SpaceX Falcon 9 : Intelsat 35e : July 5, 2017 : DISCUSSION

[cppetrie]

Just because they aren't revealing the problem to the world doesn't mean they don't know what it is. And just because they know which abort criteria was triggered doesn't mean they know the ultimate root cause or bug and have a fix for it. They'll tell us when they are good and ready to tell us.

[rickl]

For some reason my stream is like 7 seconds slow. Even the rebroadcast of it via spaceflight now was faster. I actually hit F5 and saw Chris G's ABORT post before I heard it on the stream.

Damn it YouTube, 7 seconds is everything!

The actual feed directly on SpaceX's webcast was about 7 minutes behind real-time.  The LD loop I have access to is instantaneous, which helps.

7 minutes, or 7 seconds?


Once it gets down to T-1 minute, I go to full screen with the webcast and watch that, rather than refreshing NSF.  I know that the webcast can lag quite a bit behind real time, and I don't want any spoilers.  Of course, if anything odd happens, I'll check out the NSF update thread immediately.

[testguy]

Just because they aren't revealing the problem to the world doesn't mean they don't know what it is. And just because they know which abort criteria was triggered doesn't mean they know the ultimate root cause or bug and have a fix for it. They'll tell us when they are good and ready to tell us.

I'm agreeing with you.  After all this IS rocket science!!!!!!

[Michael Baylor]

Elon Musk on Twitter, "We're going to spend the 4th doing a full review of rocket & pad systems. Launch no earlier than 5th/6th. Only one chance to get it right …"

Sounds like the Air Force is giving them one final shot before they begin the maintenance period. This really is crunch time. Even if SpaceX gets their stuff corrected, weather, or a wayward boat... Stuff happens!

[x15_fan]

I take that as they understand this problem and the last one but want to make sure nothing else crops up as three scrubs in a row is a bad way to go into shutdown (or worse). Or alternately some transient violation occurred that is not reproducing and causing some concern as to root cause.  I hope it is the former but door is open to the latter.

[Pete]

It's unfortunate that the launch of Intelsat 35e has been scrubbed at T-9 seconds twice in a row.

They should not be using that German logic chip in the rocket.
Its reading the countdown as: Thirteen,Twelve,Eleven,Ten, NEIN
And of course stops right there.


And on that same thought, Maybe it is best they are not planning a 4th of July launch.
Something about rocket launch and Fireworks just don't sit comfy together, when your fireworks is this big.

[Steven Pietrobon]

One thing I noticed while watching the SpaceflightNow feed (which is much appreciated, although its annoying when they switch over to Funky Music and no longer show the rocket!) is there is now only one big vent at about T-21 minutes. Previous launches showed regular venting all through the count. The first attempt was showing small venting during fueling, but the second attempt didn't show this at all. Perhaps the lighting conditions made viewing the fueling vents hard to see.

It could be that SpaceX is now piping those smaller vents elsewhere. This might be a safety thing, to prevent high concentrations of GOX (gaseous oxygen) building up around the rocket.

[Steven Pietrobon]

So is the update posted earlier by Steven from http://www.spacex.com/webcast not official?

Yes, it was official, taken from the SpaceX webcast page.

http://www.spacex.com/webcast

[Bubbinski]

When does the range stand down period end? If they end up having to go past Eastern Range closing what's the first date they can launch once the range repairs are finished?

[haywoodfloyd]

Since Elon Musk tweeted that the vehicle is healthy, I have to assume that they know what caused the second abort and are doing a top to bottom check to make sure it doesn't happen again.

[mn]

So is the update posted earlier by Steven from http://www.spacex.com/webcast not official?

Yes, it was official, taken from the SpaceX webcast page.

http://www.spacex.com/webcast

That's what I thought, my question was directed at Chris who wrote 'Not actually official yet'

[mn]

Since Elon Musk tweeted that the vehicle is healthy, I have to assume that they know what caused the second abort and are doing a top to bottom check to make sure it doesn't happen again.

If you know what cause the abort you don't need a "top to bottom check" to make sure it doesn't happen again. Unless they mean "top to bottom" of that particular sensor/setting

I believe "The vehicle is healthy" is just boilerplate text. (consider that this text or a variation of it seems to appear after every scrub - and not just SpaceX)

[cscott]

So is the update posted earlier by Steven from http://www.spacex.com/webcast not official?

Yes, it was official, taken from the SpaceX webcast page.

http://www.spacex.com/webcast

That's what I thought, my question was directed at Chris who wrote 'Not actually official yet'

SpaceX's PR person updating the website is not as official as a request and approval from the range.  Looks like PR was jumping the gun before the new time was actually approved by the range.

[SLC]

Since the rocket and the ground equipment worked perfectly together for the Static Fire, and the only difference now is the presence of the payload - could the problem be some sort of unforeseen control interaction with the payload?

During a normal launch, does the rocket GNC program ever ask the payload "Are you OK up there?" - or does the rocket just treat the payload as dead weight to be lifted?  (I know the payload may well be communicating with the client's ground monitoring equipment all the time, but I'm asking about direct rocket-to-payload signalling.)

[Jim]

 or does the rocket just treat the payload as dead weight to be lifted? 

[Joffan]

I have built and run test facilities with elaborate software that not only controlled the countdown but operation of the facility as well.  Because things were happening so rapidly many aborts were built into the software because human intervention would have been too unreliable and too slow.  The software necessarily knows why an abort is being called, that is the way it was programmed.  Whever we had an abort in the countdown or operation of the facility,the reason for the abort and the out of tolerance value was displayed on all computer screens for all to see.

I find it hard to believe that the folks at Spacex don't have a similar system. I'm having difficulty understanding why the reasons for the abort are not identified yet.  Perhaps a bad sensor is providing erroneous signal beginning at that point in the countdown.

Would it be typical for such systems to continue running through the sensor checks after an abort condition is detected? That is, would the system detect a second or third reason for abort, or just the first one?

[zubenelgenubi]

 or does the rocket just treat the payload as dead weight to be lifted? 

No, that's only how some NSF members treat the payload (the rocket is everything!).

[darkenfast]

There's a payload?

[Jarnis]

There's a payload?

There has to be. If there is nothing in the fairing, There would be potential issues... at least some throttling to avoid too high acceleration would be needed.

Ballast... Payload... same thing, right?

[Comga]

Jokes go here.