8 ms·

> The detonation at the end was pretty spectacular too, but I suspect that structurally the tanks failed as the rocket hit the water vs anything that was an eng

> The detonation at the end was pretty spectacular too, but I suspect that structurally the tanks failed as the rocket hit the water vs anything that was an engineering failure. It's possible that SpaceX programed the AFTS to trigger some time after the rocket touched down in the water. Just to make sure that it completely submerges quickly. > I can easily imagine that flight 6 will be nominal end to end without any unintended damage. I think it depends on what you mean by "nominal". SpaceX ultimately wants to catch the 2nd stage as well. I suspect that they are a ways off of that, since it would have to approach over land. The FAA is going to need to have very high confidence that it will do exactly what it's designed to do before they're going to allow that.

317070 2y ago
> Just to make sure that it completely submerges quickly. Why would they want to do that? (genuinly curious). I reckon there would be a lot of useful data left if they could recover or even just inspect the remains. The remains are one big tank, so it would have floated.
- eco 2y ago
  No doubt it would be very useful to recover. SpaceX isn't the only one who could pluck it out of the Indian ocean though. You don't want to leave a prototype for the most advanced Spacecraft ever made just sitting around for competitors to grab (most notably China which is currently speed running SpaceX-like designs).
  - creer 2y ago
    It landed right next to their own camera-bearing buoy. You can bet their own recovery ship was right nearby. And with access to radio control too. Likely with a couple US military ships on hand too.
    - wiz21c 2y ago
      I certainly hope so. Ocean are polluted enough and although such a ship is just a, well, drop in the ocean, the ideq of accepting to pollute more is unbearable to me, especially for a world class company like SpaceX...
      - EnigmaFlare 2y ago
        [dead]
      - dzhiurgis 2y ago
        Other than some electronics it's actually pretty clean vehicle - methane will gas off, steel will quickly disintegrate in water, there isn't tons of plastic or paint.
      - inglor_cz 2y ago
        Looking at the composition of the ship, it won't be polluting the ocean much. No people on board to produce trash etc., mostly just plain stainless steel and a bit of ceramics that will make great hiding spot for the abyssal fish for a few years.
    - m4rtink 2y ago
      It might not be that simple - I've read an article how they recovered one of the solid rocket boosters from the first successful Ariane 5 flight to check all was fine. IIRC it was a slog, they had to tow it back very very slowly, avoid it sinking, fighting all kinds of weather and tow line issues, etc. Have not found the article, but there is a picture how it looked like[0]. With Starship it could have been similar & possibly worse given the size and more complex shape (various voids that might fill/drain & the thing is not really built for floating). Also you are in the middle of an ocean (Indian in this case) with potential for all kinds of weather on the way. Towing might again be very slow, so you might need to stage a massive submersible transport ship or something similar to make a recovery successful. And then the thing might still tip over and explode anyway - meaning all this was in vain. I think is most likely they won't bother and instead just stream as much data as possible over Starlink in real time (or heck, even via WiFi once the buoy is in range) for analysis. They want to catch the shop eventually anyway, so manual post flight analysis will wait. They can now check all over the first recovered booster anyway. :) [0] https://www.flickr.com/photos/europeanspaceagency/3700131835 https://www.flickr.com/photos/europeanspaceagency/3700131835
  - esskay 2y ago
    Yep this will be the reason. And lets not forget that Bezos was able to find and recover the Apollo 11 Saturn V engines from point nemo. If that was relatively simple you can bet plucking a freshly dropped entire starship from the indian ocean would be a doddle, especially when sat views likely show exactly where it landed.
    - walrus01 2y ago
      I'm fairly certain the Apollo first stage engines were recovered from a location relatively close to Florida/Bahamas, just east of the launch site. Not point nemo.
      - craigmoliver 2y ago
        That is correct, off FL. The recovered engines were from the first stage they would never have made it half way around the world. Point Nemo is used to stash spacecraft that were in orbit.
  - m4rtink 2y ago
    Also a yacht of a fishing boat could run into it in the night and sink - eq it could become an unmarked floating hazard.
iknowstuff 2y ago
correct me if I’m wrong but I don’t think the second stage is meant to be caught. It will have legs to land on Earth/Mars without any landing infrastructure.
- sebzim4500 2y ago
  It will have legs for Mars but they plan on catching it on Earth.
- ls612 2y ago
  It is expected to land astronauts on the Moon as well this decade, which will certainly require legs.
  - DarmokJalad1701 2y ago
    That is a different version. The ones launching/landing on Earth are supposed to be caught by arms similar to the booster.
    - gibolt 2y ago
      The ones for other celestial bodies are also planned to return to Earth... Being inside one as it does the belly flop will be quite the experience.
      - ncallaway 2y ago
        Pretty sure the Artemis lunar missions are going to use a different vehicle for Earth to LEO and LEO to Earth, so I don’t think anyone will be inside a Starship belly flop for quite some time
  - irrational 2y ago
    Or have the tower on the moon catch it.
- reagansdi 2y ago
  [flagged]
kedv 2y ago
Why is SpaceX choosing to land the booster on the Mechazilla arms instead of performing a soft ground landing like the Falcon 9 booster?
- syncsynchalt 2y ago
  1) legs are heavy 2) empty rockets are stronger in tension than compression the scale of Superheavy is such that the above two items are making the arms scheme make sense. The number of engines also gives this rocket the ability to hover, which probably makes the scheme easier to pull off.
  - anymouse123456 2y ago
    It's my understanding that these engines can be driven with variable power, which also makes deceleration and controlled hover more feasible.
    - syncsynchalt 2y ago
      This was also true for this engine's predecessor, the Merlin 1D. However that engine's rocket (the Falcon 9) can't hover, as the power of a single engine throttled to its lowest setting still overcomes the weight of a nearly-empty booster. All high performance engines tend to only throttle in a range in the upper half of the engine's performance, the difference making hovering possible in this case is that the Super Heavy has _so many_ engines that it can turn off. This is a sort of secondary throttling, or meta-throttling, and the rocket can use the combination of engine throttling and engine-off to hover comfortably (while near-empty) with three engines going.
      - anymouse123456 2y ago
        Thanks for the clarification!
  - askvictor 2y ago
    > 2) empty rockets are stronger in tension than compression True, but wouldn't the deceleration burn be putting much more compression onto the near-empty rocket than the landing?
stetrain 2y ago
> It's possible that SpaceX programed the AFTS to trigger some time after the rocket touched down in the water. Just to make sure that it completely submerges quickly. The SpaceX host on the stream said that they were going to try and touch it down on the water at more of an angle than the previous flight to attempt to get it to survive the initial splash-down so they could get some more data and video footage. Obviously this wasn't guaranteed to succeed, but it indicates that they weren't planning to immediately detonate the ship on touchdown. As I recall it was common on the early Falcon 9 landing tests that splashed down in the ocean to also explode after tipping over and smacking the water. Once they're actually landing them on a pad, tower, or ship that should be much less of an issue.
- chippiewill 2y ago
  Yeah, I don't think SpaceX planned for a RUD on tip-over (even if they did anticipate it). I think they've towed stuff in the sea before so I would have thought that'd be their preference if it were possible.
  - stetrain 2y ago
    Yeah. It wasn't planned, but was a likely outcome. I'm not sure if they would have actually attempted to tow this one somewhere given its location in the Indian Ocean, but they might have taken the opportunity to do some inspections before sinking it.
  - LorenPechtel 2y ago
    They don't want the booster actually landing in the water. They managed to do one test so well it survived--and then it became a hazard to navigation.

317070 2y ago

> Just to make sure that it completely submerges quickly. Why would they want to do that? (genuinly curious). I reckon there would be a lot of useful data left if they could recover or even just inspect the remains. The remains are one big tank, so it would have floated.

eco 2y ago
No doubt it would be very useful to recover. SpaceX isn't the only one who could pluck it out of the Indian ocean though. You don't want to leave a prototype for the most advanced Spacecraft ever made just sitting around for competitors to grab (most notably China which is currently speed running SpaceX-like designs).
- creer 2y ago
  It landed right next to their own camera-bearing buoy. You can bet their own recovery ship was right nearby. And with access to radio control too. Likely with a couple US military ships on hand too.
  - wiz21c 2y ago
    I certainly hope so. Ocean are polluted enough and although such a ship is just a, well, drop in the ocean, the ideq of accepting to pollute more is unbearable to me, especially for a world class company like SpaceX...
    - EnigmaFlare 2y ago
      [dead]
    - dzhiurgis 2y ago
      Other than some electronics it's actually pretty clean vehicle - methane will gas off, steel will quickly disintegrate in water, there isn't tons of plastic or paint.
    - inglor_cz 2y ago
      Looking at the composition of the ship, it won't be polluting the ocean much. No people on board to produce trash etc., mostly just plain stainless steel and a bit of ceramics that will make great hiding spot for the abyssal fish for a few years.
  - m4rtink 2y ago
    It might not be that simple - I've read an article how they recovered one of the solid rocket boosters from the first successful Ariane 5 flight to check all was fine. IIRC it was a slog, they had to tow it back very very slowly, avoid it sinking, fighting all kinds of weather and tow line issues, etc. Have not found the article, but there is a picture how it looked like[0]. With Starship it could have been similar & possibly worse given the size and more complex shape (various voids that might fill/drain & the thing is not really built for floating). Also you are in the middle of an ocean (Indian in this case) with potential for all kinds of weather on the way. Towing might again be very slow, so you might need to stage a massive submersible transport ship or something similar to make a recovery successful. And then the thing might still tip over and explode anyway - meaning all this was in vain. I think is most likely they won't bother and instead just stream as much data as possible over Starlink in real time (or heck, even via WiFi once the buoy is in range) for analysis. They want to catch the shop eventually anyway, so manual post flight analysis will wait. They can now check all over the first recovered booster anyway. :) [0] https://www.flickr.com/photos/europeanspaceagency/3700131835 https://www.flickr.com/photos/europeanspaceagency/3700131835
- esskay 2y ago
  Yep this will be the reason. And lets not forget that Bezos was able to find and recover the Apollo 11 Saturn V engines from point nemo. If that was relatively simple you can bet plucking a freshly dropped entire starship from the indian ocean would be a doddle, especially when sat views likely show exactly where it landed.
  - walrus01 2y ago
    I'm fairly certain the Apollo first stage engines were recovered from a location relatively close to Florida/Bahamas, just east of the launch site. Not point nemo.
    - craigmoliver 2y ago
      That is correct, off FL. The recovered engines were from the first stage they would never have made it half way around the world. Point Nemo is used to stash spacecraft that were in orbit.
- m4rtink 2y ago
  Also a yacht of a fishing boat could run into it in the night and sink - eq it could become an unmarked floating hazard.

iknowstuff 2y ago

correct me if I’m wrong but I don’t think the second stage is meant to be caught. It will have legs to land on Earth/Mars without any landing infrastructure.

sebzim4500 2y ago
It will have legs for Mars but they plan on catching it on Earth.
ls612 2y ago
It is expected to land astronauts on the Moon as well this decade, which will certainly require legs.
- DarmokJalad1701 2y ago
  That is a different version. The ones launching/landing on Earth are supposed to be caught by arms similar to the booster.
  - gibolt 2y ago
    The ones for other celestial bodies are also planned to return to Earth... Being inside one as it does the belly flop will be quite the experience.
    - ncallaway 2y ago
      Pretty sure the Artemis lunar missions are going to use a different vehicle for Earth to LEO and LEO to Earth, so I don’t think anyone will be inside a Starship belly flop for quite some time
- irrational 2y ago
  Or have the tower on the moon catch it.
reagansdi 2y ago
[flagged]

kedv 2y ago

Why is SpaceX choosing to land the booster on the Mechazilla arms instead of performing a soft ground landing like the Falcon 9 booster?

syncsynchalt 2y ago
1) legs are heavy 2) empty rockets are stronger in tension than compression the scale of Superheavy is such that the above two items are making the arms scheme make sense. The number of engines also gives this rocket the ability to hover, which probably makes the scheme easier to pull off.
- anymouse123456 2y ago
  It's my understanding that these engines can be driven with variable power, which also makes deceleration and controlled hover more feasible.
  - syncsynchalt 2y ago
    This was also true for this engine's predecessor, the Merlin 1D. However that engine's rocket (the Falcon 9) can't hover, as the power of a single engine throttled to its lowest setting still overcomes the weight of a nearly-empty booster. All high performance engines tend to only throttle in a range in the upper half of the engine's performance, the difference making hovering possible in this case is that the Super Heavy has _so many_ engines that it can turn off. This is a sort of secondary throttling, or meta-throttling, and the rocket can use the combination of engine throttling and engine-off to hover comfortably (while near-empty) with three engines going.
    - anymouse123456 2y ago
      Thanks for the clarification!
- askvictor 2y ago
  > 2) empty rockets are stronger in tension than compression True, but wouldn't the deceleration burn be putting much more compression onto the near-empty rocket than the landing?

stetrain 2y ago

> It's possible that SpaceX programed the AFTS to trigger some time after the rocket touched down in the water. Just to make sure that it completely submerges quickly. The SpaceX host on the stream said that they were going to try and touch it down on the water at more of an angle than the previous flight to attempt to get it to survive the initial splash-down so they could get some more data and video footage. Obviously this wasn't guaranteed to succeed, but it indicates that they weren't planning to immediately detonate the ship on touchdown. As I recall it was common on the early Falcon 9 landing tests that splashed down in the ocean to also explode after tipping over and smacking the water. Once they're actually landing them on a pad, tower, or ship that should be much less of an issue.

chippiewill 2y ago
Yeah, I don't think SpaceX planned for a RUD on tip-over (even if they did anticipate it). I think they've towed stuff in the sea before so I would have thought that'd be their preference if it were possible.
- stetrain 2y ago
  Yeah. It wasn't planned, but was a likely outcome. I'm not sure if they would have actually attempted to tow this one somewhere given its location in the Indian Ocean, but they might have taken the opportunity to do some inspections before sinking it.
- LorenPechtel 2y ago
  They don't want the booster actually landing in the water. They managed to do one test so well it survived--and then it became a hazard to navigation.