8 ms·

I can’t tell if this is satirical, but rockets have not proven their reliability much better than 94% for an unmanned rocket and 99% for manned. Airplanes have

I can’t tell if this is satirical, but rockets have not proven their reliability much better than 94% for an unmanned rocket and 99% for manned. Airplanes have reliabilities on a per journey basis around 99.9999%. Even if SpaceX is full of 10x engineers who can produce rockets 10x safer than before, that gets them to 99.9% reliability. The airline industry, for all of its faults, is multiple orders of magnitude safer than rockets. Perhaps rocket based vehicles are the future, but rocket failures must first become drastically more rare or at least less prone to everyone dying onboard in the case of a failure to be used in lieu of traditional airplanes. Rockets - https://space.stackexchange.com/questions/8566/what-is-the-success-failure-ratio-of-space-bound-rockets https://space.stackexchange.com/questions/8566/what-is-the-s... 2020 Airline safety - https://www.reuters.com/article/uk-airlines-safety/aviation-deaths-rise-worldwide-in-2020-even-as-fatal-incidents-flights-fall-idUKKBN2962OA https://www.reuters.com/article/uk-airlines-safety/aviation-...

paulsutter 6y ago
SpaceX scheduled to make a new Starship every 2.5 days by 2025 You might want to look at the early days of airplane safety, not the 2020 numbers. Look up reliablity learning curve, safety comes from doing a huge volume of flights. All existing rockets have a small number of flights EDIT: am a SpaceX shareholder and I’ve met with Elon more than once, so not sure what you mean by parasocial
- deleted 6y ago
  [deleted]
- staticman2 6y ago
  Whenever something related to Elon Musk comes up it becomes hard to sort out what is a reasonable claim versus an unreasonable one fueled by a parasocial relationship with Elon Musk.
- chrononaut 6y ago
  As an aside, I do get amused when Person A makes an argument that may not have explicit references, Person B rebuttals with explicit references, and Person A responds by instructing Person B to go look up their own references for Person A's own argument. Reminds me of the "All Birds are Cats" sketch by Clarke and Dave: https://www.youtube.com/watch?v=eIl1VuGTk3g https://www.youtube.com/watch?v=eIl1VuGTk3g (Relevant bit starts at 51s)
m4rtink 6y ago
It will be definitely interesting too watch Starship development progress - even just because it's actually in a big part a lot simpler vehicle than an airliner. You see, there are those very top notch and quite a bit complex raptor engines powering it, but modern efficient jet engines are also pretty complex. The rest is basically "just" two cans of propelant and some very basic cold gas thrusters and big but simple aerosurfaces. Also while indeed the energies Starship needs to handle at any given time are much bigger, it needs to handle them for minutes at a time (launch, landing) versus an airliner fighting air resistance and 10 different types of weather during a 12 hour transcontinental flight. Not to mention passenger and crew amenities you dont need to lug with you with a ~30 minute hop time. Rocket engines also have their own oxidizer on board so FOD ingestion or birdstrike is not an issue. And for launch and landing you need an isolated but rather simple and small area compared to the many kilometers of runways, taxiways and other airport infrastructure. Lastly they run on liquid oxygen & methane, which might be actually cheaper and easier to get than jet grade kerosene, at least over time. So indeed, Starship definitely is rocket science but it also does not have many pain points of modern airliners.
- sudosysgen 6y ago
  Airliners can glide. Rockets can't. That's your big difference right there. Wings are also way simpler than rockets. You also have way more time to try to fix or workaround issues. Reliability wise, airplanes will always be much better than rockets, especially if you include a propulsive landing.
  - m4rtink 6y ago
    Sure, gliding helped to avoid many catastrophes (Gimli Glider, Hudson miracle, etc.) but the thing is - does it make sense for a rocketship ? On a point to point flight you are going to land (or impact) somewhere and you need a couple working engines to land safely, the same as you need working control systems to glide to an airport. Still, Starship does not really need an airport for emergency landing - anything reasonably level will very quickly become a landing pad once the raptors get going for landing. Also as for wings - those seem very complex to me on a modern airliner - flaps, spoilers, ailerons, wingless, integral fuel tanks, etc. In comparison to that starship is a lightweight water tower with a couple metal barn doors attached - much simpler structure with far less moving parts.
btilly 6y ago
No, rockets have not proven their reliability. Reliability is something that gets developed through volume of operations combined with a safety and feedback procedure that slowly catches ever rarer problems. And then gets proven through an even larger volume of successes. Airplanes have gone through that learning curve, rockets have not. There have been around 6000 orbital launches, in total. That's across all countries, all companies, and all time. This is simply insufficient volume to learn how to do it safely. When airplanes were at a similar level of maturity they crashed regularly for every reason from mechanical failure to the fact that people didn't know how to fly into a cloud and not fall out of the sky. (It turns out that in about 15 minutes the inner ear gets confused and you're almost certainly trapped in a spiral if you don't have the right instruments.) Judging from their public comments, SpaceX is hoping to get 3 launches per day from each Starship, and is hoping to produce hundreds of starships per year. Which means that after a few years, they intend to get to more orbital launches per day than we have had orbital launches in all of human history. If they do so, there is every reason to believe that they will learn how to make rockets safer. Not by a factor of 5 or 10 because they have good engineers. But to the level of, say, car travel. Because they will develop the volume of operations that will let them find the things that go wrong one flight out of 10,000. (It will take rockets a long time to get to the volume of operations that enables them to match airplanes. But in the long run there is no reason that rockets can't become that good.)
- Gene_Parmesan 6y ago
  > Judging from their public comments, SpaceX is hoping to get 3 launches per day from each Starship, and is hoping to produce hundreds of starships per year. Which means that after a few years, they intend to get to more orbital launches per day than we have had orbital launches in all of human history. This sort of talk has always seemed to be really infeasible to the point of being nonsensical. What could possibly drive the need for 6000 orbital launches per day? Where are the fuel resources going to come from? This sort of pie-in-the-sky thinking I don't find motivating at all, I just find it to be so excessive that I have no choice but to immediately dismiss it. The double-standard with eco-consciousness gets me too. Green cars, green home power, green everything... but 6000 orbital launches per day. What? I'm not trying to be a SpaceX hater - although I admit to being very sick of the Musk fanboyism - I just genuinely don't understand where these claims are coming from.

paulsutter 6y ago

SpaceX scheduled to make a new Starship every 2.5 days by 2025 You might want to look at the early days of airplane safety, not the 2020 numbers. Look up reliablity learning curve, safety comes from doing a huge volume of flights. All existing rockets have a small number of flights EDIT: am a SpaceX shareholder and I’ve met with Elon more than once, so not sure what you mean by parasocial

deleted 6y ago
[deleted]
staticman2 6y ago
Whenever something related to Elon Musk comes up it becomes hard to sort out what is a reasonable claim versus an unreasonable one fueled by a parasocial relationship with Elon Musk.
chrononaut 6y ago
As an aside, I do get amused when Person A makes an argument that may not have explicit references, Person B rebuttals with explicit references, and Person A responds by instructing Person B to go look up their own references for Person A's own argument. Reminds me of the "All Birds are Cats" sketch by Clarke and Dave: https://www.youtube.com/watch?v=eIl1VuGTk3g https://www.youtube.com/watch?v=eIl1VuGTk3g (Relevant bit starts at 51s)

m4rtink 6y ago

It will be definitely interesting too watch Starship development progress - even just because it's actually in a big part a lot simpler vehicle than an airliner. You see, there are those very top notch and quite a bit complex raptor engines powering it, but modern efficient jet engines are also pretty complex. The rest is basically "just" two cans of propelant and some very basic cold gas thrusters and big but simple aerosurfaces. Also while indeed the energies Starship needs to handle at any given time are much bigger, it needs to handle them for minutes at a time (launch, landing) versus an airliner fighting air resistance and 10 different types of weather during a 12 hour transcontinental flight. Not to mention passenger and crew amenities you dont need to lug with you with a ~30 minute hop time. Rocket engines also have their own oxidizer on board so FOD ingestion or birdstrike is not an issue. And for launch and landing you need an isolated but rather simple and small area compared to the many kilometers of runways, taxiways and other airport infrastructure. Lastly they run on liquid oxygen & methane, which might be actually cheaper and easier to get than jet grade kerosene, at least over time. So indeed, Starship definitely is rocket science but it also does not have many pain points of modern airliners.

sudosysgen 6y ago
Airliners can glide. Rockets can't. That's your big difference right there. Wings are also way simpler than rockets. You also have way more time to try to fix or workaround issues. Reliability wise, airplanes will always be much better than rockets, especially if you include a propulsive landing.
- m4rtink 6y ago
  Sure, gliding helped to avoid many catastrophes (Gimli Glider, Hudson miracle, etc.) but the thing is - does it make sense for a rocketship ? On a point to point flight you are going to land (or impact) somewhere and you need a couple working engines to land safely, the same as you need working control systems to glide to an airport. Still, Starship does not really need an airport for emergency landing - anything reasonably level will very quickly become a landing pad once the raptors get going for landing. Also as for wings - those seem very complex to me on a modern airliner - flaps, spoilers, ailerons, wingless, integral fuel tanks, etc. In comparison to that starship is a lightweight water tower with a couple metal barn doors attached - much simpler structure with far less moving parts.

btilly 6y ago

No, rockets have not proven their reliability. Reliability is something that gets developed through volume of operations combined with a safety and feedback procedure that slowly catches ever rarer problems. And then gets proven through an even larger volume of successes. Airplanes have gone through that learning curve, rockets have not. There have been around 6000 orbital launches, in total. That's across all countries, all companies, and all time. This is simply insufficient volume to learn how to do it safely. When airplanes were at a similar level of maturity they crashed regularly for every reason from mechanical failure to the fact that people didn't know how to fly into a cloud and not fall out of the sky. (It turns out that in about 15 minutes the inner ear gets confused and you're almost certainly trapped in a spiral if you don't have the right instruments.) Judging from their public comments, SpaceX is hoping to get 3 launches per day from each Starship, and is hoping to produce hundreds of starships per year. Which means that after a few years, they intend to get to more orbital launches per day than we have had orbital launches in all of human history. If they do so, there is every reason to believe that they will learn how to make rockets safer. Not by a factor of 5 or 10 because they have good engineers. But to the level of, say, car travel. Because they will develop the volume of operations that will let them find the things that go wrong one flight out of 10,000. (It will take rockets a long time to get to the volume of operations that enables them to match airplanes. But in the long run there is no reason that rockets can't become that good.)

Gene_Parmesan 6y ago
> Judging from their public comments, SpaceX is hoping to get 3 launches per day from each Starship, and is hoping to produce hundreds of starships per year. Which means that after a few years, they intend to get to more orbital launches per day than we have had orbital launches in all of human history. This sort of talk has always seemed to be really infeasible to the point of being nonsensical. What could possibly drive the need for 6000 orbital launches per day? Where are the fuel resources going to come from? This sort of pie-in-the-sky thinking I don't find motivating at all, I just find it to be so excessive that I have no choice but to immediately dismiss it. The double-standard with eco-consciousness gets me too. Green cars, green home power, green everything... but 6000 orbital launches per day. What? I'm not trying to be a SpaceX hater - although I admit to being very sick of the Musk fanboyism - I just genuinely don't understand where these claims are coming from.