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We've had many discussions on HN about SpinLaunch, but Brian real goes through and answers several of the questions that were left unanswered, love it.

jasode 4y ago
I think we can assume Brian McManus read over the past HN thread (April 2022) with the skeptical comments about the feasibility because he puts a screen shot of that thread in the video. Deep link to the HN cameo appearance: https://www.youtube.com/watch?v=yrc632oilWo&t=39m48s https://www.youtube.com/watch?v=yrc632oilWo&t=39m48s
whartung 4y ago
I don't know why this system is such a magnet of internet skepticism. Of course the system is extraordinary, but it's an engineering project. An engineering project with a lot of "knowns", vs "known unknowns". It's mostly a materials science project. It's a complicated integration problem with all of the engineering associated with that, but, to be fair, they're not making up a lot of stuff out of whole cloth, they're utilizing known things in new ways. Simply, much of the concept can be simply tested after the napkin math is performed. Tested to the point of either "yea this will work" vs "no way". As far as I know, there's no real government money in this, they don't seem to be running in to a lot of administrative red tape (like, high speed rail is not an engineering problem, it's social and governance problem). So, doesn't seem to be some swamp land boondoggle. Can it fail? Of course it can fail. Is it inevitable? No, I don't think so. I don't think it's a bill of goods sold to investors to fund a few engineers in the middle of the desert.
- marcosdumay 4y ago
  Any reasonable version of it (what must look very different from the prototype) is an incredibly expensive investment, that must be diluted into what is currently an outrageous number of launches to pay for itself. Besides, there are some very problematic known unknowns involved on submitting things that want to explode to high g. All of it looks patently possible, given enough money and engineer-time. It's the kind of project that may change the relation Humanity has with space, but has huge odds of bankrupting the entity doing it even if it succeeds in reshaping Humanity. So yeah, it's either government built or it won't get built at all.
  - JumpCrisscross 4y ago
    > it's either government built or it won't get built at all This is a false dichotomy. Falcon Heavy is not government built. It nevertheless benefits from American largesse. SpinLaunch is in effect building the world's largest rail gun. If the proof of concept works they won't have trouble lining up grants.
    - marcosdumay 4y ago
      Oh, man. If you think you can get it done in a single billionaire's budget, all power to you. But developing a Falcon Heavy looks like a much smaller marginal project than a launch rail.
      - bobsmooth 4y ago
        I'm sure the US military will be interested in a launch platform that can quickly get a payload into space.
    - Aeolun 4y ago
      There’s always military uses.
- chasil 4y ago
  The video stresses that this has been done before at similar energies, and modern materials can vastly improve reliability and reuse. Project HARP attempted to do this in the 1960s. https://en.m.wikipedia.org/wiki/Project_HARP https://en.m.wikipedia.org/wiki/Project_HARP
- MichaelCollins 4y ago
  > I don't know why this system is such a magnet of internet skepticism. Because even if it works, it's still bonkers. Any proposal that involves extreme engineering never done before is going to illicit a lot of skepticism. And this proposal also catches all the general (often unfounded) skepticism people have regarding space. And it catches the skepticism people have for startups proposing radical new technology. And being a space startup, it catches the skepticism inherent to being Musk-adjacent. Spinlaunch is a perfect storm for raising eyebrows.
  - sjburt 4y ago
    The frustrating thing is that the skepticism always centers on basic physics/engineering problems that clearly have been solved before such a design would break ground. Nobody builds a giant centrifuge and says "Oh I didn't expect such high g forces!" The areas I'm skeptical about are whether customers will be able or willing to design for 10,000G loads, and what market remains once Starlink can bring 120,000 kg to LEO at once. that fits a lot of small satellite ride shares.
    - WalterBright 4y ago
      I'm amazed that radar circuits (for proximity fuses) can be fired out of a flak gun and survive and work, so maybe this is possible.
      - sjburt 4y ago
        The US has had (for several decades) guided artillery shells, both optical and inertially guided. These get launched from battleship cannons and deploy fins to guide them to the target. The inertial guidance is almost more surprising, it means the IMU can not only survive being launched, but has enough sensitivity to double integrate accurately through both the launch and free fall.
    - nsonha 4y ago
      > Nobody builds a giant centrifuge and says "Oh I didn't expect such high g forces!" Nobody build a satellite and expect such high g forces, they don't build satellite to accommodate to launch system, it's the other way around.
- grecy 4y ago
  As Elon said about Starship - "We're not breaking any laws of physics here, so it should work". Sure, it's super expensive and massive, but that doesn't mean it won't work.

jasode 4y ago

I think we can assume Brian McManus read over the past HN thread (April 2022) with the skeptical comments about the feasibility because he puts a screen shot of that thread in the video. Deep link to the HN cameo appearance: https://www.youtube.com/watch?v=yrc632oilWo&t=39m48s https://www.youtube.com/watch?v=yrc632oilWo&t=39m48s

whartung 4y ago

I don't know why this system is such a magnet of internet skepticism. Of course the system is extraordinary, but it's an engineering project. An engineering project with a lot of "knowns", vs "known unknowns". It's mostly a materials science project. It's a complicated integration problem with all of the engineering associated with that, but, to be fair, they're not making up a lot of stuff out of whole cloth, they're utilizing known things in new ways. Simply, much of the concept can be simply tested after the napkin math is performed. Tested to the point of either "yea this will work" vs "no way". As far as I know, there's no real government money in this, they don't seem to be running in to a lot of administrative red tape (like, high speed rail is not an engineering problem, it's social and governance problem). So, doesn't seem to be some swamp land boondoggle. Can it fail? Of course it can fail. Is it inevitable? No, I don't think so. I don't think it's a bill of goods sold to investors to fund a few engineers in the middle of the desert.

marcosdumay 4y ago
Any reasonable version of it (what must look very different from the prototype) is an incredibly expensive investment, that must be diluted into what is currently an outrageous number of launches to pay for itself. Besides, there are some very problematic known unknowns involved on submitting things that want to explode to high g. All of it looks patently possible, given enough money and engineer-time. It's the kind of project that may change the relation Humanity has with space, but has huge odds of bankrupting the entity doing it even if it succeeds in reshaping Humanity. So yeah, it's either government built or it won't get built at all.
- JumpCrisscross 4y ago
  > it's either government built or it won't get built at all This is a false dichotomy. Falcon Heavy is not government built. It nevertheless benefits from American largesse. SpinLaunch is in effect building the world's largest rail gun. If the proof of concept works they won't have trouble lining up grants.
  - marcosdumay 4y ago
    Oh, man. If you think you can get it done in a single billionaire's budget, all power to you. But developing a Falcon Heavy looks like a much smaller marginal project than a launch rail.
    - bobsmooth 4y ago
      I'm sure the US military will be interested in a launch platform that can quickly get a payload into space.
  - Aeolun 4y ago
    There’s always military uses.
chasil 4y ago
The video stresses that this has been done before at similar energies, and modern materials can vastly improve reliability and reuse. Project HARP attempted to do this in the 1960s. https://en.m.wikipedia.org/wiki/Project_HARP https://en.m.wikipedia.org/wiki/Project_HARP
MichaelCollins 4y ago
> I don't know why this system is such a magnet of internet skepticism. Because even if it works, it's still bonkers. Any proposal that involves extreme engineering never done before is going to illicit a lot of skepticism. And this proposal also catches all the general (often unfounded) skepticism people have regarding space. And it catches the skepticism people have for startups proposing radical new technology. And being a space startup, it catches the skepticism inherent to being Musk-adjacent. Spinlaunch is a perfect storm for raising eyebrows.
- sjburt 4y ago
  The frustrating thing is that the skepticism always centers on basic physics/engineering problems that clearly have been solved before such a design would break ground. Nobody builds a giant centrifuge and says "Oh I didn't expect such high g forces!" The areas I'm skeptical about are whether customers will be able or willing to design for 10,000G loads, and what market remains once Starlink can bring 120,000 kg to LEO at once. that fits a lot of small satellite ride shares.
  - WalterBright 4y ago
    I'm amazed that radar circuits (for proximity fuses) can be fired out of a flak gun and survive and work, so maybe this is possible.
    - sjburt 4y ago
      The US has had (for several decades) guided artillery shells, both optical and inertially guided. These get launched from battleship cannons and deploy fins to guide them to the target. The inertial guidance is almost more surprising, it means the IMU can not only survive being launched, but has enough sensitivity to double integrate accurately through both the launch and free fall.
  - nsonha 4y ago
    > Nobody builds a giant centrifuge and says "Oh I didn't expect such high g forces!" Nobody build a satellite and expect such high g forces, they don't build satellite to accommodate to launch system, it's the other way around.
grecy 4y ago
As Elon said about Starship - "We're not breaking any laws of physics here, so it should work". Sure, it's super expensive and massive, but that doesn't mean it won't work.