** The Official Space Flight Thread - The Space Station and Beyond **

are all the audio telemetry from launch provided to NASA safety org so that they can review if risks and decisions were well judged,
how many people are actually involved in those - is Musk just an bystander
(it's not like the luxury of time they portray and voting amongst different sub-teams you see portrayed in Apollo13 say )
 
Have they released any post mortem yet?

Seems the mostly likely scenario is the disintegrating launch pad kicking up debris into the engines and taking some of them out....and then not being able to compensate sufficiently for the maneuvres before separation.
 
mid_gen said:
Have they released any post mortem yet?

Seems the mostly likely scenario is the disintegrating launch pad kicking up debris into the engines and taking some of them out....and then not being able to compensate sufficiently for the maneuvres before separation.
Click to expand...
I would say it’s a bit too soon for them to have finalised that. I doubt we will get anything detailed tbh. Probably a watered down PR statement.

After the last couple of pages I now see why companies don’t talk more about their engineering process, publicly at least. Which is a shame.
 
Grim5 said:
So even the self destruct system on starship is a failure, great
Click to expand...
Is it really? What do we know about the actual design intent of the flight termination system?

What we do know is it is an explosive manually attached to the outside of the craft a short period before the tanking process starts. And that is is designed to break the craft up in the event of loss of control.

Now any explosive system is going to have a non-zero chance of accidental initiation, very low but not zero. Human error etc. So do you want a system that instantaneously turns the craft into a fire ball attached when it will be on the ground and have over 3000 tonnes of propellant in it?

Just asking because you've already assessed it as a failure.
 
mid_gen said:
Have they released any post mortem yet?

Seems the mostly likely scenario is the disintegrating launch pad kicking up debris into the engines and taking some of them out....and then not being able to compensate sufficiently for the maneuvres before separation.
Click to expand...
I had wondered if they had a delayed relaaease because of some engines not starting. Even 2 engines will dramatically change the thrust to weight such that it may not lift at all. I wondered if some engines failed at ignition and then they had to increase the thrust on the others to compensate and that additional time at negaitve thrust to weight caused the much more pad damage than had been planned for.

So easy maths example 10 engines at 50% thrust gives you 500 up force. Your rocket weighs 400 down force. Net 100 up force to lift you off the pad.
Now 2 engines die at ignition and so your engines are providing 400 up (8 times 50%) and the craft 400 down force. You now need to throttle the remaining eninges up to 60% to get 480 up force. You lift off but more slowly and the time taken to decide to throttle up has been blasting downwards doing damage.

I might be entirely wrong it will be intersting to find out.
 
PlacidCasual said:
Is it really? What do we know about the actual design intent of the flight termination system?

What we do know is it is an explosive manually attached to the outside of the craft a short period before the tanking process starts. And that is is designed to break the craft up in the event of loss of control.

Now any explosive system is going to have a non-zero chance of accidental initiation, very low but not zero. Human error etc. So do you want a system that instantaneously turns the craft into a fire ball attached when it will be on the ground and have over 3000 tonnes of propellant in it?

Just asking because you've already assessed it as a failure.
Click to expand...

It took far too long to lose fuel, 15 seconds - if engines fail at low altitude that's enough time to hit the ground
 
Grim5 said:
It took far too long to lose fuel, 15 seconds - if engines fail at low altitude that's enough time to hit the ground
Click to expand...
If it was low enough that hitting the ground is a concern, then it is low enough that the shockwave and debris from the self destruction of the vessel (while in the air) pose a very big problem, arguably a large problem than letting it just hit the ground.
 
It will be interesting to see the FAA report. I can’t think they’ll be happy with any of the events and wonder what they’ll be requiring space x to do before they issue another launch license.
 
PlacidCasual said:
I had wondered if they had a delayed relaaease because of some engines not starting. Even 2 engines will dramatically change the thrust to weight such that it may not lift at all. I wondered if some engines failed at ignition and then they had to increase the thrust on the others to compensate and that additional time at negaitve thrust to weight caused the much more pad damage than had been planned for.

So easy maths example 10 engines at 50% thrust gives you 500 up force. Your rocket weighs 400 down force. Net 100 up force to lift you off the pad.
Now 2 engines die at ignition and so your engines are providing 400 up (8 times 50%) and the craft 400 down force. You now need to throttle the remaining eninges up to 60% to get 480 up force. You lift off but more slowly and the time taken to decide to throttle up has been blasting downwards doing damage.

I might be entirely wrong it will be intersting to find out.
Click to expand...
I think individual thrust will be computer controlled. A human is simply not quick enough or precise enough, to control that many engines.
If you have an asymmetric number of engines you will need to increase the thrust on one side more than the other to ensure that your centre of thrust (Is that right term?) is inline with your centre of gravity.

One thing I noticed with the damage to the launch pad is that it is not uniformly circular. Its mostly on on side of the pad. It could have been caused by one side having more thurst than the other (maybe because of the damage they had to compensate for the missing engine) or when it lifted off and was translating sideways that caused the non-uniform damage of the launchpad. It could also be that the concrete did not have consistent properties throughout the structure.
 
Last edited:
I'm yet to watch the Scott manely video, so maybe he mentions it, but they will be using the hover slam(suicide burn?) to land on mars. That will probably throw any debris into the surronding area at a minimum, worst case it digs the ground up at the landing site and causes an unstable landing.

I believe starship is going to the moon first as part of the artemis program, so that will be a good testing ground.
 
We saw starship launch in Earth gravity and by and large the concrete survived, but it does raise some significant questions about Starship as a Mars Lander even under 1/3rd Earth gravity. It may end up being an into orbit reusable delivery system at least for the foresseable future. HLS Starship will operate under less gravity and so the high up engines may be sufficient. I guess we'll find out. They have to do a dry run to the surface I believe,
 
Just watched Wai's video on the aftermath, one thing for sure, it's gonna be a while before that is used again. Not only do they have serious damage to repair but all parts of stage 0 will need inspecting and testing. Then of course its abundantly clear that a flame diverter is absolutely required.
 
You must log in or register to reply here.
Back
Top Bottom