SpaceX Falcon 9 v1.1 - SES-8 - DISCUSSION THREAD

[StarryKnight]

Could someone refresh my memory; when was the last time a launch team extended an offical launch window set-up in advance with the Range? I vaguely remember we once extended a window to get a critical AF bird up but I don't remember any other. Yes the shuttle example is one where the short window was driven by mission constrainsts and they chose to change the constrainst. And a commerical bird usually have an orbital mechanics related sunlight contrainst for batteries/power issues. Maybe they had constrainst relieve from the customer already in their back pocket (in reserve), same with the Range support. I don't know the answer to that one.

It actually is very common for a launch vehicle provider to ask their customer about extending the launch window if they are working an issue that looks like might take them beyond the launch window duration to resolve. There are some missions in which this can't be done (e.g rendezvous with an orbiting spacecraft, direct injection into a Sun synchronous orbit, etc.). Also, some rockets, like Proton, do not use launch windows and either launch at the specific time or wait until the next day.

But missions to GTO often can give up a little margin on the power constraints that you mention or margin on other constraints (e.g. the Sun or moon getting near the edge of a sensor's field of view). The Sun is moving about 15 degrees per hour, so a 20 minute window extension means the Sun will be 5 degrees from what you considered worse case. So you have to ask yourself, is that 5 degree solar angle change really going to hurt you? What about 10 minutes for 2.5 degrees change?

[Avron]

What SpaceX has been repeatedly communicating is that they want to do things in a more iterative way and be much more efficient than "OldSpace" this way. Here, they have a customer who's clearly interested in making this better efficiency a reality so they are prepared to take quite a risk.

Eh... may I do a Jim.. "wrong" its Elon Musk's company, he is in the driving seat and its not "iterative way " is all based on first principles..  he is a disrupter, in the same league if not more so than Richard Branson.. 

its all about real space not really new space..  its not driven by bribes but  a different thinking - Musk "We have goals that are absurdly ambitious by any reasonable standard, but we’re going to make them happen. "

yes "absurdly ambitious "

[cro-magnon gramps]

check the times in the lower left hand corner...

edit, sorry, #8 doesn't have the clock... but the Strong Back was retracting/retracted

What is your point? The strongback is retracted minutes before launch.

#8 was to show progression, but the firing pic #9 shows two times, T-000 and the actual time of 38:58... then they correct to T-002, so just shows that without watching the actual clock, which was what they were going by, it would be easy to assume that the count down went to 0.... btw, my clumsy attempt to visually confirm what Chuck said... 

[Avron]

check the times in the lower left hand corner...

edit, sorry, #8 doesn't have the clock... but the Strong Back was retracting/retracted

What is your point? The strongback is retracted minutes before launch.

#8 was to show progression, but the firing pic #9 shows two times, T-000 and the actual time of 38:58... then they correct to T-002, so just shows that without watching the actual clock, which was what they were going by, it would be easy to assume that the count down went to 0.... btw, my clumsy attempt to visually confirm what Chuck said... 

I was thinking it was t-0, nice catch.. time flyes when you watch  it live.. HD on a mobile phone in a gym in downtown Toronto ,, the world has changed..  but 100% or fail still applies.

[yg1968]

Case of go fever.
 Shouldn't have started the terminal count if their data review wasn't complete.
Who's watching the rocket? And who is reviewing data?

They didn't succumb to it, but starting the countdown put some extra pressure on the review team.  It is only human nature. I am glad they didn't go and took the conservative path. 

I am wondering if Spacex shouldn't revaluate the length of the terminal count and try to shorten it. More complex vehicles have done it, the shuttle was 9 minutes vs the 13 of a F9.  It helps with launch window management.   It might have an affect on recycle time, but that is a trade that can be done.

During the countdown, the review team was asked "what their feeling was (on whether they could fix things in time for another attempt). They answered: "we don't have enough data to have a feeling one way or the other". So they may have started the countdown in case, the issues could be resolved in time. In SpaceX's defense, a lot of the other previous aborts were caused by non-issues. So it could have been another non-issue. But I am also glad that they took the safe and conservative approach. I wonder if Elon had a say in the final decision. 

[Avron]

Case of go fever.
 Shouldn't have started the terminal count if their data review wasn't complete.
Who's watching the rocket? And who is reviewing data?

They didn't succumb to it, but starting the countdown put some extra pressure on the review team.  It is only human nature. I am glad they didn't go and took the conservative path. 

I am wondering if Spacex shouldn't revaluate the length of the terminal count and try to shorten it. More complex vehicles have done it, the shuttle was 9 minutes vs the 13 of a F9.  It helps with launch window management.   It might have an affect on recycle time, but that is a trade that can be done.

During the countdown, the review team was asked "what their feeling was (on whether they could fix things in time for another attempt). They answered: "we don't have enough data to have a feeling one way or the other". So they may have started the countdown in case, the issues could be resolved in time. In SpaceX's defense, a lot of the other previous aborts were caused by non-issues. So it could have been another non-issue. But I am also glad that they took the safe and conservative approach. I wonder if Elon had a say in the final decision. 

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

[Herb Schaltegger]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

[llanitedave]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

Exactly.  That's why you hire experts.  Elon may be the public face of SpaceX, and he may be the one setting the corporate goals, priorities, and culture,  but it's the professionals who do the day to day work, and calling an abort is a decision for professionals.

[Avron]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

Exactly.  That's why you hire experts.  Elon may be the public face of SpaceX, and he may be the one setting the corporate goals, priorities, and culture,  but it's the professionals who do the day to day work, and calling an abort is a decision for professionals.

"Elon may be the public face of SpaceX,".. Elon musk is Spacex. Yes, he has hired the best and the abort call was a professional call  yes, but I would ask you to look at this a little closer, and you will find the designer at least.. you may find more..

[Lar]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

Exactly.  That's why you hire experts.  Elon may be the public face of SpaceX, and he may be the one setting the corporate goals, priorities, and culture,  but it's the professionals who do the day to day work, and calling an abort is a decision for professionals.

Elon bills himself as the Chief Rocket Designer so he may well have had some say in this. His tweet indicated some ownership of the decision...

Elon Musk ‏@elonmusk 28 Nov

We called manual abort. Better to be paranoid and wrong. Bringing rocket down to borescope engines ...

.... yes that could be the royal we but I read it as having some say.

[Avron]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

Exactly.  That's why you hire experts.  Elon may be the public face of SpaceX, and he may be the one setting the corporate goals, priorities, and culture,  but it's the professionals who do the day to day work, and calling an abort is a decision for professionals.

Elon bills himself as the Chief Rocket Designer so he may well have had some say in this. His tweet indicated some ownership of the decision...

Elon Musk ‏@elonmusk 28 Nov

We called manual abort. Better to be paranoid and wrong. Bringing rocket down to borescope engines ...

.... yes that could be the royal we but I read it as having some say.

since we are on tweets.. I think this one is the key tweet - "Increasing helium spin start pressure. Probably <50% chance of passing all aborts, but worth a try. Countdown resuming ..."

[clarkeo]

 I know I am coming across as a broken record , but its Elons company..  so yes its his call..

That does not follow, at all. Unless you have specific knowledge to the contrary, just because it's "his company" does not mean that every technical decision during the launch campaign flow is his to make.

Exactly.  That's why you hire experts.  Elon may be the public face of SpaceX, and he may be the one setting the corporate goals, priorities, and culture,  but it's the professionals who do the day to day work, and calling an abort is a decision for professionals.

Elon bills himself as the Chief Rocket Designer so he may well have had some say in this. His tweet indicated some ownership of the decision...

Elon Musk ‏@elonmusk 28 Nov

We called manual abort. Better to be paranoid and wrong. Bringing rocket down to borescope engines ...

.... yes that could be the royal we but I read it as having some say.

Can't we settle this pretty easily?! Multiple Launches Elon has been sitting in the control room (I can only assume the same is true for this launch). He doesn't seem to have an official position, but he does seem to have access to all the information so he can make informed decisions. I think its fair to say he probably has the final say or more accurately probably veto powers. I'm sure he doesn't understand every single thing as well as his top engineers but he seems to have a *very* workable understanding of his rocket.

[savuporo]

Not unlike a certain James T. K.

Small personal anecdote.
I had a tour in Tesla Fremont plant recently. Mr. Musk has a desk here in the middle of the factory floor that looks exactly likeevery other supply chain managrer desk there and when he comes by he works there. The only difference is that his desk phone is bigger and has more buttons. Also, when you call a supplier or partner from that phone, it gets immediately pickrd up, according to the guy that gave me the tour.

[Antares]

It was Tom, most likely, not Elon; or maybe Kevin or Will.

One man's cowboy is another man's expert who knows his vehicle, who has had dozens of hot fire aborts in north central Texas, enough to know there's no problem turning around and doing it again less than an hour later - but who also knows by heart, mind and hand the root cause and data signatures of every catastrophic test thereon.

One man's cautious scrub is another man's wasted day.  It's always safest to do nothing.  Who usually occupies that province and who usually takes the disruptive approach?

[ChrisWilson68]

I had to agree with Jim’s “Go Fever” comment from yesterday. They really wanted to launch and were trying to “cowboy” it... It was a bit gut wrenching to watch and I wonder how much risk the S/C owner was willing to take apart from extending the window. The safe practices Jim is aware of has been developed over several decades and was paid for dearly.

The practices developed over several decades are one way to achieve a particular degree of safety.  They are not necessarily the only way.  If everyone just says that because the one way has been found to do it we'll never look for alternatives then we'll never make progress.

I'm more interested in the reasons for the practices.  If there is a good reason a long-standing practice is better than an alternative, then by all means we should stick with it.  But it shouldn't be beyond questioning.

In the case we're talking about here, SpaceX started a new countdown before they had finished their analysis of the data from the previous scrub, knowing that if the analysis didn't say it was safe to launch they could still call it off.  From the outside, we have no way of knowing whether that was safe or not.  It's possible it distracted people from their normal countdown duties.  It's also possible the people involved in the analysis didn't have any active part in the countdown anyway.  So claiming, just based on the information we have, that SpaceX was doing something unsafe is unsubstantiated.

[MP99]

I had to agree with Jim’s “Go Fever” comment from yesterday. They really wanted to launch and were trying to “cowboy” it... It was a bit gut wrenching to watch and I wonder how much risk the S/C owner was willing to take apart from extending the window. The safe practices Jim is aware of has been developed over several decades and was paid for dearly.

The practices developed over several decades are one way to achieve a particular degree of safety.  They are not necessarily the only way.  If everyone just says that because the one way has been found to do it we'll never look for alternatives then we'll never make progress.

I'm more interested in the reasons for the practices.  If there is a good reason a long-standing practice is better than an alternative, then by all means we should stick with it.  But it shouldn't be beyond questioning.

In the case we're talking about here, SpaceX started a new countdown before they had finished their analysis of the data from the previous scrub, knowing that if the analysis didn't say it was safe to launch they could still call it off.  From the outside, we have no way of knowing whether that was safe or not.  It's possible it distracted people from their normal countdown duties.  It's also possible the people involved in the analysis didn't have any active part in the countdown anyway.  So claiming, just based on the information we have, that SpaceX was doing something unsafe is unsubstantiated.

There are two separate elements here.

1. What procedures they were following.
2. Whether they were getting a bit keen to launch.

The issue is whether 2 may have impacted the performance of 1, eg distraction as you mention, pressure to extend launch window, etc.

Cheers, Martin

[Chris Bergin]

For those not following the update thread as much as one should be....

NET Monday.

[LouScheffer]

In the case we're talking about here, SpaceX started a new countdown before they had finished their analysis of the data from the previous scrub, knowing that if the analysis didn't say it was safe to launch they could still call it off.  From the outside, we have no way of knowing whether that was safe or not.  It's possible it distracted people from their normal countdown duties.  It's also possible the people involved in the analysis didn't have any active part in the countdown anyway.  So claiming, just based on the information we have, that SpaceX was doing something unsafe is unsubstantiated.

It also depends on how much a last minute abort is part of their "normal" procedures.  Commercial airlines do something very similar thousands of times per day - they start a landing approach, not knowing if the weather is good enough at the runway.  At the last minute (or less) they need to either land, or abort and try again, or go elsewhere.    But the last minute abort is a standard procedure - they practice it routinely, it's marked on all the charts and checklists, on bigger planes there is hardware support (a "go-around" button that automates many of the needed configuration changes), pilots are tested to make sure they know it even if they've not needed it recently, and so on.  The net result is a safe system, since it's designed to cope with last-minute decisions.  (I have no idea if this applies to SpaceX, just that it's possible to make last minute decisions safely.)

[Avron]

Question ... how would oxygen get into the TEA-TEB lines?

[Jim]

It's also possible the people involved in the analysis didn't have any active part in the countdown anyway. 

These are people are usully the second set of eyes watching the vehicle during countdown and provide an engineering go in the count.  If they are doing the analysis, whoelse is watching the vehicle other than the operators.  Engineering watches all vehicles whether at VAFB, McGregor, Cape or Hawthorne.  Launch operators don't get as much experience as them and don't always see nuances.