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

[newpylong]

Seriously? What kind of WDR did these guys have?

[DrLucky]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

[input~2]

59,000 people were watching the webcast!

[Lars_J]

Seriously? What kind of WDR did these guys have?

Hold the presses - A scrub! Unprecedented!

[russianhalo117]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

It cools and purges the payloads environment inside.
also there was another data cable that came off just before the hold call. it looked like they snagged on something during retraction.

[Avron]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

It cools and purges the payloads environment inside.
also there was another data cable that came off just before the hold call. it looked like they snagged on something during retraction.

It did look that way. Question, did the Strongback get fully retracted?

[WHAP]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

Most likely, yes.  If it was power or environmental conditioning and it was not a planned disconnect, the spacecraft could be in serious trouble without it. 

Talk on other threads that strongback was "stuck".  Is that really the case or are they just waiting to troubleshoot the umbilical problem, if it's a real problem?

[russianhalo117]

Elon's brother (@Kimbal on twitter) seems to be posting a few recent photos of the Falcon in its hangar, dated yesterday. A few highlights:

looks like they just modified the entire v1.0 TEL instead of build a new one.

[jimvela]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

Most likely, yes.  If it was power or environmental conditioning, the spacecraft could be in serious trouble without it. 

Talk on other threads that strongback was "stuck".  Is that really the case or are they just waiting to troubleshoot the umbilical problem, if it's a real problem?

I didn't see anything disconnect during the webcast.  If it did, that's very interesting.

If an electrical umbilical disconnected from the spacecraft, it would be a bad day... If the S/C is on battery power and has no way to go back to external or to shut off, this could be really, really bad.

Loss of an environmental control ductwork would also be bad if it feeds conditioned air into the fairing.

[AJA]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

Most likely, yes.  If it was power or environmental conditioning, the spacecraft could be in serious trouble without it. 

Talk on other threads that strongback was "stuck".  Is that really the case or are they just waiting to troubleshoot the umbilical problem, if it's a real problem?

These spacecraft limits would've also been factored into the launch window. i.e. the thermal capacity of the payload volume, and the battery depletion levels tolerated. (assuming some margin). If this disconnect would've happened on the first scrub today, I don't think they'd have needed to send someone out for the second scrub. Especially, given that it was night-time... Power, of course is unaffected by day or night, but I'd guess they can afford to be on S/C power for a decent amount of time (read ~an hour) - given it's only the computer that's running, and not the transmitters etc.

Seriously? What kind of WDR did these guys have?

Hold the presses - A scrub! Unprecedented!

We don't know yet... but if they scrubbed because of the venting issue (which they said was a non-issue), then it reflects poorly. Having said that... maybe something else, that was A-OK before, became the anomaly this time.

[Lars_J]

Elon's brother (@Kimbal on twitter) seems to be posting a few recent photos of the Falcon in its hangar, dated yesterday. A few highlights:

looks like they just modified the entire v1.0 TEL instead of build a new one.

No, it looks different: (if there are some common pieces, there aren't many)

[Avron]

Need a link to a replay of the retract..  anyone?

[WHAP]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

Most likely, yes.  If it was power or environmental conditioning, the spacecraft could be in serious trouble without it. 

Talk on other threads that strongback was "stuck".  Is that really the case or are they just waiting to troubleshoot the umbilical problem, if it's a real problem?

These spacecraft limits would've also been factored into the launch window. i.e. the thermal capacity of the payload volume, and the battery depletion levels tolerated. (assuming some margin). If this disconnect would've happened on the first scrub today, I don't think they'd have needed to send someone out for the second scrub. Especially, given that it was night-time... Power, of course is unaffected by day or night, but I'd guess they can afford to be on S/C power for a decent amount of time (read ~an hour) - given it's only the computer that's running, and not the transmitters etc.

I modified my post to clarify that this could be a concern if this umbilical disconnect was not a planned event.

Seriously? What kind of WDR did these guys have?

Hold the presses - A scrub! Unprecedented!

We don't know yet... but if they scrubbed because of the venting issue (which they said was a non-issue), then it reflects poorly. Having said that... maybe something else, that was A-OK before, became the anomaly this time.

It seemed that the vent occurred well before the hold call, but I believe that the vent was a result of the automatic abort due to something else being wrong, as an automatic step performed to start safing.

[Lars_J]

Was the vent really the cause for the scrub? My impression (could be wrong!) was that seemed to be related to the early disconnection of the fairing umbilicals.

[Avron]

Question, what umbilical connects to the flight computer.. ?

[Jim]

The lead flight controller also seemed to suggest that they'd cycle back to hold at T-13:00 while AVI (Avionics) worked

Launch conductor or controller.  Not flight

[Jim]

looks like they just modified the entire v1.0 TEL instead of build a new one.

It is a new one, the old one was scrapped

[Comga]

Need a link to a replay of the retract..  anyone?

Sure, but why are you asking, rather than just posting it or a link to it?

[DrLucky]

During the strongback retraction, at about T-4:00, I noticed an umbilical which connects to the fairing (and presumably the spacecraft) disconnect.  The other two umbilicals remained attached to 2nd and 1st stages.

In the event that they were to attempt a recycle, would that disconnect be a problem?  If not, what is the purpose of that umbilical?

Thanks,

DrLucky

Most likely, yes.  If it was power or environmental conditioning, the spacecraft could be in serious trouble without it. 

Talk on other threads that strongback was "stuck".  Is that really the case or are they just waiting to troubleshoot the umbilical problem, if it's a real problem?

These spacecraft limits would've also been factored into the launch window. i.e. the thermal capacity of the payload volume, and the battery depletion levels tolerated. (assuming some margin). If this disconnect would've happened on the first scrub today, I don't think they'd have needed to send someone out for the second scrub. Especially, given that it was night-time... Power, of course is unaffected by day or night, but I'd guess they can afford to be on S/C power for a decent amount of time (read ~an hour) - given it's only the computer that's running, and not the transmitters etc.

I recall hearing a female voice on the net, during the last recycle, responding something like "spacecraft still on internal power".  So when I saw the umbilical detach, I thought, "Ok, perhaps that's required during the many hours vertical but not during the window".  So it's entirely possible that the umbilical and/or venting are unrelated to the abort.  I brought it up because it's obviously not something you could reset with a fuelled LV on the pad, so I was wondering how that would work.

Anyone with professional knowledge aware of whether something like an unexpected disconnect would cause an automatic abort, or whether, as we saw, a controller calling "hold hold hold" on the net?

[Jim]

Anyone with professional knowledge aware of whether something like an unexpected disconnect would cause an automatic abort, or whether, as we saw, a controller calling "hold hold hold" on the net?

depends on the design of the system and which umbilical.  Could be either way.