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"Busted" videos like this are low quality armchair analysis aimed at giving giving the viewer a sense of intellectual superiority. Saying "this solution breaks

"Busted" videos like this are low quality armchair analysis aimed at giving giving the viewer a sense of intellectual superiority. Saying "this solution breaks the laws of physics" can be valid if analysis is done correctly, saying "this problem is hard, and they haven't already solved every single piece of it so their whole business is stupid" is not valid.

belter 4y ago
I agree with you that the video could be more detailed on some of the technical analysis. However it raises enough technical arguments, to justify any approach to SpinLaunch to be done in private and with a very skeptical attitude.
- JacobThreeThree 4y ago
  Presumably NASA, who's paying for test launches, did a more thorough analysis than a YouTuber.
  - belter 4y ago
    Only thing NASA seems to have contracted the company for is for a technology demonstrator, of throwing a small rocket at Mach 2. The article describes it like they are throwing satellites into orbit. In reality even the far fetched plan, is to throw a small rocket into high altitude to save money on the first stage. Then the rocket is what will put the satellite in orbit. I can't find a single reference to this agreement (yet) in any NASA official site. Not saying it's not real, just that I can't find an official NASA reference yet. It's not yet listed here under the current available ongoing agreements: "Current Space Act Agreements" https://www.nasa.gov/partnerships/about.html https://www.nasa.gov/partnerships/about.html
    - attilaperez 4y ago
      Theranos had Walgreens, Nikola had GM...
arein3 4y ago
These types of videos have a very wide audience. Redditors love them.
belter 4y ago
This analysis also highlights the complexity risks. They will need to achieve Mach 10 and have a satellite capable to handle 20,000 G... "Spinlaunch Feasibility Analysis": https://colab.research.google.com/gist/jeff-hemingway/a3d32262964996251554d372dee5de7f/spinlaunch.ipynb https://colab.research.google.com/gist/jeff-hemingway/a3d322... Edit: The HARP project is also mentioned in the analysis as a comparison. https://en.wikipedia.org/wiki/Project_HARP https://en.wikipedia.org/wiki/Project_HARP
- deleted 4y ago
  [deleted]
- Retric 4y ago
  20,000g’s sounds much worse than it is. Some WWII era guns used ammunition with complex proximity fusses subjected to roughly 20,000g’s. The real question is what kind of mass fraction is sacrificed to build something to survive being spun up.
  - JackFr 4y ago
    And they did it without solid state electronics. Literally putting vacuum tubes in artillery shells.
  - jhgb 4y ago
    Here's the thing: If you built something like Quicklaunch instead (https://en.wikipedia.org/wiki/Quicklaunch https://en.wikipedia.org/wiki/Quicklaunch), your g forces would already be an order of magnitude lower. So the question is, why not do that instead?
    - Retric 4y ago
      They could have lowered the g forces by having a longer arm, they essentially picked the g forces as acceptable and then designed the system around that constraint. As to why not use a gun, barrel damage is probably a deal killer for Quicklaunch and other such designs. Quickly spinning something in a vacuum and letting go should allow for launches roughly as fast as you can pull vacuum. Supporting something like a Starlink constellation seems possible with their design which could be incredibly profitable.

belter 4y ago

I agree with you that the video could be more detailed on some of the technical analysis. However it raises enough technical arguments, to justify any approach to SpinLaunch to be done in private and with a very skeptical attitude.

JacobThreeThree 4y ago
Presumably NASA, who's paying for test launches, did a more thorough analysis than a YouTuber.
- belter 4y ago
  Only thing NASA seems to have contracted the company for is for a technology demonstrator, of throwing a small rocket at Mach 2. The article describes it like they are throwing satellites into orbit. In reality even the far fetched plan, is to throw a small rocket into high altitude to save money on the first stage. Then the rocket is what will put the satellite in orbit. I can't find a single reference to this agreement (yet) in any NASA official site. Not saying it's not real, just that I can't find an official NASA reference yet. It's not yet listed here under the current available ongoing agreements: "Current Space Act Agreements" https://www.nasa.gov/partnerships/about.html https://www.nasa.gov/partnerships/about.html
  - attilaperez 4y ago
    Theranos had Walgreens, Nikola had GM...

arein3 4y ago

These types of videos have a very wide audience. Redditors love them.

belter 4y ago

This analysis also highlights the complexity risks. They will need to achieve Mach 10 and have a satellite capable to handle 20,000 G... "Spinlaunch Feasibility Analysis": https://colab.research.google.com/gist/jeff-hemingway/a3d32262964996251554d372dee5de7f/spinlaunch.ipynb https://colab.research.google.com/gist/jeff-hemingway/a3d322... Edit: The HARP project is also mentioned in the analysis as a comparison. https://en.wikipedia.org/wiki/Project_HARP https://en.wikipedia.org/wiki/Project_HARP

deleted 4y ago
[deleted]
Retric 4y ago
20,000g’s sounds much worse than it is. Some WWII era guns used ammunition with complex proximity fusses subjected to roughly 20,000g’s. The real question is what kind of mass fraction is sacrificed to build something to survive being spun up.
- JackFr 4y ago
  And they did it without solid state electronics. Literally putting vacuum tubes in artillery shells.
- jhgb 4y ago
  Here's the thing: If you built something like Quicklaunch instead (https://en.wikipedia.org/wiki/Quicklaunch https://en.wikipedia.org/wiki/Quicklaunch), your g forces would already be an order of magnitude lower. So the question is, why not do that instead?
  - Retric 4y ago
    They could have lowered the g forces by having a longer arm, they essentially picked the g forces as acceptable and then designed the system around that constraint. As to why not use a gun, barrel damage is probably a deal killer for Quicklaunch and other such designs. Quickly spinning something in a vacuum and letting go should allow for launches roughly as fast as you can pull vacuum. Supporting something like a Starlink constellation seems possible with their design which could be incredibly profitable.