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I previously said that if the launch works through staging, SpaceX fans would declare it a success. Personally, that seems like a pretty low bar compared to thi

I previously said that if the launch works through staging, SpaceX fans would declare it a success. Personally, that seems like a pretty low bar compared to things like Saturn V and even STS, both of which launched successfully to orbit the first time.

kbenson 3y ago
What you count as success depends on what your goal is. It's entirely possibly SpaceX could have thrown extra billions at it and had a higher chance of successful orbit, but that doesn't mean they deemed that the most efficient use of time and money to advance the project. Sometimes it's far less costly in time and effort to start it up and see where it fails rather than look it over another 20 times and wrack your brain for anything you've missed before. When I think I've gotten pretty far in a program I'm writing and there's even a small chance of it partially functioning, I'll often fire it up to get feedback on the errors I wasn't aware of as early as possible. Some of those may indicate larger structural changes that are required in the worst case, and the earlier I can learn about those the better.
- cratermoon 3y ago
  > What you count as success depends on what your goal is Yes. My point is that the bar seems pretty low for Starship, and it's not clear why. Yes, some of the ways they are doing things are new, but overall, building large multi-stage rockets is 50s tech.
  - dotnet00 3y ago
    The "50s tech" was not based around easily reusable systems. It was all based on explosive bolts, solid fueled ullage motors etc. On top of that the fuel was much easier to work with and did not involve needing to be able to handle pressurization and sloshing during flips. It's 50's tech only in the same way that a Ryzen CPU is 70's tech.
    - cratermoon 3y ago
      Just for a minute, then, let's think like engineers and not Starman Jones. Granted it was a test flight: so what were the objectives of the flight, how man y of them did it achieve, and how many were not? Get beyond calling it a success or failure and talk about what worked and what didn't. > the fuel was much easier to work with This is a technical detail where I hard disagree. The oxidizer was liquid oxygen, so that's the same. The fuels were either RP-1 or hydrogen. Methane is somewhere in between those two in difficulty. kept at -180 °C, compared to -253 °C for hydrogen, and LOX is LOX. In the Saturn V, sloshing of the RP-1 led to the Pogo Effect, but that was solved[1]. Granted it didn't involve the maneuvers of the Starship first stage, but in some ways it was worse, because it happened during full thrust at the end of the boost stage, not after separation. You can read a lot more about NASA's experience with pogo at [2], but it's worth noting that it continued to crop up as late as Apollo 13, when the 2nd stage center engine shut down early as a result. Yes, SpaceX is doing some things new, but the engineering experience is definitely something from the 50s and 60s. 1. https://www.nasa.gov/history/50-years-ago-solving-the-pogo-effect/ https://www.nasa.gov/history/50-years-ago-solving-the-pogo-e...
      - dotnet00 3y ago
        In terms of objectives, the stated primary objective was to get through staging without blowing up. That was a success. The secondary objective was getting to reentry for the Ship - testing the heat shield, which was a failure.
        cratermoon 3y ago
        > the stated primary objective was to get through staging without blowing up. So I was more or less correct at the top of the thread when I said, "if the launch works through staging, SpaceX fans would declare it a success", and I consider that a low bar.
        Aeolun 3y ago
        I think you might build a rocket that was less prone to blowing up, but it might not be as efficient. You might also not be able to build it with a room full of idealistic youths running on inspiration.
  - mr_toad 3y ago
    50s, and even 60s era Rockets were smaller, with fewer engines and didn’t attempt crazy aerobatics while stopping and restarting engines.
merman 3y ago
cratermoon, you strike me as a rocket enthusiast. Take a look at a little-known rocket called "Falcon 9". Had more test failures than most rockets had launches. You can use that to help strengthen your argument that they really don't know what they're doing over there
- cratermoon 3y ago
  Good point. They've been very successful with the Falcon 9. You'd think they have things like structural integrity, boost-back maneuvering, and how not to blow up figured out by now, but apparently SpaceX has different engineers working on Starship. At least the Raptor engine seems to work well. If it doesn't get concrete and rebar in it, and the fuel and oxidizer don't leak from the tanks. Aside from that, I consider the Raptor pretty darn impressive.

kbenson 3y ago

What you count as success depends on what your goal is. It's entirely possibly SpaceX could have thrown extra billions at it and had a higher chance of successful orbit, but that doesn't mean they deemed that the most efficient use of time and money to advance the project. Sometimes it's far less costly in time and effort to start it up and see where it fails rather than look it over another 20 times and wrack your brain for anything you've missed before. When I think I've gotten pretty far in a program I'm writing and there's even a small chance of it partially functioning, I'll often fire it up to get feedback on the errors I wasn't aware of as early as possible. Some of those may indicate larger structural changes that are required in the worst case, and the earlier I can learn about those the better.

cratermoon 3y ago
> What you count as success depends on what your goal is Yes. My point is that the bar seems pretty low for Starship, and it's not clear why. Yes, some of the ways they are doing things are new, but overall, building large multi-stage rockets is 50s tech.
- dotnet00 3y ago
  The "50s tech" was not based around easily reusable systems. It was all based on explosive bolts, solid fueled ullage motors etc. On top of that the fuel was much easier to work with and did not involve needing to be able to handle pressurization and sloshing during flips. It's 50's tech only in the same way that a Ryzen CPU is 70's tech.
  - cratermoon 3y ago
    Just for a minute, then, let's think like engineers and not Starman Jones. Granted it was a test flight: so what were the objectives of the flight, how man y of them did it achieve, and how many were not? Get beyond calling it a success or failure and talk about what worked and what didn't. > the fuel was much easier to work with This is a technical detail where I hard disagree. The oxidizer was liquid oxygen, so that's the same. The fuels were either RP-1 or hydrogen. Methane is somewhere in between those two in difficulty. kept at -180 °C, compared to -253 °C for hydrogen, and LOX is LOX. In the Saturn V, sloshing of the RP-1 led to the Pogo Effect, but that was solved[1]. Granted it didn't involve the maneuvers of the Starship first stage, but in some ways it was worse, because it happened during full thrust at the end of the boost stage, not after separation. You can read a lot more about NASA's experience with pogo at [2], but it's worth noting that it continued to crop up as late as Apollo 13, when the 2nd stage center engine shut down early as a result. Yes, SpaceX is doing some things new, but the engineering experience is definitely something from the 50s and 60s. 1. https://www.nasa.gov/history/50-years-ago-solving-the-pogo-effect/ https://www.nasa.gov/history/50-years-ago-solving-the-pogo-e...
    - dotnet00 3y ago
      In terms of objectives, the stated primary objective was to get through staging without blowing up. That was a success. The secondary objective was getting to reentry for the Ship - testing the heat shield, which was a failure.
      - cratermoon 3y ago
        > the stated primary objective was to get through staging without blowing up. So I was more or less correct at the top of the thread when I said, "if the launch works through staging, SpaceX fans would declare it a success", and I consider that a low bar.
        Aeolun 3y ago
        I think you might build a rocket that was less prone to blowing up, but it might not be as efficient. You might also not be able to build it with a room full of idealistic youths running on inspiration.
- mr_toad 3y ago
  50s, and even 60s era Rockets were smaller, with fewer engines and didn’t attempt crazy aerobatics while stopping and restarting engines.

merman 3y ago

cratermoon, you strike me as a rocket enthusiast. Take a look at a little-known rocket called "Falcon 9". Had more test failures than most rockets had launches. You can use that to help strengthen your argument that they really don't know what they're doing over there

cratermoon 3y ago
Good point. They've been very successful with the Falcon 9. You'd think they have things like structural integrity, boost-back maneuvering, and how not to blow up figured out by now, but apparently SpaceX has different engineers working on Starship. At least the Raptor engine seems to work well. If it doesn't get concrete and rebar in it, and the fuel and oxidizer don't leak from the tanks. Aside from that, I consider the Raptor pretty darn impressive.