7 ms·

SpaceX's unmatched streak of perfection with the Falcon 9 rocket is over

88 points by makaimc 2y ago

LorenDB 2y ago
300+ successful launches in an 8-year span is incredible.
jmdeschamps 2y ago
Still unmatched, even if imperfect...
m2fkxy 2y ago
bad week for upper stage engines!
- perlgeek 2y ago
  Upper stage engines are notoriously difficult, because the operate in a very different environment than we're used to, under annoying mass constraints, and after exposure to the rigors of a rocket launch (high vibrations and acceleration). Also, they must ignite without any help from the ground, without any felt gravity (which really helps with pumping fuel and oxidizer). All that makes the previous run of successful missions all the more impressive.
  - anovikov 2y ago
    Worst part of it is that lower stage engines, in SpaceX's case, have been thoroughly studied after flight, because they return back in working condition, so any quirks in them have been found and fixed long ago. Upper stage engine is based on the lower stage one but all of the delta between them could only be validated through telemetry - there's never a returned article in a recognisable shape to study and fix bugs in - because upper stage is not reusable and mostly burns up upon reentry. It makes hidden, rare bugs very likely.
    - HPsquared 2y ago
      There's a lot of commonality. Especially as the first stage also needs to relight in a similar environment for the boostback burn. Engine commonality is a real strength of the Falcon 9 architecture, it keeps that delta as small as possible.
  - bell-cot 2y ago
    Both https://en.wikipedia.org/wiki/Ullage_motor https://en.wikipedia.org/wiki/Ullage_motor and https://en.wikipedia.org/wiki/Multistage_rocket#Hot-staging https://en.wikipedia.org/wiki/Multistage_rocket#Hot-staging can eliminate the "Ignite in free fall" requirement. At the cost of introducing other complexities in the rocket's design.
  - krisoft 2y ago
    I agree with the reasons you list. Would like to add one more which is somewhat specific to spacex. They are reusing the first stage, but can't reuse the second stage. Which provides complications in two ways: Every second stage they fire is a brand new one. There are no "flight-proven" second stages. (of course the design is flight proven, but the actual piece of hardware itself is not.) The other one is since the second stages are not recovered it is much harder to do an after-flight engineering analysis on them. With the first stage SpaceX have most of them back after the flight. That means they can check that all is looking as they expect it. If something with the design is "marginal" in a way they haven't designed them to be marginal they can adjust the design to improve it. With a second stage you can not do that. Of course this is the default state of every other rocket ever flown. But in spacex's case I would expect the first stage just a tiny bit more reliable than the second stage because of this. (Just a tiny bit, since there is a lot of commonality between the stages)
    - grecy 2y ago
      > The other one is since the second stages are not recovered it is much harder to do an after-flight engineering analysis on them This raises and interesting question - do you think SpaceX will attempt to recover a Falcon 9 second stage with Starship at some point? It would be a great technology demonstrator for Starship, and finally gets them a F9 second stage to inspect. Win win.
      - krisoft 2y ago
        Oh. Interesting! I haven't thought of that. It sounds super cool, although my gut reaction is that it would be a lot of work for not much bang. My childish imagination pictures the proposal as the Agena target vehicle from the Gemini IX test flight. There the fairing did not separate correctly leaving the docking target looking like a hungry space alligator: https://www.nasa.gov/wp-content/uploads/2016/05/5-s66-37966-b.jpg https://www.nasa.gov/wp-content/uploads/2016/05/5-s66-37966-... One could imagine the aligator gobling up a drifting second stage. :D It would absolutely not look like that in reality, but if life were a cartoon that is how it would happen. :)
  - bell-cot 2y ago
    If anyone is unaware - the ESA's new Ariane 6 just suffered an "upper stage relight fail" during its first test flight: https://arstechnica.com/space/2024/07/europes-first-ariane-6-flight-achieved-most-of-its-goals-but-ended-prematurely/ https://arstechnica.com/space/2024/07/europes-first-ariane-6... https://www.youtube.com/watch?v=pgTbThZg6Zg https://www.youtube.com/watch?v=pgTbThZg6Zg
bell-cot 2y ago
> A few minutes after liftoff of SpaceX's Starlink 9-3 mission, veteran observers of SpaceX launches noticed an unusual build-up of ice around the top of the Merlin Vacuum engine, which consumes a propellant mixture of super-chilled kerosene and cryogenic liquid oxygen. [...] > Numerous chunks of ice fell away from the rocket as the upper stage engine powered into orbit, but the Merlin Vacuum, or M-Vac, engine appeared to complete its first burn as planned. A leak in the oxidizer system or a problem with insulation could lead to ice accumulation, although the exact cause, and its possible link to the engine malfunction later in flight, will be the focus of SpaceX's investigation into the failure. > A second burn with the upper stage engine was supposed to raise the perigee, or low point, of the rocket's orbit well above the atmosphere before releasing 20 Starlink satellites [...]. > "Upper stage restart to raise perigee resulted in an engine RUD for reasons currently unknown," Musk wrote... For Falcon 9 manned launches, there are a whole series of abort modes and we-didn't-get-to-orbit splashdown locations: https://www.nasaspaceflight.com/2020/05/examining-crew-dragons-launch-abort-modes-and-splashdown-locations/ https://www.nasaspaceflight.com/2020/05/examining-crew-drago... It'd be interesting to know where in this mission's flight profile, if it had been manned, the launch director would have ordered an abort. That LOX leaks often lead to explosions is Rocket Science 101.
- mhandley 2y ago
  If this were a manned launch, I would guess that unless the telemetry showed something very off, they would most likely have completed the full second stage burn. That would have left Dragon in a 190 x 205 km orbit, which is stable. If I understand correctly, SpaceX doesn't do orbit raising for Dragon by restarting the second stage engine (which is where the RUD happened on this Starlink launch), but rather uses Dragon's own thrusters to raise orbit. So most likely this would have been a successful flight. On Starlink flights they don't have the margin to reach a full circular orbit on a single burn. It's more efficient to achieve an eliptical orbit initially, then coast and perform a second burn at apogee. It's that second burn that proved problematic this time. Edit: having watched the videos, it would have been clear to SpaceX that they had an oxygen leak right from the start of the second stage burn. So I guess it depends on whether the pressures and flow rates within the engine looked OK. If the leak was external to the engine, then the main risk would be running of out LoX - engines really really don't like ingesting a gas bubble instead of liquid. If it looked like they were getting low on LoX, I'm sure they would have initiated one of the abort modes. Otherwise it's probably safer to continue to orbit. They do have cameras inside the tanks, in addition to all the telemetry - they have occasionally shown then on the livestream.
trompetenaccoun 2y ago
Tangentially related: Most journalists - especially in tech these days - seem to be doing practically no original or investigative work and simply rehash what they read on Twitter & co. Are there any decent apps that do the same thing? For example I'd like to say "Follow everything SpaceX-related from these primary sources and give me regular updates/summaries". I don't care to read people's opinions on it, just the aggregated raw info would be nice.
- Workaccount2 2y ago
  I think the irony is completely lost on them too when they complain that LLM's are grossly abusing their copyright.
- HPsquared 2y ago
  This is what Google News etc should be like.
- JumpCrisscross 2y ago
  > Are there any decent apps that do the same thing? SpaceFlightNow is half decent for aerospace.
- kranke155 2y ago
  Eric Berger on Ars can do that. This is not his article however.
- rozab 2y ago
  Ars Technica space stuff is actually top quality, with Eric Berger they have the best team
- bell-cot 2y ago
  For expert-ish and well-informed failure analysis, I've noticed that Scott Manley ( https://www.youtube.com/c/szyzyg/videos https://www.youtube.com/c/szyzyg/videos ) usually does a very good job.
  - ClumsyPilot 2y ago
seydor 2y ago
well i know ars is not using chatGPT because of the grammatical errors
- deleted 2y ago
  [deleted]
sidcool 2y ago
Such a bad title to a story. "over" means they will never be able to create that streak again.
- Uvix 2y ago
  Even if they’re able to, does SpaceX want to keep operating Falcon 9 through 2032 or beyond? I would have thought they’d migrate to Starship by then.
  - sebzim4500 2y ago
    If the target is 300 launches in a row they can do that in under 3 years, so I think it's fully possible they beat it.
- brookst 2y ago
  Disagree. It means that their streak, which had been running for quite a while, has ended. “streak” here is a noun referring to the specific successful launches. Much like saying a sports team’s 10-game winning streak is over does not mean they will never win 10 games in a row again.
- jjk166 2y ago
  That would be a new streak, not the one that just ended. Also this version of the rocket can never get back to 100%.
zitterbewegung 2y ago
It doesn’t take rocket science to understand that rockets eventually have a success rate of less than 100% . (Edited changed failure rate to success from child comment)
- mihaic 2y ago
  I think you mean success rate, but very true observation regardless.
- ieee2 2y ago
  Yes, there is not a single thing in the world working with 100% success (0 failure rate). World does not work like this. Everything ages.
  - krisoft 2y ago
    > Everything ages. That is true, but it is not directly related to this issue. SpaceX doesn't (can't) reuse second stages. (For now.) The one in question which had the anomaly was a "brand new" second stage. It is more likely that either this is due to a defect which escaped their QA, or a design issue with a very low probability rolling a nat-1 this time, or some change they introduced not working out as they expected. I would not describe any of those as "aging".
  - throwawaymaths 2y ago
    You can get cancelled before you fail (and after you launch), resulting in 100% success.
- throwawaymaths 2y ago
  No, that's not true. Atlas V and ~Delta IV heavy had a 100% success rate. Ok strictly speaking atlas V is not 100% yet. There are 16 more opportunities for failure.
  - imglorp 2y ago
    Those two systems have 116 launches combined. If there was one failure tomorrow, that would be a 99.1% success rate vs falcon now at 99.7%.
JumpCrisscross 2y ago
Modern rocketry is somewhere between WWI and WWII aviation. We’re beginning to mass manufacture, but the leading edge advances so quickly that learning curves have limited runtime. Alongside new designs, new materials are being invented and deployed across America and China (and to a limited degree Europe.) Most importantly, we can tune risk and and reward across the production line; the crewed Falcon 9/Dragon launches are far more conservative than their Starlink + rideshare ones.
- mft_ 2y ago
  > Most importantly, we can tune risk and and reward across the production line; the crewed Falcon 9/Dragon launches are far more conservative than their Starlink + rideshare ones. Do you have any details about how this is achieved? What changes?
  - JumpCrisscross 2y ago
    > Do you have any details about how this is achieved? What changes? Wider margins of safety. More frequent fallback plana/turnouts. But for the most part: less. Fewer changes. You go back to a proven model that’s flown more. It won’t have the latest kit. But that’s the point.
    - canadianfella 2y ago
      [dead]
    - avmich 2y ago
      > but the leading edge advances so quickly that learning curves have limited runtime. > It won’t have the latest kit. So does the SOTA advances too quickly or not?
      - JumpCrisscross 2y ago
        > So does the SOTA advances too quickly or not? By SOTA, do you mean anti-collision kit?
patrickwalton 2y ago
Amazing to me that it's not the reused element that failed. It's as though re-flying hardware that's already proven to work is more reliable!
deleted 2y ago
[deleted]
jtwaleson 2y ago
I'd argue that going for 0 failures in virtually any domain will lead to inefficiency. You need some failures to get the feedback that you've "under-engineered" something. Without failures, you can guarantee that you've over-engineered it. In a similar vein, I think proper risk acceptance policies shouldn't say "security/safety is our #1 priority", just like a good SLA doesn't guarantee 100% uptime. When you set a 99.9% uptime SLA, make sure you're actually down sometimes. When you want efficient rockets, you have to see some of them crash.

88 points by makaimc 2y ago

LorenDB 2y ago

300+ successful launches in an 8-year span is incredible.

jmdeschamps 2y ago

Still unmatched, even if imperfect...

m2fkxy 2y ago

bad week for upper stage engines!

perlgeek 2y ago
Upper stage engines are notoriously difficult, because the operate in a very different environment than we're used to, under annoying mass constraints, and after exposure to the rigors of a rocket launch (high vibrations and acceleration). Also, they must ignite without any help from the ground, without any felt gravity (which really helps with pumping fuel and oxidizer). All that makes the previous run of successful missions all the more impressive.
- anovikov 2y ago
  Worst part of it is that lower stage engines, in SpaceX's case, have been thoroughly studied after flight, because they return back in working condition, so any quirks in them have been found and fixed long ago. Upper stage engine is based on the lower stage one but all of the delta between them could only be validated through telemetry - there's never a returned article in a recognisable shape to study and fix bugs in - because upper stage is not reusable and mostly burns up upon reentry. It makes hidden, rare bugs very likely.
  - HPsquared 2y ago
    There's a lot of commonality. Especially as the first stage also needs to relight in a similar environment for the boostback burn. Engine commonality is a real strength of the Falcon 9 architecture, it keeps that delta as small as possible.
- bell-cot 2y ago
  Both https://en.wikipedia.org/wiki/Ullage_motor https://en.wikipedia.org/wiki/Ullage_motor and https://en.wikipedia.org/wiki/Multistage_rocket#Hot-staging https://en.wikipedia.org/wiki/Multistage_rocket#Hot-staging can eliminate the "Ignite in free fall" requirement. At the cost of introducing other complexities in the rocket's design.
- krisoft 2y ago
  I agree with the reasons you list. Would like to add one more which is somewhat specific to spacex. They are reusing the first stage, but can't reuse the second stage. Which provides complications in two ways: Every second stage they fire is a brand new one. There are no "flight-proven" second stages. (of course the design is flight proven, but the actual piece of hardware itself is not.) The other one is since the second stages are not recovered it is much harder to do an after-flight engineering analysis on them. With the first stage SpaceX have most of them back after the flight. That means they can check that all is looking as they expect it. If something with the design is "marginal" in a way they haven't designed them to be marginal they can adjust the design to improve it. With a second stage you can not do that. Of course this is the default state of every other rocket ever flown. But in spacex's case I would expect the first stage just a tiny bit more reliable than the second stage because of this. (Just a tiny bit, since there is a lot of commonality between the stages)
  - grecy 2y ago
    > The other one is since the second stages are not recovered it is much harder to do an after-flight engineering analysis on them This raises and interesting question - do you think SpaceX will attempt to recover a Falcon 9 second stage with Starship at some point? It would be a great technology demonstrator for Starship, and finally gets them a F9 second stage to inspect. Win win.
    - krisoft 2y ago
      Oh. Interesting! I haven't thought of that. It sounds super cool, although my gut reaction is that it would be a lot of work for not much bang. My childish imagination pictures the proposal as the Agena target vehicle from the Gemini IX test flight. There the fairing did not separate correctly leaving the docking target looking like a hungry space alligator: https://www.nasa.gov/wp-content/uploads/2016/05/5-s66-37966-b.jpg https://www.nasa.gov/wp-content/uploads/2016/05/5-s66-37966-... One could imagine the aligator gobling up a drifting second stage. :D It would absolutely not look like that in reality, but if life were a cartoon that is how it would happen. :)
- bell-cot 2y ago
  If anyone is unaware - the ESA's new Ariane 6 just suffered an "upper stage relight fail" during its first test flight: https://arstechnica.com/space/2024/07/europes-first-ariane-6-flight-achieved-most-of-its-goals-but-ended-prematurely/ https://arstechnica.com/space/2024/07/europes-first-ariane-6... https://www.youtube.com/watch?v=pgTbThZg6Zg https://www.youtube.com/watch?v=pgTbThZg6Zg

bell-cot 2y ago

> A few minutes after liftoff of SpaceX's Starlink 9-3 mission, veteran observers of SpaceX launches noticed an unusual build-up of ice around the top of the Merlin Vacuum engine, which consumes a propellant mixture of super-chilled kerosene and cryogenic liquid oxygen. [...] > Numerous chunks of ice fell away from the rocket as the upper stage engine powered into orbit, but the Merlin Vacuum, or M-Vac, engine appeared to complete its first burn as planned. A leak in the oxidizer system or a problem with insulation could lead to ice accumulation, although the exact cause, and its possible link to the engine malfunction later in flight, will be the focus of SpaceX's investigation into the failure. > A second burn with the upper stage engine was supposed to raise the perigee, or low point, of the rocket's orbit well above the atmosphere before releasing 20 Starlink satellites [...]. > "Upper stage restart to raise perigee resulted in an engine RUD for reasons currently unknown," Musk wrote... For Falcon 9 manned launches, there are a whole series of abort modes and we-didn't-get-to-orbit splashdown locations: https://www.nasaspaceflight.com/2020/05/examining-crew-dragons-launch-abort-modes-and-splashdown-locations/ https://www.nasaspaceflight.com/2020/05/examining-crew-drago... It'd be interesting to know where in this mission's flight profile, if it had been manned, the launch director would have ordered an abort. That LOX leaks often lead to explosions is Rocket Science 101.

mhandley 2y ago
If this were a manned launch, I would guess that unless the telemetry showed something very off, they would most likely have completed the full second stage burn. That would have left Dragon in a 190 x 205 km orbit, which is stable. If I understand correctly, SpaceX doesn't do orbit raising for Dragon by restarting the second stage engine (which is where the RUD happened on this Starlink launch), but rather uses Dragon's own thrusters to raise orbit. So most likely this would have been a successful flight. On Starlink flights they don't have the margin to reach a full circular orbit on a single burn. It's more efficient to achieve an eliptical orbit initially, then coast and perform a second burn at apogee. It's that second burn that proved problematic this time. Edit: having watched the videos, it would have been clear to SpaceX that they had an oxygen leak right from the start of the second stage burn. So I guess it depends on whether the pressures and flow rates within the engine looked OK. If the leak was external to the engine, then the main risk would be running of out LoX - engines really really don't like ingesting a gas bubble instead of liquid. If it looked like they were getting low on LoX, I'm sure they would have initiated one of the abort modes. Otherwise it's probably safer to continue to orbit. They do have cameras inside the tanks, in addition to all the telemetry - they have occasionally shown then on the livestream.

trompetenaccoun 2y ago

Tangentially related: Most journalists - especially in tech these days - seem to be doing practically no original or investigative work and simply rehash what they read on Twitter & co. Are there any decent apps that do the same thing? For example I'd like to say "Follow everything SpaceX-related from these primary sources and give me regular updates/summaries". I don't care to read people's opinions on it, just the aggregated raw info would be nice.

Workaccount2 2y ago
I think the irony is completely lost on them too when they complain that LLM's are grossly abusing their copyright.
HPsquared 2y ago
This is what Google News etc should be like.
JumpCrisscross 2y ago
> Are there any decent apps that do the same thing? SpaceFlightNow is half decent for aerospace.
kranke155 2y ago
Eric Berger on Ars can do that. This is not his article however.
rozab 2y ago
Ars Technica space stuff is actually top quality, with Eric Berger they have the best team
bell-cot 2y ago
For expert-ish and well-informed failure analysis, I've noticed that Scott Manley ( https://www.youtube.com/c/szyzyg/videos https://www.youtube.com/c/szyzyg/videos ) usually does a very good job.
- ClumsyPilot 2y ago

seydor 2y ago

well i know ars is not using chatGPT because of the grammatical errors

deleted 2y ago
[deleted]

sidcool 2y ago

Such a bad title to a story. "over" means they will never be able to create that streak again.

Uvix 2y ago
Even if they’re able to, does SpaceX want to keep operating Falcon 9 through 2032 or beyond? I would have thought they’d migrate to Starship by then.
- sebzim4500 2y ago
  If the target is 300 launches in a row they can do that in under 3 years, so I think it's fully possible they beat it.
brookst 2y ago
Disagree. It means that their streak, which had been running for quite a while, has ended. “streak” here is a noun referring to the specific successful launches. Much like saying a sports team’s 10-game winning streak is over does not mean they will never win 10 games in a row again.
jjk166 2y ago
That would be a new streak, not the one that just ended. Also this version of the rocket can never get back to 100%.

zitterbewegung 2y ago

It doesn’t take rocket science to understand that rockets eventually have a success rate of less than 100% . (Edited changed failure rate to success from child comment)

mihaic 2y ago
I think you mean success rate, but very true observation regardless.
ieee2 2y ago
Yes, there is not a single thing in the world working with 100% success (0 failure rate). World does not work like this. Everything ages.
- krisoft 2y ago
  > Everything ages. That is true, but it is not directly related to this issue. SpaceX doesn't (can't) reuse second stages. (For now.) The one in question which had the anomaly was a "brand new" second stage. It is more likely that either this is due to a defect which escaped their QA, or a design issue with a very low probability rolling a nat-1 this time, or some change they introduced not working out as they expected. I would not describe any of those as "aging".
- throwawaymaths 2y ago
  You can get cancelled before you fail (and after you launch), resulting in 100% success.
throwawaymaths 2y ago
No, that's not true. Atlas V and ~Delta IV heavy had a 100% success rate. Ok strictly speaking atlas V is not 100% yet. There are 16 more opportunities for failure.
- imglorp 2y ago
  Those two systems have 116 launches combined. If there was one failure tomorrow, that would be a 99.1% success rate vs falcon now at 99.7%.

JumpCrisscross 2y ago

Modern rocketry is somewhere between WWI and WWII aviation. We’re beginning to mass manufacture, but the leading edge advances so quickly that learning curves have limited runtime. Alongside new designs, new materials are being invented and deployed across America and China (and to a limited degree Europe.) Most importantly, we can tune risk and and reward across the production line; the crewed Falcon 9/Dragon launches are far more conservative than their Starlink + rideshare ones.

mft_ 2y ago
> Most importantly, we can tune risk and and reward across the production line; the crewed Falcon 9/Dragon launches are far more conservative than their Starlink + rideshare ones. Do you have any details about how this is achieved? What changes?
- JumpCrisscross 2y ago
  > Do you have any details about how this is achieved? What changes? Wider margins of safety. More frequent fallback plana/turnouts. But for the most part: less. Fewer changes. You go back to a proven model that’s flown more. It won’t have the latest kit. But that’s the point.
  - canadianfella 2y ago
    [dead]
  - avmich 2y ago
    > but the leading edge advances so quickly that learning curves have limited runtime. > It won’t have the latest kit. So does the SOTA advances too quickly or not?
    - JumpCrisscross 2y ago
      > So does the SOTA advances too quickly or not? By SOTA, do you mean anti-collision kit?

patrickwalton 2y ago

Amazing to me that it's not the reused element that failed. It's as though re-flying hardware that's already proven to work is more reliable!

deleted 2y ago

[deleted]

jtwaleson 2y ago

I'd argue that going for 0 failures in virtually any domain will lead to inefficiency. You need some failures to get the feedback that you've "under-engineered" something. Without failures, you can guarantee that you've over-engineered it. In a similar vein, I think proper risk acceptance policies shouldn't say "security/safety is our #1 priority", just like a good SLA doesn't guarantee 100% uptime. When you set a 99.9% uptime SLA, make sure you're actually down sometimes. When you want efficient rockets, you have to see some of them crash.