Abort options for Starship and Starship/SuperHeavy

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

[dglow]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

[dglow]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

Sorry, but you’re crossing the streams. The comparison is not between wildly different modes of transport, but among the various modes of failure within a mode of transport.

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

Sorry, but you’re crossing the streams. The comparison is not between wildly different modes of transport, but among the various modes of failure within a mode of transport.

You said, "It's why nobody is handed a parachute when they board an airline flight.".

I answered that.

[dglow]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

Sorry, but you’re crossing the streams. The comparison is not between wildly different modes of transport, but among the various modes of failure within a mode of transport.

You said, "It's why nobody is handed a parachute when they board an airline flight.".

I answered that.

I did say that. And you answered by making a false comparison of airline safety to rocket safety.

Either we aren’t communicating well, or someone isn’t debating in good faith. I hope it’s the former.

[JayWee]

People, *taps the sign*

Option 1: The propulsion system is made so reliable that loss of thrust during ascent is sufficiently unlikely that no other abort system is needed and propulsive landing is equally reliable.
...
Option 1 is a no-brainer that does not need to be discussed. This is almost certainly the way to go for cargo. It will also be the way to go for landing on other planets where there is no or very thin atmosphere and as such no parachute/aerodynamic abort mode possible. This has been discussed to death in the old closed thread.
There are some who are very adamant that this is the only option Starship might ever need. This opinion, while valid, is hereby declared off topic for this thread, as it derails the technical discussion about actual abort systems. Please don't delute the discussion about possible abort options into a discussion whether starship needs abort options or not. Off topic. There's 52 pages of that right here: https://forum.nasaspaceflight.com/index.php?topic=43438.0
This includes the notion that "commercial airplanes have no abort system/parachutes either" - yes, we know that by now.
...
Option 2
I think this is where the most productive discussion can be. What would be possible designs. Which abort scenarios would they cover and which do they not? What would be the payload penalty? What would be additional marginal cost to launch (if any)? Can we come up with designs?
...
So let's focus on Option 2 please, shall we? :-)

[dglow]

People, *taps the sign*

Option 1: The propulsion system is made so reliable that loss of thrust during ascent is sufficiently unlikely that no other abort system is needed and propulsive landing is equally reliable.
...
Option 1 is a no-brainer that does not need to be discussed. This is almost certainly the way to go for cargo. It will also be the way to go for landing on other planets where there is no or very thin atmosphere and as such no parachute/aerodynamic abort mode possible. This has been discussed to death in the old closed thread.
There are some who are very adamant that this is the only option Starship might ever need. This opinion, while valid, is hereby declared off topic for this thread, as it derails the technical discussion about actual abort systems. Please don't delute the discussion about possible abort options into a discussion whether starship needs abort options or not. Off topic. There's 52 pages of that right here: https://forum.nasaspaceflight.com/index.php?topic=43438.0
This includes the notion that "commercial airplanes have no abort system/parachutes either" - yes, we know that by now.
...
Option 2
I think this is where the most productive discussion can be. What would be possible designs. Which abort scenarios would they cover and which do they not? What would be the payload penalty? What would be additional marginal cost to launch (if any)? Can we come up with designs?
...
So let's focus on Option 2 please, shall we? :-)

Thank you. I submit that Starship needs abort options but need not support every abort modality. Example: propulsive escape from an on-pad booster conflagration.

[meekGee]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

People did, for many years, right?

[laszlo]

Thank you. I submit that Starship needs abort options but need not support every abort modality. Example: propulsive escape from an on-pad booster conflagration.

The interesting question for me is that if the SS hardware supports in-flight aborts (similar to what just happened on the New Shepard) by just lighting its engines and flying away from the fireball, would a pad abort be free or nearly so? It would be the same situation, "just" zero altitude and zero velocity.  (I know, I'm also suspicious when someone says "just".)

But seriously, the lack of velocity means that SS would not be fighting supersonic or hypersonic drag which could help with the acceleration. Of course, the propellant would have less energy since it wouldn't be moving which could hurt acceleration. SS has demonstrated the ability to lift off from sea level, so it's not a totally new feature even though some of the parameters are pretty different. And there is, of course, the whole issue of having an SS primed to stage and fly away sitting on a fully fueled SH. It might actually be less safe than doing nothing.

Anyone have any thoughts on whether a pad abort feature would be "free" if an in-flight abort was already supported?

[Lee Jay]

Thank you. I submit that Starship needs abort options but need not support every abort modality. Example: propulsive escape from an on-pad booster conflagration.

The interesting question for me is that if the SS hardware supports in-flight aborts (similar to what just happened on the New Shepard) by just lighting its engines and flying away from the fireball, would a pad abort be free or nearly so? It would be the same situation, "just" zero altitude and zero velocity.  (I know, I'm also suspicious when someone says "just".)

But seriously, the lack of velocity means that SS would not be fighting supersonic or hypersonic drag which could help with the acceleration. Of course, the propellant would have less energy since it wouldn't be moving which could hurt acceleration. SS has demonstrated the ability to lift off from sea level,

Not on a full tank.

so it's not a totally new feature

Yeah, it kind of is.

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

Sorry, but you’re crossing the streams. The comparison is not between wildly different modes of transport, but among the various modes of failure within a mode of transport.

You said, "It's why nobody is handed a parachute when they board an airline flight.".

I answered that.

I did say that. And you answered by making a false comparison of airline safety to rocket safety.

Either we aren’t communicating well, or someone isn’t debating in good faith. I hope it’s the former.

The reason no one is handed a parachute when they get on an airliner is because they are 100,000 times safer than rockets.  If airliners were as safe as rockets, the airline industry wouldn't exist.

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

People did, for many years, right?

No.

Airliners were never anywhere near as unsafe as rockets are today.

[yg1968]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle. Pad abort has only ever been performed by a Soyuz, once. That's it.

None of the astronauts or cosmonauts killed in LV accidents would have been saved by a pad abort.

What if astronauts were on AMOS-6?

[dglow]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle. Pad abort has only ever been performed by a Soyuz, once. That's it.

None of the astronauts or cosmonauts killed in LV accidents would have been saved by a pad abort.

What if astronauts were on AMOS-6?

1. They weren't. It was a cargo mission. Different standards.

2. Had it been a crew mission, which it wasn't, they wouldn't have been on the vehicle. The AMOS-6 accident did not occur during a launch attempt.

[eriblo]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle. Pad abort has only ever been performed by a Soyuz, once. That's it.

None of the astronauts or cosmonauts killed in LV accidents would have been saved by a pad abort.

What if astronauts were on AMOS-6?

1. They weren't. It was a cargo mission. Different standards.

2. Had it been a crew mission, which it wasn't, they wouldn't have been on the vehicle. The AMOS-6 accident did not occur during a launch attempt.

3. SpaceX would presumably gone with the proven tanking procedure instead...

[dglow]

Either we aren’t communicating well, or someone isn’t debating in good faith. I hope it’s the former.

The reason no one is handed a parachute when they get on an airliner is because they are 100,000 times safer than rockets.  If airliners were as safe as rockets, the airline industry wouldn't exist.

Hopes dashed. You may have the last word. Cheers.

[meekGee]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

People did, for many years, right?

No.

Airliners were never anywhere near as unsafe as rockets are today.

Well the NTSB didn't keep statistics when airplanes were learning how to fly...  But SS will fly unmanned many more times than early airplanes were able to fly at all...  And initial crews will still be "Professional risk takers"...   But 10,000 flights will creep up on you faster than 14 F9 reuses did...

[Lee Jay]

To a point that's been made in other threads and hinted at above: history indicates we can get by without pad abort capability.

Shuttle's test flights, which had ejection seats, could not abort from the pad. It's never been needed by a US vehicle.

AMOS-6 could have used it.

Remind me which passengers were set to travel on AMOS-6.

That it hasn't happened yet is not evidence that it is not needed.  That justification has been used for centuries to create unsafe situations.  In other words, there's always the first time or "if it can happen it will happen".

That's reductionist thinking. The justification is an analysis of the flight and accident record of the world's launch vehicles. How many on-pad explosions have we witnessed? Few. Of a man-rated LV? Even fewer. Over the past three decades? Exactly.

It's just a cost per safety margin achieved equation. We can't design a system to perfectly protect in every eventuality, so we pick and choose wisely. It's why nobody is handed a parachute when they board an airline flight.

Airline flights are approximately 10^5 times more likely to end up returning safely than rocket launches.  If someone told you to get on a flight that was going to be 100,000 times more likely to crash than normal, would you do it without a parachute or other method of escape?

People did, for many years, right?

No.

Airliners were never anywhere near as unsafe as rockets are today.

Well the NTSB didn't keep statistics when airplanes were learning how to fly...  But SS will fly unmanned many more times than early airplanes were able to fly at all...

That statement is wholly unsupported.

And initial crews will still be "Professional risk takers"...   But 10,000 flights will creep up on you faster than 14 F9 reuses did...

I'll point out this post when that doesn't come close to happening.

[zodiacchris]

But can SS technically do a pad abort, given that the engines need to be pre-chilled before ignition, something that is only done during Stage 1 flight after launch on F9? Can SS fire it’s engine without having separated from the first stage, given that it sits on top of the booster with no place for the exhaust gas to go? I am not aware of any blow out panels in the Booster interstage. It seems to me that an attempted pad abort with these limitations would result in a massive explosion, rather than lift off.

What am I missing?