remember that vaguely. I've also had the idea for a while (probably inspired by that mission) that any actual space elevator would be hugely influenced by magnetic and electrical influences, becoming a tremendously long conductor and/or static-charge accumulator. You'd probably want it to be exceptionally well grounded, and want to take precautions embarking or disembarking.
  - hinkley 2y ago
    What I was never clear on is whether that makes them more interesting or less realistic.
    - dredmorbius 2y ago
      The one thing that's clear is that this makes tethers a more challenging engineering problem than a naive / uninformed view might have suggested. This is almost always the situation in engineering applications. The simple approach based on first principles turns out to be massively influenced by second- and higher-order effects. See Admiral Hyman Rickover's "Paper Reactors" for a classic take on this: <https://whatisnuclear.com/rickover.html https://whatisnuclear.com/rickover.html>
      - hinkley 2y ago
        Reminds me of a futurist I read years ago who was sure super critical water oxidation would solve all of our pollution problems. Ceramics are a “Pick two” material. You can handle heat, pressure or corrosion. SCWO requires all three. Some clever team invented composite ceramics trying to fix the problem, but that was a decade or two ago and still it’s a niche solution used for truly pernicious toxins and that’s about it, so I’m guessing it either didn’t work long term or was made out of unobtanium.
        dredmorbius 2y ago
        What's the role of ceramics in SCWO? My only familiarity with that is a quick skim of the Wikipedia article, though that makes no mention of ceramics.