7 ms·

Based on what, your gut feel? 12 launches per hour does not seem insane at all.

ClumsyPilot 5y ago
Based on the fact that it would be more flying mass than the domestic airline industry.
vanattab 5y ago
In 2020 there was 114 orbital launches supporting all space missions around the world. That's 0.013 launches per hour. 12 launches per hour to support a single mission does not seem at least a little insane? I love SpaceX and am hopeful for their Mars plans but we are scientists and engineers let's think with our brains and not our hearts.
- gremloni 5y ago
  Think about what you’re saying, does 12 launches per hour sound all that crazy? Maybe having 1000s of planes up in the air at the same time would have sounded similarly crazy to someone on the 50s
- brianwawok 5y ago
  if computers taught me anything.. it's if you can do 1 thing really really well perfectly, it's not a ton of work to do it 10x or 100x in parallel. We don't have enough data to know reliability of say Falcon long term. Is it 99% successful? 99.9%? 99.999999%? Doing a ton of launches, you really want to work on the 9s, so 0-1 of your launches blow up, not 100+. But once you do, you just copy paste it baby and go to town.
  - vanattab 5y ago
    I am not convinced the scalability of cyberspace applies to actual space.
    - AnimalMuppet 5y ago
      I don't think it's a good example either. But the scalability of mass production may apply, and that might be good enough...
  - snowwrestler 5y ago
    There is a literally a book called “The Mythical Man Month” about the limits of parallelism in computer engineering. It’s arguably one of the fundamental texts of the discipline.
    - brianwawok 5y ago
      Right. I didn't say we hire 100 developers to code the project 100x faster. I said let's build 100 parallel rocket pads with 100 parallel rockets. It will indeed launch rockets 100x faster. The term you are looking for is embarrassingly parallel.
      - snowwrestler 5y ago
        Only parts of the system are embarrassingly parallel. But you need the whole system to be available for every launch. Poorly parallel parts of the system include regulatory clearance and accident investigations. There is only so much clear air space available each day. And if a rocket blows up (which they often do), they’ll all sit on the ground until there is understanding as to why. And then potentially sit even longer if they each require work to correct or mitigate flaws that are found. Starships are still hand-built prototypes. And Musk has a history of underestimating the difficulty in scaling and automating physical manufacturing. It’s way too early to be confident this can embarrassingly parallel. Parallelism is hard in general. It’s hard because often constraints aren’t obvious until you’re actually doing it.
    - micropresident 5y ago
      And that book has literally nothing to do with what is being discussed.
- meepmorp 5y ago
  What's a few orders of magnitude among friends?
qayxc 5y ago
> Based on what, your gut feel? Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions. The regulatory framework alone is incapable of dealing with that (keep in mind that every orbital rocket is basically an ICBM), let alone the fact that you'd have to spread launches over multiple sites therefore rendering considerable patches of air- and waterways completely closed up for weeks on end. And that's just the regulatory side of things. There's also the logistical side wherein you'd have to consider methane production and -storage as well as ground operations. 100t-class orbital rockets aren't aeroplanes and the procedures involved in checking, refuelling and launch are much more involved. Keep in mind that SpaceX of all companies was the first company who managed to lose a rocket during fuelling in over 5 decades. Now scale that risk (of currently 1:129 - make that 1:1000 since I'm being generous here) to 9,000 launches and you'd be looking at about 9 major explosions (worst case) per launch campaign and that's without the added stress from an unprecedented launch cadence taken into account. You'd be looking at this: https://youtu.be/AOFVuAmcoCA?t=43 https://youtu.be/AOFVuAmcoCA?t=43 two times a week and handwaving that away by quoting fantasy goals for the achievable reliability isn't going to change the fact that even one such incident would halt the entire program for a considerable amount of time.
- Dylan16807 5y ago
  > Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions. So set up a [semi]-permanent airspace restriction somewhere inland, remote enough that there are no local roads to worry about, and don't block any patches of sea. And do the permission in bulk, obviously. > major explosions (worst case) per launch campaign Failure rate is something to consider in several ways but largely unrelated to the launches-per-hour metric.
  - garmaine 5y ago
    It can’t be inland, because there’d be a huge stretch of flyover restrictions. It’d be at sea on top of mobile floating platforms. Like the two oil rigs SpaceX bought last year…

Based on the fact that it would be more flying mass than the domestic airline industry.

In 2020 there was 114 orbital launches supporting all space missions around the world. That's 0.013 launches per hour. 12 launches per hour to support a single mission does not seem at least a little insane? I love SpaceX and am hopeful for their Mars plans but we are scientists and engineers let's think with our brains and not our hearts.

gremloni 5y ago
Think about what you’re saying, does 12 launches per hour sound all that crazy? Maybe having 1000s of planes up in the air at the same time would have sounded similarly crazy to someone on the 50s
brianwawok 5y ago
if computers taught me anything.. it's if you can do 1 thing really really well perfectly, it's not a ton of work to do it 10x or 100x in parallel. We don't have enough data to know reliability of say Falcon long term. Is it 99% successful? 99.9%? 99.999999%? Doing a ton of launches, you really want to work on the 9s, so 0-1 of your launches blow up, not 100+. But once you do, you just copy paste it baby and go to town.
- vanattab 5y ago
  I am not convinced the scalability of cyberspace applies to actual space.
  - AnimalMuppet 5y ago
    I don't think it's a good example either. But the scalability of mass production may apply, and that might be good enough...
- snowwrestler 5y ago
  There is a literally a book called “The Mythical Man Month” about the limits of parallelism in computer engineering. It’s arguably one of the fundamental texts of the discipline.
  - brianwawok 5y ago
    Right. I didn't say we hire 100 developers to code the project 100x faster. I said let's build 100 parallel rocket pads with 100 parallel rockets. It will indeed launch rockets 100x faster. The term you are looking for is embarrassingly parallel.
    - snowwrestler 5y ago
      Only parts of the system are embarrassingly parallel. But you need the whole system to be available for every launch. Poorly parallel parts of the system include regulatory clearance and accident investigations. There is only so much clear air space available each day. And if a rocket blows up (which they often do), they’ll all sit on the ground until there is understanding as to why. And then potentially sit even longer if they each require work to correct or mitigate flaws that are found. Starships are still hand-built prototypes. And Musk has a history of underestimating the difficulty in scaling and automating physical manufacturing. It’s way too early to be confident this can embarrassingly parallel. Parallelism is hard in general. It’s hard because often constraints aren’t obvious until you’re actually doing it.
  - micropresident 5y ago
    And that book has literally nothing to do with what is being discussed.
meepmorp 5y ago
What's a few orders of magnitude among friends?

qayxc 5y ago

> Based on what, your gut feel? Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions. The regulatory framework alone is incapable of dealing with that (keep in mind that every orbital rocket is basically an ICBM), let alone the fact that you'd have to spread launches over multiple sites therefore rendering considerable patches of air- and waterways completely closed up for weeks on end. And that's just the regulatory side of things. There's also the logistical side wherein you'd have to consider methane production and -storage as well as ground operations. 100t-class orbital rockets aren't aeroplanes and the procedures involved in checking, refuelling and launch are much more involved. Keep in mind that SpaceX of all companies was the first company who managed to lose a rocket during fuelling in over 5 decades. Now scale that risk (of currently 1:129 - make that 1:1000 since I'm being generous here) to 9,000 launches and you'd be looking at about 9 major explosions (worst case) per launch campaign and that's without the added stress from an unprecedented launch cadence taken into account. You'd be looking at this: https://youtu.be/AOFVuAmcoCA?t=43 https://youtu.be/AOFVuAmcoCA?t=43 two times a week and handwaving that away by quoting fantasy goals for the achievable reliability isn't going to change the fact that even one such incident would halt the entire program for a considerable amount of time.

Dylan16807 5y ago
> Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions. So set up a [semi]-permanent airspace restriction somewhere inland, remote enough that there are no local roads to worry about, and don't block any patches of sea. And do the permission in bulk, obviously. > major explosions (worst case) per launch campaign Failure rate is something to consider in several ways but largely unrelated to the launches-per-hour metric.
- garmaine 5y ago
  It can’t be inland, because there’d be a huge stretch of flyover restrictions. It’d be at sea on top of mobile floating platforms. Like the two oil rigs SpaceX bought last year…