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SpaceX Vehicles and Missions => SpaceX Missions Section => Topic started by: Chris Bergin on 04/19/2016 02:44 pm

Title: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Chris Bergin on 04/19/2016 02:44 pm
Thought we had a thread for this one already, anyway:

S1 is at McGregor:
https://www.nasaspaceflight.com/2016/04/falcon-9-booster-reuse-testing-ksc/ (https://www.nasaspaceflight.com/2016/04/falcon-9-booster-reuse-testing-ksc/)

Resources:

SpaceX News Articles from 2006 (Including numerous exclusive Elon interviews):
http://forum.nasaspaceflight.com/index.php?topic=21862.0 (http://forum.nasaspaceflight.com/index.php?topic=21862.0)

SpaceX News Articles (Recent):
http://www.nasaspaceflight.com/tag/spacex/ (http://www.nasaspaceflight.com/tag/spacex/)

=--=

SpaceX GENERAL Forum Section:
http://forum.nasaspaceflight.com/index.php?board=45.0 (http://forum.nasaspaceflight.com/index.php?board=45.0) - please use this for general questions NOT specific to this mission.

SpaceX MISSIONS Forum Section:
http://forum.nasaspaceflight.com/index.php?board=55.0 (http://forum.nasaspaceflight.com/index.php?board=55.0) - this section is for everything specific to SpaceX missions.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ZachS09 on 04/20/2016 12:33 am
On the SpaceX Manifest thread, it says that the launch date is May 3rd. Could SpaceX pull off two launches in five days?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Galactic Penguin SST on 04/20/2016 03:19 am
I don't think the satellites have been delivered to the launch site yet. Is that correct?

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 04/20/2016 11:50 am
Am I right in saying that these are the two SEP-powered spacecraft that only need to be launched into LEO?

On the SpaceX Manifest thread, it says that the launch date is May 3rd. Could SpaceX pull off two launches in five days?

I'd add at least seven days to that, minimum but stranger things have happened, assuming that the booster is already ready for delivery.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rocx on 04/20/2016 12:23 pm
Am I right in saying that these are the two SEP-powered spacecraft that only need to be launched into LEO?

I don't think so. Letting an SEP satellite raise itself from LEO to GEO would take a long time, and much of that time in the Van Allen belts. At a minimum the Falcon 9 would launch it to an apogee significantly above the Van Allen belts.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Chris Bergin on 04/20/2016 12:56 pm
On the SpaceX Manifest thread, it says that the launch date is May 3rd. Could SpaceX pull off two launches in five days?

I doubt that May 3 date will hold for this one. It's simply a case where (non-CRS, because the ISSP work out VV schedules in advance) mission dates pan out one at a time. Concentration is on JCSAT-14, then we'll know about this next one.

Also pretty sure five days is not a doable turnaround on the same pad yet.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Okie_Steve on 04/20/2016 03:04 pm
So, give the wildly much too optimistic assumption of two building, two rockets and two complete crews form SpaceX and satellite vendors to work on them, what is the rate limiting work on the pad itself? I'm guessing the umbilicals have to be replaced and RP-1 and chilled LOX talks have to be brought back up to capacity, what else?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 04/20/2016 03:14 pm
So, give the wildly much too optimistic assumption of two building, two rockets and two complete crews form SpaceX and satellite vendors to work on them, what is the rate limiting work on the pad itself? I'm guessing the umbilicals have to be replaced and RP-1 and chilled LOX talks have to be brought back up to capacity, what else?

One building, one erector and one pad.  Only one set of stages can fit in the SLC-40 HIF at a time.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lar on 04/20/2016 03:27 pm
So, give the wildly much too optimistic assumption of two building, two rockets and two complete crews form SpaceX and satellite vendors to work on them, what is the rate limiting work on the pad itself? I'm guessing the umbilicals have to be replaced and RP-1 and chilled LOX talks have to be brought back up to capacity, what else?

One building, one erector and one pad.  Only one set of stages can fit in the SLC-40 HIF at a time.
Is it pretty much impossible to do "most of the work" in the 39a HIF and then transfer? I'm thinking once they mate the second stage they''re not going to move from one HIF to another...?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: GreenShrike on 04/20/2016 03:37 pm
Would it be practical to prep Eutelsat/ABS in LC-39A's HIF while JCSAT is tying up SLC-40?

Actually I guess CRS-8's booster will be occupying 39A for a while, but more generally, if LC-39A isn't in the middle of a launch campaign, would it be practical to use its HIF to parallel process a second F9 and/or payload, and move it over to SLC-40 once the first F9 is launched and 40's HIF is clear?

I imagine in the future with, say, 4 Dragon launches (3 cargo, 1 crew) and some number of additional NASA, AF or other gov't payloads, 39A will be fairly busy and its facilities won't be sitting idle for long stretches. And if they are idle, then SpaceX could just launch a commercial sat from 39A and not bother with transferring the vehicle to 40, so I guess this current period is an anomaly and using 39A to prep a launch for 40 wouldn't be a normal procedure.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 04/20/2016 04:43 pm
Is it pretty much impossible to do "most of the work" in the 39a HIF and then transfer? I'm thinking once they mate the second stage they''re not going to move from one HIF to another...?

They already  have Building AO to process stages before going to the SLC-40 HIF.  Going to 39 isn't going to provide any more advantages.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 04/20/2016 04:45 pm
Would it be practical to prep Eutelsat/ABS in LC-39A's HIF while JCSAT is tying up SLC-40?

Actually I guess CRS-8's booster will be occupying 39A for a while, but more generally, if LC-39A isn't in the middle of a launch campaign, would it be practical to use its HIF to parallel process a second F9 and/or payload, and move it over to SLC-40 once the first F9 is launched and 40's HIF is clear?

I imagine in the future with, say, 4 Dragon launches (3 cargo, 1 crew) and some number of additional NASA, AF or other gov't payloads, 39A will be fairly busy and its facilities won't be sitting idle for long stretches. And if they are idle, then SpaceX could just launch a commercial sat from 39A and not bother with transferring the vehicle to 40, so I guess this current period is an anomaly and using 39A to prep a launch for 40 wouldn't be a normal procedure.

They don't move completed vehicles between facilities.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Saabstory88 on 04/20/2016 05:56 pm
Would it be practical to prep Eutelsat/ABS in LC-39A's HIF while JCSAT is tying up SLC-40?

Actually I guess CRS-8's booster will be occupying 39A for a while, but more generally, if LC-39A isn't in the middle of a launch campaign, would it be practical to use its HIF to parallel process a second F9 and/or payload, and move it over to SLC-40 once the first F9 is launched and 40's HIF is clear?

I imagine in the future with, say, 4 Dragon launches (3 cargo, 1 crew) and some number of additional NASA, AF or other gov't payloads, 39A will be fairly busy and its facilities won't be sitting idle for long stretches. And if they are idle, then SpaceX could just launch a commercial sat from 39A and not bother with transferring the vehicle to 40, so I guess this current period is an anomaly and using 39A to prep a launch for 40 wouldn't be a normal procedure.

They don't move completed vehicles between facilities.

That makes me wonder, what kind of flight rate would have to be occurring before their current facilities would become a bottleneck?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ronsmytheiii on 05/03/2016 08:23 pm
Corporate video:

https://www.youtube.com/watch?v=85wct53jPI0

Edit:

ABS 2A coverage and tech info

http://www.absatellite.com/satellite-fleet/?sat=abs2a

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: John Alan on 05/09/2016 05:56 pm
http://forum.nasaspaceflight.com/index.php?topic=40231.msg1531465#msg1531465 (http://forum.nasaspaceflight.com/index.php?topic=40231.msg1531465#msg1531465)

My opinion... this one will go expendable... see above post I made in the Manifest thread...
I may be wrong... just my opinion...  ;)

On edit much later... I am likely wrong on this.. not as heavy as I was led to believe..
However... I still believe SpaceX will go expendable on anything above 5250kg-ish in the short term...
Just an opinion...  ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 05/12/2016 06:05 pm
Tweet from Stephen Clark (https://twitter.com/StephenClark1/status/730800831008624640)
Quote
Eutelsat: Launch of Eutelsat 117 West B telecom satellite on SpaceX Falcon 9 with ABS 2A co-passenger still expected before the end of June.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 05/12/2016 07:13 pm
http://forum.nasaspaceflight.com/index.php?topic=40231.msg1531465#msg1531465 (http://forum.nasaspaceflight.com/index.php?topic=40231.msg1531465#msg1531465)

My opinion... this one will go expendable... see above post I made in the Manifest thread...
I may be wrong... just my opinion...  ;)

On edit much later... I am likely wrong on this.. not as heavy as I was led to believe..

The manifest list by starhawk92 calls it 4200 kg, which is lighter than JCSAT-14 by 500 kg or so. Good news for the landing attempt.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: FutureSpaceTourist on 05/13/2016 09:00 am
Eutelsat have had a briefing (investor's call?) this morning. Still showing Eutelsat 117WB as Q2 2016 (ie June given Thaicom 8 is next in late May):

Quote
Peter B. de Selding ‏@pbdes 10m10 minutes ago

Here's Eutelsat launch plan. Add 115 West B, launched for LatAm. Co believes in HTS for consumer brdbnd only.

https://twitter.com/pbdes/status/731043082981015552 (https://twitter.com/pbdes/status/731043082981015552)

Also some launches in 2018/19 yet to be announced.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: FutureSpaceTourist on 05/13/2016 10:28 am
Here's a bit more specific update on launch date:

Quote
Peter B. de Selding ‏@pbdes 21m21 minutes ago

Eutelsat says SpaceX launch of its 117W B sat (w/ ABS-2A) in mid-June. This is 2d pair of Boeing all-elect sats riding together on Falcon 9.

https://twitter.com/pbdes/status/731063198305140736 (https://twitter.com/pbdes/status/731063198305140736)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: oldAtlas_Eguy on 05/13/2016 09:33 pm
The exact date for a mid June launch would depend on both the Thiacom and CRS9 dates. If CRS 9 is holding to a 27 June date that would put the Eutelsat/ABS ~11 June. If CRS 9 has moved out into July then I would peg the date as ~18 June.

June looks to be a very busy month with 10 launches worldwide. And 3 of those SpaceX (maybe).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cro-magnon gramps on 05/14/2016 01:26 am
The exact date for a mid June launch would depend on both the Thiacom and CRS9 dates. If CRS 9 is holding to a 27 June date that would put the Eutelsat/ABS ~11 June. If CRS 9 has moved out into July then I would peg the date as ~18 June.

June looks to be a very busy month with 10 launches worldwide. And 3 of those SpaceX (maybe).

If we figure that perhaps SpaceX can launch Thaicom-8 on the 26th / 27th of May, and the CRS 9 goes off on June 27th, then a launch from KSC in the middle is not impossible... but wait, there is also the possibility of a launch out of Vandenberg for Falcon 9 • Formosat 5 & Sherpa; will this throw a spanner into the works?? ???

Only if Thaicom-8 slips to June then we might have a problem. How big an if is that??  :-\

edit clarified that Thaicom-8 is on 26th / 27th
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 05/14/2016 01:56 am
Nothing is launching from Vandenberg in June.  The Spacex pad is being worked on right now and the whole launch range is down until probably August.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cro-magnon gramps on 05/14/2016 02:29 am
Nothing is launching from Vandenberg in June.  The Spacex pad is being worked on right now and the whole launch range is down until probably August.

Thx, was not aware, just going on the launch list at SpaceFlightNow page... that makes June easier for SpaceX...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: oldAtlas_Eguy on 05/14/2016 05:37 pm
Nothing is launching from Vandenberg in June.  The Spacex pad is being worked on right now and the whole launch range is down until probably August.

Thx, was not aware, just going on the launch list at SpaceFlightNow page... that makes June easier for SpaceX...
The range assets being moved is the control center. All hardware will have been removed from their current location/building by 1 June. The remain tasks are installation/upgrades and validation and verification of comm/control links. That last item is the one that has a highly variable time length as long as a couple of months. But don't count out a SpaceX launch in end of June or early July just yet. Also Iridium and SpaceX would not have publicly said they will launch in July if they knew that it was impossible due to no range support.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: bstrong on 05/14/2016 06:06 pm


Also Iridium and SpaceX would not have publicly said they will launch in July if they knew that it was impossible due to no range support.

Especially since the CEO of Iridium said it on an earnings call, which would be criminal if he knew it was impossible.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 05/14/2016 06:36 pm


Also Iridium and SpaceX would not have publicly said they will launch in July if they knew that it was impossible due to no range support.

Especially since the CEO of Iridium said it on an earnings call, which would be criminal if he knew it was impossible.

SpaceNews article from late April: (http://spacenews.com/iridium-says-2nd-generation-constellation-ready-to-launch-with-spacex-starting-in-july/)
Quote
McLean, Virginia-based Iridium said the launch date could slip by a few weeks, depending on SpaceX’s management of its busy manifest.
It's a rocket launch, so no one is going to promise an exact date.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: bstrong on 05/14/2016 07:58 pm


Also Iridium and SpaceX would not have publicly said they will launch in July if they knew that it was impossible due to no range support.

Especially since the CEO of Iridium said it on an earnings call, which would be criminal if he knew it was impossible.

SpaceNews article from late April: (http://spacenews.com/iridium-says-2nd-generation-constellation-ready-to-launch-with-spacex-starting-in-july/)
Quote
McLean, Virginia-based Iridium said the launch date could slip by a few weeks, depending on SpaceX’s management of its busy manifest.
It's a rocket launch, so no one is going to promise an exact date.
Of course. He didn't promise it would happen then. But he would not have said it was planned to happen then if he knew it was impossible due to the range closure.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rockets4life97 on 05/20/2016 01:21 am
Spaceflight Now is reporting that the current targeted launch date is June 16.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: DatUser14 on 05/28/2016 12:59 am
A wrapped horizontal core spotted at CCAFS, do we know if 026 has officially arrived, or could this be 021 or 024 leaving?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: deruch on 05/28/2016 03:00 am
A wrapped horizontal core spotted at CCAFS, do we know if 026 has officially arrived, or could this be 021 or 024 leaving?
Someone in one of the other threads was claiming to have just seen a core in Leesburg, FL. 

falcon sighting in leesburg florida really awsome delayed me but was worth it got pics will post later
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 05/28/2016 04:58 am
A wrapped horizontal core spotted at CCAFS, do we know if 026 has officially arrived, or could this be 021 or 024 leaving?
Someone in one of the other threads was claiming to have just seen a core in Leesburg, FL. 

falcon sighting in leesburg florida really awsome delayed me but was worth it got pics will post later

Might this be it?

https://www.youtube.com/watch?v=ajpsfxdvP34 (https://www.youtube.com/watch?v=ajpsfxdvP34)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: matthewkantar on 05/29/2016 12:10 am
This may have been discussed elsewhere, can anyone guess why would they use black material to wrap the stages for the road? Would think that would be hard on the composite parts of the rocket.

Matthew
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: speedevil on 05/29/2016 12:18 am
This may have been discussed elsewhere, can anyone guess why would they use black material to wrap the stages for the road? Would think that would be hard on the composite parts of the rocket.

In the open air, black material won't get to 100C.
This is well under the temperature of concern of the composites used - they have to take considerable reentry heating, and in some cases flame!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lee Jay on 05/29/2016 12:54 am
This may have been discussed elsewhere, can anyone guess why would they use black material to wrap the stages for the road? Would think that would be hard on the composite parts of the rocket.

Matthew

Generally, black plastics are much more immune to UV degradation than white plastics are.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: saliva_sweet on 06/02/2016 08:21 am
I've been pondering whether SpaceX might be thinking about making this flight expendable. I found the last minute unexplained switch with thaicom right after the surprise recovery of jcsat core quite interesting (maybe they decided to change the configuration/trajectory). Do they, at this time, want any more cores from high energy reentries with questionable reuse potential? They're already piling up and starting to look ridiculous.

These sats are all electric and every last meter per second dV translates to money in a fairly straightforward way and they could negotiate more money out of the customer for a better GTO. I believe the previous ABS/Eutelsat flight already used minimum residual shutdown for max performance. Flying this one expendably would make a lot of sense, only thing is Elon might forbid this for strategic reasons.

edit: typos
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: nisse on 06/02/2016 08:57 am
I've been pondering whether SpaceX might be thinking about making this flight expendable. I found the last minute unexplained switch with thaicom right after the surprise recovery of jcsat core quite interesting (maybe they decided to change the configuration/trajectory). Do they, at this time, want any more cores from high energy reentries with questionable reuse potential? They're already piling up and starting to look ridiculous.
Why not? Even if the stages are damaged beyond repair the engines might still be possible to reuse?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lar on 06/02/2016 01:29 pm
I agree that the discussion belongs on a reuse thread.
All of these seem candidates...
   
Refurbishment of Used Stages/Vehicles
Reusability effect on costs 
Status of first F9 S1 re-use   
Fairing reuse     
Possible F9 S1 changes to reduce GTO booster recovery damage 

Edit: I decided (with some input, thanks!) that  Refurbishment of Used Stages/Vehicles was the best choice.
Posts were moved to  http://forum.nasaspaceflight.com/index.php?topic=39167
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Norm38 on 06/03/2016 01:29 pm
Do they, at this time, want any more cores from high energy reentries with questionable reuse potential?

They haven't reached operational status yet.  They just banged up a leg pretty good on landing, still prototyping.  Thus, if they have the fuel to land, they'll land and get more data.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Robotbeat on 06/03/2016 08:16 pm
Do they, at this time, want any more cores from high energy reentries with questionable reuse potential?

They haven't reached operational status yet.  They just banged up a leg pretty good on landing, still prototyping.  Thus, if they have the fuel to land, they'll land and get more data.
Sounds like they used up a replaceable consumable on the leg, the crush core, not "banged up a leg pretty good." And yeah this made for an awkward ride back to shore, but still.

Anyway, I agree with your point. Every flight that they don't attempt recovery on is one more flight extra they need to perfect recovery.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/03/2016 09:55 pm
Officially moved up to June 14.

Obviously the end times are near when launch Windows move left on a schedule. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mme on 06/03/2016 10:09 pm
SpaceX Tweet (https://twitter.com/SpaceX/status/738832343725576192)
Next launch targeting June 14 from Cape Canaveral – 45 minute launch window opens at 10:32am ET, 2:32pm UTC
(https://pbs.twimg.com/media/CkDcGNMUkAAMAZx.jpg:orig)
45 minute window is interesting.  I don't think that allows enough time to unload and reload propellent but it does give them some leeway on when propellent loading starts.  Plus how ever long they can allow propellent to warm post loading but I think that is a pretty short time.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: king1999 on 06/04/2016 01:11 am
45 minutes may be enough to chase away a boat!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CJ on 06/04/2016 09:43 am
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gospacex on 06/04/2016 11:03 am
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)

Another sign of how amateurish SpaceX is. Schedule slips left and right!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Barmaglot on 06/04/2016 11:11 am
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)

Just to put it in perspective, it was scheduled for Q4-15, then 03-16, then 04-16, then 03-05-2016, then 16-06-16, and finally 14-06-16. So, yeah, two days of advancement totally make up for eight months of schedule slips.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Mongo62 on 06/04/2016 12:20 pm
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)

Just to put it in perspective, it was scheduled for Q4-15, then 03-16, then 04-16, then 03-05-2016, then 16-06-16, and finally 14-06-16. So, yeah, two days of advancement totally make up for eight months of schedule slips.

What's your point? Schedule slips to the right are common (even for non-SpaceX launches), but changes to the left are virtually unheard of.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: macpacheco on 06/04/2016 01:52 pm
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)

Another sign of how amateurish SpaceX is. Schedule slips left and right!

Because SpaceX managed to do something faster, somehow they're amateurs. Oh they don't have a lot of fat in their schedules. They don't accept putting some padding in just in case.
I my opinion it just shows how serious they are about fulfilling their manifest.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: woods170 on 06/04/2016 03:30 pm
I thought this was scheduled for late June? It's now June 14th?

Did we just see a schedule slip to the left, rather than the right? If so, that's the first time I've ever seen that, from anyone. 8)

Another sign of how amateurish SpaceX is. Schedule slips left and right!

Because SpaceX managed to do something faster, somehow they're amateurs. Oh they don't have a lot of fat in their schedules. They don't accept putting some padding in just in case.
I my opinion it just shows how serious they are about fulfilling their manifest.
You obviously didn't get the joke.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/04/2016 05:55 pm
SpaceX Tweet (https://twitter.com/SpaceX/status/738832343725576192)
Next launch targeting June 14 from Cape Canaveral – 45 minute launch window opens at 10:32am ET, 2:32pm UTC
(https://pbs.twimg.com/media/CkDcGNMUkAAMAZx.jpg:orig)

Are those two spacecraft really the twins that they look like?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/04/2016 06:20 pm
Yes. The Boeing 702SP electric propulsion commsats are designed for a dual manifest capability. F9 launched another pair last year.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lar on 06/04/2016 07:08 pm
SpaceX Tweet (https://twitter.com/SpaceX/status/738832343725576192)
Next launch targeting June 14 from Cape Canaveral – 45 minute launch window opens at 10:32am ET, 2:32pm UTC
(https://pbs.twimg.com/media/CkDcGNMUkAAMAZx.jpg:orig)

both birds look impressive...  SWEET that we have a date pulled in. That's not amateurish it's awesome. Even 2 days is something.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: The Amazing Catstronaut on 06/04/2016 08:29 pm
Looks like the world's biggest boom box they're launching into space there.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: BruceM on 06/05/2016 06:26 pm
Officially moved up to June 14.

Obviously the end times are near when launch Windows move left on a schedule.

Great to see this!

Wondered if anyone has thoughts on why the move.

Possibilities:
1. Range availability?  (SFN shows a Delta 4 launch on 6/9 and an Atlas 5 launch on 6/24)
2. Did the customer just call them up and say, "How about moving our launch up a couple of days?"  :)
3. As they were preparing for the launch they just happened to find themselves with a couple of free days with nothing to do so they decided to move up the launch?   :D
4. Next SX launch at SLC 40 appears to be CRS-9 on 7/16.  Does this move result in just enough time to slide in another launch before CRS-9?  (Starhawk92's schedule shows AMOS-6 and JCSAT-16 set for August but didn't hear anything about them wanting to move up).   ;D

Probably other possibilities as well.

Would be especially interesting to hear thoughts from anyone "in the know" about how this decision might have been made but glad for all thoughts.

Thanks!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: alexterrell on 06/05/2016 07:00 pm
Looks like the world's biggest boom box they're launching into space there.

Giant stereo speakers in space! Save on the broadcasting and reassembling the signal bit :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: baldusi on 06/05/2016 07:03 pm
The comm sat processing is usually 30days. If they would interleave a launch, we should have seen the bird arrive at the Cape already. Unless CRS-9 is delayed in which case the bird might be arriving this week.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: russianhalo117 on 06/05/2016 07:47 pm
The comm sat processing is usually 30days. If they would interleave a launch, we should have seen the bird arrive at the Cape already. Unless CRS-9 is delayed in which case the bird might be arriving this week.
Valid as of two weeks ago Monday, is that shipping reviews and packing in the shipping containers has been completed for both AMOS-6 and JCSAT-16 and there mobile GSE. I have found no public indication yet that the satellites have arrived at CCAFS for processing at either offline or online processing facilities on and off of base.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Zed_Noir on 06/06/2016 05:14 am
Slightly OT question. Can you stacked 3 Boeing 702 SP birds together for launch?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: manoweb on 06/06/2016 12:41 pm
You obviously didn't get the joke.
Something that happens a lot even to native speakers.
And I think his English is a LOT better than our Portugese.

But this is not a grammar issue, it's a semantic one, so the native language is less relevant. I am also not a native speaker but it was extremely clear it was a "nerd" joke.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/06/2016 02:29 pm
I'm excited that we are almost at the static fire and we are 8 days out for the next launch and that the last booster is just getting hauled off to the hanger.

It's a nice little flow they are establishing.  With ASDS landings it looks like it will be hard to get much better than a 17 day cycle without adding another ASDS.
1) 4-5 days to get on station
2) ? days to catch the rocket (depending on launch scrubs)
3) 4-5 days return to port
4) 2-3 days unload rocket
5) ? days to resupply and service
5) Repeat
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lar on 06/06/2016 04:56 pm
Steps 4 and 5 are where I expect to see schedule improvement... Can't do much about how fast they can travel out and back, but they are already showing improvement at unload time I think?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AncientU on 06/06/2016 05:31 pm
Steps 4 and 5 are where I expect to see schedule improvement... Can't do much about how fast they can travel out and back, but they are already showing improvement at unload time I think?

Didn't they offload this one within 8-10 hours?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lar on 06/06/2016 05:42 pm
Steps 4 and 5 are where I expect to see schedule improvement... Can't do much about how fast they can travel out and back, but they are already showing improvement at unload time I think?

Didn't they offload this one within 8-10 hours?
(*the last one.. this one hasn't flown yet :) *)

Yes. The total cycle time was hurt by waiting around outside port before entering but the unload itself was the fastes so far I think. Probably we are veering a bit off topic, multiple threads are now discussing the expected fastest cycle time, etc...  dunno which is best. Probably the overall ASDS thread?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: dante2308 on 06/07/2016 11:52 am


Perhaps with GTO but there is also RTLS and JRTI. On top of that, they might be returning more cores than they can validate at this stage.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/07/2016 01:36 pm
Cross-posting the FCC permit:


FCC transmitter permit application for the next mission:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=71187&RequestTimeout=1000

ASDS position coordinates are the same as for Thaicom 8, so it looks like SpaceX has found the "sweet spot" for GTO mission landing attempts.

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: tleski on 06/09/2016 01:40 am
I don't think it was posted before, probably not good enough for the update thread.
EUTELSAT 117 West B information brochure from Eutelsat's website:
http://www.eutelsat.com/en/satellites/future-satellites/EUTELSAT-117WB.html

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: EngrDavid on 06/09/2016 11:53 pm
With the delta IV launch delayed, will this next launch get pushed back too? Accordingly, will they be able to perform the static fire with the delta IV still on its pad?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Thorny on 06/10/2016 02:03 pm
With the delta IV launch delayed, will this next launch get pushed back too? Accordingly, will they be able to perform the static fire with the delta IV still on its pad?

I think this Delta IV has been on the pad since March, so yes.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: baldusi on 06/10/2016 03:22 pm
With the delta IV launch delayed, will this next launch get pushed back too? Accordingly, will they be able to perform the static fire with the delta IV still on its pad?

I think this Delta IV has been on the pad since March, so yes.
Issue for other pads was when SpaceX hadn't proven the design, and SLC-4E and W are pretty close. Now it is a completely different risk. They even do some hotfires with their payload on top.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kansan52 on 06/10/2016 04:35 pm
It has been stated here that it takes two day to reset the range. So, if the Delta launches the 11th (a Saturday) will the 2 days be the 12th (Sunday) and the 13th (Monday) so a Falcon launch on the 14th (Tuesday) be possible?

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/10/2016 05:30 pm
It has been stated here that it takes two day to reset the range. So, if the Delta launches the 11th (a Saturday) will the 2 days be the 12th (Sunday) and the 13th (Monday) so a Falcon launch on the 14th (Tuesday) be possible?

Back in the day NASA used to launch a Atlas and Titan-II on the same day for the Gemini program.  I guess times have changed. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hans_ober on 06/10/2016 05:31 pm
It has been stated here that it takes two day to reset the range. So, if the Delta launches the 11th (a Saturday) will the 2 days be the 12th (Sunday) and the 13th (Monday) so a Falcon launch on the 14th (Tuesday) be possible?

Any idea why it takes so long? How complicated is the equipment they have?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/10/2016 05:49 pm
It has been stated here that it takes two day to reset the range. So, if the Delta launches the 11th (a Saturday) will the 2 days be the 12th (Sunday) and the 13th (Monday) so a Falcon launch on the 14th (Tuesday) be possible?

Any idea why it takes so long? How complicated is the equipment they have?

Jim will be able to tell us exactly.

But I thought was because they are working with equipment from the Kennedy Administration era and that they haven't manned up to modernize the range.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jarnis on 06/10/2016 05:50 pm
It has been stated here that it takes two day to reset the range. So, if the Delta launches the 11th (a Saturday) will the 2 days be the 12th (Sunday) and the 13th (Monday) so a Falcon launch on the 14th (Tuesday) be possible?

Any idea why it takes so long? How complicated is the equipment they have?

The question you should be asking instead is "How old is the equipment they have?"...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: yokem55 on 06/10/2016 05:52 pm
Being a national security mission, could the Delta heavy launch bump SpaceX from their 6-14 slot? Or would ULA stand down for SpaceX to launch?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kansan52 on 06/10/2016 05:54 pm
No, no direct knowledge of why it takes so long. Other posts leads me to believe that the range equipment is complex and it take hands on to make some of the changes. But no hands on verification.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/10/2016 05:55 pm
For example: http://www.cnbc.com/2016/05/25/us-military-uses-8-inch-floppy-disks-to-coordinate-nuclear-force-operations.html

Yes, 8 inch floppies.

Maybe the eastern range still uses punch cards.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: watermod on 06/10/2016 06:21 pm
For example: http://www.cnbc.com/2016/05/25/us-military-uses-8-inch-floppy-disks-to-coordinate-nuclear-force-operations.html

Yes, 8 inch floppies.

Maybe the eastern range still uses punch cards.

If the stuff is that old one would think they could run some virtual machines like KVM or emulators like MAME.    I wouldn't take much of a summer code hack (like the Google ones) to add the range machines to their emulation suites.
 
If they are still using Xerox Sigma's like when they went to the moon.... there is even an emulator out for that: https://www.andrews.edu/~calkins/sigma/sigma7.htm


Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: launchwatcher on 06/10/2016 06:46 pm
For example: http://www.cnbc.com/2016/05/25/us-military-uses-8-inch-floppy-disks-to-coordinate-nuclear-force-operations.html

Yes, 8 inch floppies.

Maybe the eastern range still uses punch cards.

If the stuff is that old one would think they could run some virtual machines like KVM or emulators like MAME.    I wouldn't take much of a summer code hack (like the Google ones) to add the range machines to their emulation suites.
That's the easy part - moving the brain in a jar to a different jar.

The hard part is connecting the software to the outside world.   Radars, cameras, weather sensors, who knows what else..   A non-trivial integration exercise.   Would be much easier to build a new range from scratch than keep an existing one running while you migrate it a piece at a time in between launches.

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Chris Bergin on 06/10/2016 07:32 pm
Was expecting to hear about a F9 rolling out by now. Inquiring as to what's going on. NROL-37 pulling rank?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Star One on 06/10/2016 09:15 pm
Was expecting to hear about a F9 rolling out by now. Inquiring as to what's going on. NROL-37 pulling rank?
Well it's a national security payload so surely it must take precedence over a commercial launch.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Chris Bergin on 06/10/2016 09:19 pm
Was expecting to hear about a F9 rolling out by now. Inquiring as to what's going on. NROL-37 pulling rank?
Well it's a national security payload so surely it must take precedence over a commercial launch.


Yeah, that certainly makes things very interesting, but I'd really like to know for sure. I've asked SpaceX....not much point asking ULA as I don't think they will be involved, it'll be more like NROL to the Range, Range to SpaceX.

I don't think I know anyone with the NROL. I think they all wear uniforms and have serious facial expressions ;D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rcoppola on 06/10/2016 09:25 pm
If they get bumped, then they should get a "Credit" from the range?

(was meant as a question, forgot the ?)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: DaveS on 06/10/2016 09:33 pm
If they get bumped, then they should get a "Credit" from the range.
They knew that the Delta IV had the Range for Thursday through Saturday. If I remember things correctly each user gets the launch day and then a 24hr and 48 scrub. So It's T0+48hrs. Then things have to negotiated (not a problem if the Range schedule is empty beyond the assigned 48hrs).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: baldusi on 06/10/2016 09:59 pm
I'm not sure that NROL would pull rank for this type of payload. Planetary? Sure. Life critical launches? Sure. But this thing is hardly time critical, and LC-37 is hardly at maximum utilization.
I would guess that if they scrub they might ask SpaceX nicely, and that's it.
In any case, bad weather means scubs for any LV.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ncb1397 on 06/10/2016 10:05 pm
I'm not sure that NROL would pull rank for this type of payload. Planetary? Sure. Life critical launches? Sure. But this thing is hardly time critical, and LC-37 is hardly at maximum utilization.
I would guess that if they scrub they might ask SpaceX nicely, and that's it.
In any case, bad weather means scubs for any LV.

U.S. military is engaged with ISIS now.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mvpel on 06/10/2016 10:29 pm
That's the easy part - moving the brain in a jar to a different jar.

The hard part is connecting the software to the outside world.   Radars, cameras, weather sensors, who knows what else..   A non-trivial integration exercise.   Would be much easier to build a new range from scratch than keep an existing one running while you migrate it a piece at a time in between launches.

Probably the reason they invented the emulators in the first place was to deal with keeping legacy VAX equipment running. One of my colleagues had to write a custom password strength enforcement driver for the VAX to comply with modern security standards - he's retired now.

But you're quite right - and you don't even need to build a new range from scratch, you can just drive it in and set it up:

Raytheon Mobile Range (http://www.raytheon.com/capabilities/products/mobilerange/)
Quote
Versatile, Mobile, High Fidelity Testing Capability
Mobile Range® is an integrated suite of communications, optics, and telemetry capabilities, which can be deployed anywhere in the world on land, at sea or in the air with minimal support staff or infrastructure. It enables in-country flight testing, demonstrations, and data collection in a variety of environments and conditions. The system has the ability to test anything that has an RF-transmitted data stream and can be set up and operational in as little as four hours.

(http://www.raytheon.com/rtnwcm/groups/public/documents/image/rms13_mobilerange_pic04.jpg)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Star One on 06/11/2016 07:12 am
I'm not sure that NROL would pull rank for this type of payload. Planetary? Sure. Life critical launches? Sure. But this thing is hardly time critical, and LC-37 is hardly at maximum utilization.
I would guess that if they scrub they might ask SpaceX nicely, and that's it.
In any case, bad weather means scubs for any LV.
How do you know it's not a critical replacement for prior satellite in the constellation that has failed. Some of the Orion's were launched some while ago now.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Mike_1179 on 06/11/2016 10:26 am
How does the range deal with support on weekends? If Falcon and Delta are both doing a static fire / launch on a Saturday and Sunday, maybe we're looking at range employee availability.

Isn't range staffing 40 hrs / week, Monday - Friday? They would cover work on weekends with shifting their time or overtime. Back when they would launch an Atlas and a Redstone all before breakfast, overtime pay might have been less of an issue.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Herb Schaltegger on 06/11/2016 11:58 am
How does the range deal with support on weekends? If Falcon and Delta are both doing a static fire / launch on a Saturday and Sunday, maybe we're looking at range employee availability.

Isn't range staffing 40 hrs / week, Monday - Friday? They would cover work on weekends with shifting their time or overtime. Back when they would launch an Atlas and a Redstone all before breakfast, overtime pay might have been less of an issue.

And probably a lot more (mostly military) people working, allowing multiple overlapping shifts to avoid risking overtired people trying to do too much with too few resources.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rockets4life97 on 06/11/2016 12:01 pm
I bet these kinds of delays remind Musk about how happy he'll be once Boca Chica is up and running.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: macpacheco on 06/11/2016 12:28 pm
So that's the reason for the move 48hrs earlier. SpaceX was trying to get its static fire done before the ULA launch. No joy.

Edit: Pure speculation. Just saying.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mdeep on 06/11/2016 02:00 pm
So what happened? Based on the unusual silence from all parties, various assumptions and folk at the Cape, it would appear ULA and SpaceX had their bookings lined up at the Cape, but after the scrub on Thursday, and potentially as late as on the day on Friday, the NROL folk said "hold on, I know there's very little chance of a problem, but I don't want our very expensive spy sat at ANY risk while still out there on top of the Delta IV-H" based on the tiny chance the F9 had a bad day during the Static Fire.

Potential caveat would be a bad scrub today for the D-IVH, resulting in the MST rolling back (which might provide the "protection" for the payload in the event of the above concern).

Replying to this from the update thread -

The MST was rolled forward sometime after Thursday's scrub and was still there this morning, so I suspect that doesn't factor into things.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Chris Bergin on 06/11/2016 02:05 pm
So what happened? Based on the unusual silence from all parties, various assumptions and folk at the Cape, it would appear ULA and SpaceX had their bookings lined up at the Cape, but after the scrub on Thursday, and potentially as late as on the day on Friday, the NROL folk said "hold on, I know there's very little chance of a problem, but I don't want our very expensive spy sat at ANY risk while still out there on top of the Delta IV-H" based on the tiny chance the F9 had a bad day during the Static Fire.

Potential caveat would be a bad scrub today for the D-IVH, resulting in the MST rolling back (which might provide the "protection" for the payload in the event of the above concern).

Replying to this from the update thread -

The MST was rolled forward sometime after Thursday's scrub and was still there this morning, so I suspect that doesn't factor into things.

Yeah, so I've noticed, so they have to launch or SpaceX continues to hold it would seem.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: baldusi on 06/11/2016 03:11 pm
I'm not sure that NROL would pull rank for this type of payload. Planetary? Sure. Life critical launches? Sure. But this thing is hardly time critical, and LC-37 is hardly at maximum utilization.
I would guess that if they scrub they might ask SpaceX nicely, and that's it.
In any case, bad weather means scubs for any LV.

U.S. military is engaged with ISIS now.
How do you know it's not a critical replacement for prior satellite in the constellation that has failed. Some of the Orion's were launched some while ago now.

Well, the reality has shown that SpaceX didn't do their ignition test. Apparently NROL did, in fact, made the call to Hawthone. I had understood that this was a straight to GSO launch and thus is not so critical as an EO satellite, or an SDS near North Korea. But they didn't took a chance.
This makes things not so straightforward, but sort of a conundrum. DIVH wouldn't demate to wait for the Falcon 9 launch. But Falcon 9 won't launch without a hot fire. Which NROL won't tolerate while their payload is mated to the DIVH. So it would seem that F9 will yield the range to DIVH not because of national priority to the launch per se, but for the structure of F9 and DIVH launch ops and NROL risk aversion.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Helodriver on 06/11/2016 03:44 pm
Shades of how the inaugural Falcon 1 flight was planned to fly from Vandenberg's SLC-3W but was stopped by concerns of the effect on a Titan IV stacked with an NRO payload on SLC-4E. The months of delays in the Titan campaign and the concerns eventually forced Spacex to make their first flight from Omelek.

It is NRO's culture to be risk averse in their business.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: joek on 06/11/2016 04:14 pm
We will probably never know the whole story, but ignoring the $/time factor for such a payload... For pre-flight operations (which presumably includes hot fire), SpaceX's launch license (http://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/LLS%2014-090%20Rev%202%20-%20License%20and%20Orders%20(FINAL)%2001_21_2016%20-%20signed%20copy.pdf) requires only $13M government property and $12M liability insurance.  I expect there might be serious nervousness on all sides--SpaceX, FAA, DoD, etc.--at the fallout if that bet was called.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/11/2016 04:30 pm

Mobile Range® is an integrated suite of communications, optics, and telemetry capabilities, which can be deployed anywhere in the world on land, at sea or in the air with minimal support staff or infrastructure. It enables in-country flight testing, demonstrations, and data collection in a variety of environments and conditions. The system has the ability to test anything that has an RF-transmitted data stream and can be set up and operational in as little as four hours.


The Eastern Range is just more than that.   It has been posted many times on this forum on the reasons for the 48 hours turnaround and outdated hardware is the least of the reasons
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CyndyC on 06/11/2016 04:52 pm
I expect there might be serious nervousness on all sides--SpaceX, FAA, DoD, etc.--at the fallout if that bet was called.

Seems if anyone would need to worry it wouldn't be NROL way over top of a 2 second hold down firing, it would be SpaceX & payloaders standing under a launch of the largest American rocket currently flying.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/11/2016 05:00 pm
Tory Bruno seems to imply that the Delta IV Heavy did not delay the Falcon 9 static fire?

https://twitter.com/torybruno/status/741673737905311745
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kevinof on 06/11/2016 05:05 pm
Tory Bruno seems to imply that the Delta IV Heavy did not delay the Falcon 9 static fire?

https://twitter.com/torybruno/status/741673737905311745
Not imply but state that the F9 static fire delayed the d4 heavy launch.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: joek on 06/11/2016 05:06 pm
Seems if anyone would need to worry it wouldn't be NROL way over top of a 2 second hold down firing, it would be SpaceX & payloaders standing under a launch of the largest American rocket currently flying.

And some of them might be thinking... We're only insured for a few $10M's and that thing over there is worth $100-1000M's... If anything goes wrong, where is the axe going to fall--not just financially but politically?  And should something bad happen, do pre-flight insurance requirements and premiums go through the roof or remain predictable?  Probably best to let it go and continue with alternatives for non-USG launches (e.g., Boca Chica).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: 5600k on 06/11/2016 05:07 pm
Tory Bruno seems to imply that the Delta IV Heavy did not delay the Falcon 9 static fire?

https://twitter.com/torybruno/status/741673737905311745
Not imply but state that the F9 static fire delayed the d4 heavy launch.

Right. Also the speculation is that the range would have told SpaceX to stand down.  Which is technically not ULA / or the Delta IV delaying the static fire.


Sent from my iPhone using Tapatalk
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/11/2016 05:38 pm
ow, wait just a dad-gummed minute.  Let me get this straight -- ULA couldn't do a 24-hr turnaround because SpaceX was doing a static fire the next day, and SpaceX couldn't do the static fire because the NROL bird was still on the pad?

So, if everyone had talked together properly on Thursday, ULA could have run a 24-hr turnaround and the F9 static fire would only have been delayed one day, not two?

Sorry, it seems to me that Bruno must have at least strongly suspected, if not known for certain, that SpaceX would not be allowed to perform the static fire before he flew his Delta.  Thus, if a 24-hr turnaround was possible, he ought to have known he could have gone for that.  Blaming SpaceX seems disingenuous at best...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/11/2016 06:07 pm
ow, wait just a dad-gummed minute.  Let me get this straight -- ULA couldn't do a 24-hr turnaround because SpaceX was doing a static fire the next day, and SpaceX couldn't do the static fire because the NROL bird was still on the pad?

Seems there's a doings a transpiring.

Hard to imagine a national security launch attempt being pushed for a test for a commercial launch.

Regardless, I think SpaceX and ULA would both be accommodating to NRO and other DOD clients.  It's good business and national security.

Best if there is some give and take by everyone.  One never knows when you need a favor.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Newton_V on 06/11/2016 07:03 pm
ow, wait just a dad-gummed minute.  Let me get this straight -- ULA couldn't do a 24-hr turnaround because SpaceX was doing a static fire the next day

Yes.  SpX had 6/10 reserved for quite a while, back when L-37 was supposed to go on the 5th, 6th, 8th, and then the 9th.  The 11th was the next available day.  OSL picks the launch date.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CJ on 06/11/2016 09:12 pm
Okay, so, Bruno says the DIV H launch was delayed because of the SpaceX static fire, one which didn't happen. But, we have a possible clue in the fact that the ASDS departed about 24 hours later than expected, which could indicate SpaceX knew they were definitely having a launch slip, and the fact they didn't say so could be related to being unable to if it involves a national security launch. Very puzzling.

Also, I can understand why they might not allow a static fire with a very expensive LV and bird on a somewhat nearby pad, but surely they could do the static fire now that the launch has occurred?

Something here does not add up. My current suspicion is a snafu regarding the various entities miscommunicating with each other.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/11/2016 10:41 pm
I con-quire, I think that SpaceX thought they could conduct the static fire and NRO or someone at some point said no you cannot.

To me this is just poor communication but without knowing more details we don't know who was not communicating. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: obi-wan on 06/11/2016 11:59 pm
Are all personnel cleared from LC40 due to launch operations at LC37? How about the other way around? I know in the 60's my dad was repeatedly told to shelter in place at one pad due to a nearby failure, but I wonder if policies have changed due to larger vehicles or just risk adversity. What's the exclusion zone for an F9 or DIVH?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: northenarc on 06/12/2016 12:57 am
Are all personnel cleared from LC40 due to launch operations at LC37? How about the other way around? I know in the 60's my dad was repeatedly told to shelter in place at one pad due to a nearby failure, but I wonder if policies have changed due to larger vehicles or just risk adversity. What's the exclusion zone for an F9 or DIVH?
Somewhat different risks perhaps because there were a lot of hypergolic rockets flying back then with risk of large drifting clouds of highly toxic propellants, the LOX rockets risk (regardless of fuel) is more explosive and flying debris.
  The way this seems to me is that SpaceX had the range booked for Friday and either ULA didn't ask them to release it or they said no, they were then told they couldn't proceed anyway with the Delta on the pad and everyone got bumped.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/12/2016 09:08 am
I suppose that there is a security aspect to it too. If the Delta-IVH had to be RSed, then the possibility of a very large lump of super-secret sensor or transmitter falling on SLC40 would have been extant. NRO understandably wouldn't want any non-cleared personnel assisting in the clean-up.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: obi-wan on 06/12/2016 06:56 pm
Are all personnel cleared from LC40 due to launch operations at LC37? How about the other way around? I know in the 60's my dad was repeatedly told to shelter in place at one pad due to a nearby failure, but I wonder if policies have changed due to larger vehicles or just risk adversity. What's the exclusion zone for an F9 or DIVH?
Somewhat different risks perhaps because there were a lot of hypergolic rockets flying back then with risk of large drifting clouds of highly toxic propellants, the LOX rockets risk (regardless of fuel) is more explosive and flying debris.
  The way this seems to me is that SpaceX had the range booked for Friday and either ULA didn't ask them to release it or they said no, they were then told they couldn't proceed anyway with the Delta on the pad and everyone got bumped.

Yeah, but the specific question is: did all personnel have to clear LC-40 for the DIVH launch yesterday? (If so, how long? From the start of fueling operations through the post-launch "all clear"?) Did all LC-37 personnel have to clear for today's F9 static fire? How about for Wednesday's launch? How large is the hazardous ops exclusion zone, and how does it vary between specific vehicles and/or operations? (You could see how hard it would be to maintain a schedule if someone keeps saying, "Sorry, but you can't prepare for your launch today because the group next door is doing something hazardous.")
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CyndyC on 06/12/2016 08:17 pm
Tory Bruno seems to imply that the Delta IV Heavy did not delay the Falcon 9 static fire?

https://twitter.com/torybruno/status/741673737905311745
Not imply but state that the F9 static fire delayed the d4 heavy launch.

Technically, yes. Considering the tug left with the ASDS Friday instead of Thursday, it appears SpaceX had no intention of rolling out and using their static fire reservation till they were certain the Delta IVH launch next door was completed. They might have offered ULA the Friday slot and ULA didn't take them up on their offer.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Coastal Ron on 06/12/2016 08:26 pm
Tory Bruno seems to imply that the Delta IV Heavy did not delay the Falcon 9 static fire?

https://twitter.com/torybruno/status/741673737905311745
Not imply but state that the F9 static fire delayed the d4 heavy launch.

Technically, yes. Considering the tug left with the ASDS Friday instead of Thursday, it appears SpaceX had no intention of rolling out and using their static fire reservation till they were certain the Delta IVH launch next door was completed. They might have offered ULA the Friday slot and ULA didn't take them up on their offer.

There is a lot of "stuff" that has to happen for a launch, so I wouldn't be surprised if ULA was operating under the assumption that the range was reserved for SpaceX to do a static fire, but then, for whatever reason, things changed between SpaceX, the range, and ULA.

And this may happen more in the future, as ULA continues to launch at their current rate, and SpaceX increases their launch rate.  I know there have been discussions on NSF talking about range modernization, and just in general launching a lot of rockets per month is going to take some getting used to.  Just think about how the airline traffic at a major airport can get congested, so this is probably the rocket version of that - which is why SpaceX is building their Texas launch facility, to try and reduce that congestion even as they increase their launch tempo.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: baldusi on 06/12/2016 09:49 pm
From what I understand, DIVH launch date was a week or so earlier. Thus, SpaceX reserved with some margin. But the NRO launch got delayed and they hit this catch-22 situation where DIVH couldn't launch because F9 wanted to do the test fire, but they couldn't because DIVH was at the pad with the very expensive NRO bird.
I like how the ISS have found an excellent way to solve this issue: pen everybody for the same date and let the one with the least delays launch first.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: OnWithTheShow on 06/12/2016 11:13 pm
So back in all the range discussions we went from 2 weeks to switch the range to another rocket and eventually got to 2 days. Then we were also told (by Jim I believe) that static fires also use the range assets. So wouldnt they then need the two days from the Delta IV first attempt to reconfigure for the F9 static fire?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/13/2016 01:30 am
So back in all the range discussions we went from 2 weeks to switch the range to another rocket and eventually got to 2 days. Then we were also told (by Jim I believe) that static fires also use the range assets. So wouldnt they then need the two days from the Delta IV first attempt to reconfigure for the F9 static fire?

Jim was talking about 2 days between launches for range tracking radar reconfiguration, etc. But a static fire does not require range radar tracking.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/13/2016 03:11 pm
And apparently the static fire was completed without anybody noticing.

Wasn't US Launch report watching it?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: SLC on 06/13/2016 03:27 pm
Just found this story from the June 11 page of FLORIDA SPACErePORT, on website http://spacereport.blogspot.co.uk:

 "Pipelines Needed to Expand Cape Canaveral Spaceport's Launch Capacity (Source: SPACErePORT)
Pipeline infrastructure for gaseous commodities (helium, etc.) at the Cape Canaveral Spaceport has been identified as a bottleneck for accommodating the higher launch rate that will be needed by a growing number of users. The current network of gas pipes supports only one user at a time and requires a ~24 hour turnaround between users. The resulting holdup has impacted not only launches but also pre-launch test operations."  ... and it continues with more detail.

Could this be relevant to the Falcon 9 - Delta IV Heavy schedule conflict?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: FutureSpaceTourist on 06/13/2016 03:36 pm
And apparently the static fire was completed without anybody noticing.

Wasn't US Launch report watching it?

Yes they were watching but clearly not at the right time of day ... I'm guessing SpaceX were a bit quick off the blocks for them! (static fires previously often being later in the day)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: manoweb on 06/13/2016 05:24 pm
So... when are they planning to launch this? I have seen a couple of conflicting date/times on the Internet.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Confusador on 06/13/2016 07:17 pm
Not to mention the Static Fire article on this very site (https://www.nasaspaceflight.com/2016/06/spacex-readies-falcon-9-reuse-testing/) still has the most current information

Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CyndyC on 06/13/2016 09:07 pm
Just found this story from the June 11 page of FLORIDA SPACErePORT, on website http://spacereport.blogspot.co.uk:

 "Pipelines Needed to Expand Cape Canaveral Spaceport's Launch Capacity (Source: SPACErePORT)
Pipeline infrastructure for gaseous commodities (helium, etc.) at the Cape Canaveral Spaceport has been identified as a bottleneck for accommodating the higher launch rate that will be needed by a growing number of users. The current network of gas pipes supports only one user at a time and requires a ~24 hour turnaround between users. The resulting holdup has impacted not only launches but also pre-launch test operations."  ... and it continues with more detail.

Could this be relevant to the Falcon 9 - Delta IV Heavy schedule conflict?

Sounds like it could be relevant, but someone like Jim would have to answer that one. He alluded to the subject just a couple of days ago:
It has been posted many times on this forum on the reasons for the 48 hours turnaround and outdated hardware is the least of the reasons.

Your news implies there might be a related infrastructure problem at the Cape. Someone on this morning's panel at the American Institute of Aeronautics and Astronautics (AIAA) 2016 annual forum (http://livestream.com/AIAAvideo/aviation2016), when asked if there were challenges greater than "The Disruption Challenge" they were discussing, said that airport runway drainage systems were built to codes that aren't sufficient to handle the increase in storms due to global warming. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cmcqueen on 06/14/2016 12:59 am
Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.

I find these local times difficult to work with—I'm in Australia and unfamiliar with Florida, USA time zones, especially factoring in daylight saving time changes. I know it's possible for me to figure it out with some looking up current time zones on the Internet, but it would make it a lot simpler for many of us readers if NSF articles could publish times in UTC as well.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AnalogMan on 06/14/2016 01:12 am
Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.

I find these local times difficult to work with—I'm in Australia and unfamiliar with Florida, USA time zones, especially factoring in daylight saving time changes. I know it's possible for me to figure it out with some looking up current time zones on the Internet, but it would make it a lot simpler for many of us readers if NSF articles could publish times in UTC as well.

The Eastern times quoted at this time of year translate to 14:29 to 15:13 UTC.

You could also take a look at this site's calendar which lists launch times in UTC:
https://forum.nasaspaceflight.com/index.php?action=calendar (https://forum.nasaspaceflight.com/index.php?action=calendar)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: manoweb on 06/14/2016 07:15 am
Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.

I find these local times difficult to work with—I'm in Australia and unfamiliar with Florida, USA time zones, especially factoring in daylight saving time changes. I know it's possible for me to figure it out with some looking up current time zones on the Internet, but it would make it a lot simpler for many of us readers if NSF articles could publish times in UTC as well.

And at least, the article should specify if the posted hours are AM or PM, as most Americans use a 12 hours format that is otherwise incomplete.

Good find about that calendar link, AnalogMan. Now also spaceflightnow lists the launch happening on June 15th, so I believe there is a consensus on this date/time. I find it strange that the SpaceX webpage has not been updated yet to mention "Eutelsat 117W B & ABS 2A", it seems like they have abandoned it... is there any indication if they are going to stream this launch live?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/14/2016 07:52 am
The webcast links (hosted and technical)  will show up on the SpaceX YouTube channel first. Their  website stream is just a mirror of their YouTube hosted stream.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: faramund on 06/14/2016 08:42 am
Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.

I find these local times difficult to work with—I'm in Australia and unfamiliar with Florida, USA time zones, especially factoring in daylight saving time changes. I know it's possible for me to figure it out with some looking up current time zones on the Internet, but it would make it a lot simpler for many of us readers if NSF articles could publish times in UTC as well.

The Eastern times quoted at this time of year translate to 14:29 to 15:13 UTC.

You could also take a look at this site's calendar which lists launch times in UTC:
https://forum.nasaspaceflight.com/index.php?action=calendar (https://forum.nasaspaceflight.com/index.php?action=calendar)
I'm also in Australia, but I just look at
https://spacexstats.com/
(just scroll down a bit, and there's a countdown to the next launch)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rpapo on 06/14/2016 10:13 am
FWIW, the Wikipedia page on Falcon 9 launch history and future launches (https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_Heavy_launches#Future_launches) shows the times in UTC always.  I forgot that, and so thought the launch was going to be precisely when I would normally leave work tomorrow...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: linxiaoyi on 06/14/2016 12:33 pm
So do we know the real mass of this pair of satellites? I think that 4.2 ton we knew previously is ABS-3A Eutelsat 115 West B mission's.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/14/2016 01:56 pm
So do we know the real mass of this pair of satellites? I think that 4.2 ton we knew previously is ABS-3A Eutelsat 115 West B mission's.

I believe this pair of sats is identical.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: pospa on 06/14/2016 02:22 pm
... also no press kit, neither mission patch just  T -1 day is a bit strange, isn't it?  ???
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 06/14/2016 02:47 pm
So do we know the real mass of this pair of satellites? I think that 4.2 ton we knew previously is ABS-3A Eutelsat 115 West B mission's.

I believe this pair of sats is identical.

They are similar but not identical.  Eutelsat 117W B is carrying a hosted payload for the FAA.  There are probably other differences.

SpaceNews: After Delay, Satmex Finalizes Deal to Host Raytheon WAAS Payload (http://spacenews.com/39490after-delay-satmex-finalizes-deal-to-host-raytheon-waas-payload/)
Quote
a Raytheon-produced payload to maintain the Wide-Area Augmentation System (WAAS) capability over the Americas will ride aboard Mexican satellite fleet operator Satmex’s Satmex 9 satellite, scheduled for launch in late 2015.
Eutelsat 117W B was originally called Satmex 9.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 06/14/2016 02:49 pm
Tweet from James Dean (https://twitter.com/flatoday_jdean/status/742726650404720640):
Quote
Eutelsat 117 West B sits on top and will be deployed first; ABS-2A below (opposite from pair launched last year).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: starhawk92 on 06/14/2016 06:09 pm
Quote
The launch window for Wednesday’s attempt opens at 10:29 Eastern and is available through to 11:13.

I find these local times difficult to work with—I'm in Australia and unfamiliar with Florida, USA time zones, especially factoring in daylight saving time changes. I know it's possible for me to figure it out with some looking up current time zones on the Internet, but it would make it a lot simpler for many of us readers if NSF articles could publish times in UTC as well.

Check the appropriate footnotes:
https://forum.nasaspaceflight.com/index.php?topic=40231.0
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/14/2016 10:21 pm
... also no press kit, neither mission patch just  T -1 day is a bit strange, isn't it?  ???

They're out now. Links on the "updates" page.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CarlG on 06/14/2016 11:14 pm
Do we know what longitude the deployment will take place?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hans_ober on 06/15/2016 01:49 am
Do we know what longitude the deployment will take place?

A little east of 0?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 02:08 am
Do we know what longitude the deployment will take place?

Judging from past SpaceX GTO launches, somewhere between Central Africa and Madagascar?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: deruch on 06/15/2016 02:37 am
Do we know what longitude the deployment will take place?
You could rewatch the first Eutelsat/ABS launch coverage.  I would assume that this launch will be largely a repeat of that one.  If nothing else, it should give a fair rough estimate.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Scylla on 06/15/2016 03:15 am
What are the protrusions around the bottom of the fairing?

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ethan829 on 06/15/2016 03:18 am
What are the protrusions around the bottom of the fairing?


Covers for pressure equalization openings. They're covered before launch to prevent any kind of contaminants from getting in and are designed to fall off during launch, hence the forward-facing scoop shape.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/15/2016 05:51 am
Estimated location of Of Course I Still Love You based on the cords of the last known location of the SpaceX boats. https://goo.gl/maps/SSwoM5gyLaD2
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/15/2016 12:01 pm
Fascinating! A Bowser collar for the fairing...

I bet they're some kind of sensor (radar antenna? Diff GPS? ) related to fairing recovery.

Would think that may have some interesting effects transsonic as well.

Sigh.

http://forum.nasaspaceflight.com/index.php?topic=40088.msg1549392#msg1549392
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/15/2016 12:14 pm
Well, at least everyone gets to take a shot in the SpaceX prelaunch drinking game.

I'll answer the next question preemptively: the stiffening ring around the second stage engine is meant to come off.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Herb Schaltegger on 06/15/2016 12:22 pm
Well, at least everyone gets to take a shot in the SpaceX prelaunch drinking game.

I'll answer the next question preemptively: the stiffening ring around the second stage engine is meant to come off.

Too early for a shot but if it's any consolation, you almost made me snort coffee out my nose.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CyndyC on 06/15/2016 12:50 pm
Standing in line next to Saturn 5 for LC-39 Gantry buses. There will be 10 busloads of 45 people each

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: bsegal on 06/15/2016 01:20 pm
Webcast countdown clocks seem to be synchronized to launch time, not webcast start time, unless they've moved T-0 back.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hans_ober on 06/15/2016 01:26 pm
Webcast countdown clocks seem to be synchronized to launch time, not webcast start time, unless they've moved T-0 back.

Always the case. They just start the webcast early.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/15/2016 01:53 pm
Take a shot!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: vanoord on 06/15/2016 02:01 pm
Webcast holding page and music starting.

Just in case: http://www.spacex.com/webcast
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gongora on 06/15/2016 02:02 pm
Eutelsat posted this on Twitter (https://twitter.com/Eutelsat_SA/status/743065986300018688), gives the mass for one of the spacecraft (1963kg):

(https://pbs.twimg.com/media/Ck_mkvWW0AEJaJO.jpg)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/15/2016 02:13 pm
My friend works at a NOC.  When you can't decide which webcast to watch. 

Hosted webcast on right and technical webcast on left.


Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mvpel on 06/15/2016 02:20 pm
I've never noticed the hold-down water deluge before - is that new?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: neoforce on 06/15/2016 02:27 pm
not able to watch live at the moment...  this is from the update thread:

T-8 minutes. Between 8 minutes and 9 minutes Mission Elapsed Time, we should expect the first stage to land on the OCISLY barge. Should the barging be successful, the LC-39A hangar would then attempt to hold five first stages.

Was that stated on the webcast?  Wasn't one of the first stages moved out?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mvpel on 06/15/2016 02:32 pm
Looks like the diversion of the second stage startup plume happened again, did I see that correctly?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sghill on 06/15/2016 02:39 pm
That did not look like a happy ending for the flaming first stage right before the video froze up.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: jimbowman on 06/15/2016 02:40 pm
Looked like one of the landing legs was completely on fire.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/15/2016 02:40 pm
In one of the frames, you can see the stage standing upright and on fire.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lars-J on 06/15/2016 02:41 pm
In one of the frames, you can see the stage standing upright and on fire.
Yes, it was upright at least for that frame.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/15/2016 02:42 pm
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Pete on 06/15/2016 02:46 pm
Landed, or not landed?

Well, we have one picture of it on the deck, four landing legs all within the perimeter.
And a LOT of flame, especially on the left of the image.

Good grief this is tense!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kevinof on 06/15/2016 02:48 pm
Landed, or not landed?

Well, we have one picture of it on the deck, four landing legs all within the perimeter.
And a LOT of flame, especially on the left of the image.

Good grief this is tense!

SpaceX is the new entertainment company.

Wonder did it go boom after the landing and took out the comms?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/15/2016 02:48 pm
not able to watch live at the moment...  this is from the update thread:

T-8 minutes. Between 8 minutes and 9 minutes Mission Elapsed Time, we should expect the first stage to land on the OCISLY barge. Should the barging be successful, the LC-39A hangar would then attempt to hold five first stages.

Was that stated on the webcast?  Wasn't one of the first stages moved out?
You are correct, that post was in error.  There are only two stages in the hangar right now, and one of those is on its way out, perhaps before OCISLY gets back.

They did not say anything about this on the webcast.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ulm_atms on 06/15/2016 02:48 pm
They had a fuel leak somewhere...that's for sure....

Man that's was LOTS of flame compared to every other landing.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wxmeddler on 06/15/2016 02:49 pm
Schrodinger's Rocket.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 02:50 pm

Wonder did it go boom after the landing and took out the comms?

Or SpaceX cut the feed.

I am entertained!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/15/2016 02:50 pm
Landed, or not landed?

Well, we have one picture of it on the deck, four landing legs all within the perimeter.
And a LOT of flame, especially on the left of the image.

Good grief this is tense!
I saw that too. Guessing RUD though. No word about it on the radio, webcast, or SpaceX twitter which in the past has not been a good sign. I thought at first that the fire was coming from the Merlin engines as we sometimes see after a landing. However, I would think that if it landed they would have told us by now. Ships in the atlantic should have a visual on the landing even if they lost contact with the Falcon 9.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: toruonu on 06/15/2016 02:51 pm
Schrodinger's Rocket.

Just was about to make the exact same comment, ideal example of this thought experiment ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: inventodoc on 06/15/2016 02:51 pm
spacex MO is to clam up when something goes wrong. Probably need very senior approval to disclose negative news.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kaputnik on 06/15/2016 02:52 pm
Haven't felt like this since Jason 3...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/15/2016 02:52 pm
Could the landing have been so high-g that the prop tanks/lines could have ruptured and the residual propellent ignited?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/15/2016 02:53 pm
I think there was simply a fire in the engine compartment that spread to the tanks just after landing.  That's consistent with what we've seen, anyway.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 02:54 pm
To distract from the "did it land" tension, watching stage separation from within the interstage was absolutely SPECTACULAR! If you missed it, rewind the livestream!

We watched the second stage separate, fire up its engine, and then quickly accelerate away. I also didn't know the interstage had that pyramidal strut structure, I'm guessing to support the M1D Vac nozzle extension.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/15/2016 02:54 pm
My guess is that the leg fire compromised the structure and it buckled and fell over.  Would be glad to be wrong though!

And folks, no SpaceX conspiracy theories please.  The folks there have the same inconclusive evidence we have, plus some additional footage, probably from the support ships and far away... thus also inconclusive.  It certainly didn't sound promising, but I doubt anyone was *certain* about what they are seeing as of the end of the webcast.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Retired Downrange on 06/15/2016 02:54 pm
Schrodinger's rocket......
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 02:55 pm
Second stage restart!

On a landing failure it makes a lot of PR sense to wait until after payload deployment to announce the landing RUD. That way the headline reads "SpaceX successfully deploys multiple satellites; misses first stage landing" instead of "SpaceX rocket explodes catastrophically on boat; payload status still uncertain".

I don't think it's a "conspiracy theory" to say that they wait to confirm stuff.

Guessing RUD though. No word about it on the radio, webcast, or SpaceX twitter which in the past has not been a good sign. I thought at first that the fire was coming from the Merlin engines as we sometimes see after a landing. However, I would think that if it landed they would have told us by now. Ships in the atlantic should have a visual on the landing even if they lost contact with the Falcon 9.
What's the safe holdoff distance from the ASDS?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/15/2016 02:56 pm
To distract from the "did it land" tension, watching stage separation from within the interstage was absolutely SPECTACULAR! If you missed it, rewind the livestream!

We watched the second stage separate, fire up its engine, and then quickly accelerate away. I also didn't know the interstage had that pyramidal strut structure, I'm guessing to support the M1D Vac nozzle extension.

The pyramid supports the center pusher for stage separation.

Also, we learned from one of the hosts that the grid fins are, in fact, made from aluminum as we suspected.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: matthewkantar on 06/15/2016 02:57 pm
To distract from the "did it land" tension, watching stage separation from within the interstage was absolutely SPECTACULAR! If you missed it, rewind the livestream!

We watched the second stage separate, fire up its engine, and then quickly accelerate away. I also didn't know the interstage had that pyramidal strut structure, I'm guessing to support the M1D Vac nozzle extension.

I think it is the center pusher.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Pete on 06/15/2016 02:57 pm
Landing go boom.   :(
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/15/2016 02:57 pm
First stage update

"It appears as though we lost the vehicle"
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/15/2016 02:58 pm
I just rewatched the landing. IMO the following image shows a Falcon 9 standing up tall among the smoke. My prediction is that it landed fine, but like last time most of the aluminum honeycomb in the legs was used. Unlike last time I am guessing that it tipped over and exploded.

Edit: That looks like two merlin engines towards the bottom left section of the image. Falcon 9 body appears to be among the smoke.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/15/2016 02:59 pm
Did it sound like around T- 8:46 on the technical broadcast like a vehicle started and then drove away?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/15/2016 03:00 pm
The switch between a clear deck and an inferno was so sudden that I wonder if the vehicle ran dry before touch-down and hit at a steep angle (as there was no thrust to correct attitude and the grid fins don't work too well at subsonic speeds).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 03:00 pm
Too much fire, failed a leg?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/15/2016 03:03 pm
The switch between a clear deck and an inferno was so sudden that I wonder if the vehicle ran dry before touch-down and hit at a steep angle (as there was no thrust to correct attitude and the grid fins don't work too well at subsonic speeds).

I don't think so, it looked like it was landed and upright, but with the entire lefty side of the vehicle (as seen from the camera position) engulfed in flames.

Whatever happened after we lost the feed, the stage was momentarily sitting upright on its legs, I'm about as sure of that as I can be...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 03:03 pm
Thanks for the clarification, guys. Center pusher it is. I had never seen it before.

Bummer for the first stage.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: whitelancer64 on 06/15/2016 03:03 pm
The switch between a clear deck and an inferno was so sudden that I wonder if the vehicle ran dry before touch-down and hit at a steep angle (as there was no thrust to correct attitude and the grid fins don't work too well at subsonic speeds).

Grid fins work very well at supersonic and subsonic speeds. Where they don't work well is in the trans-sonic, because the shock waves block the airflow between the grids.

However just at landing aerodynamic controls wouldn't have much authority, most control comes from gimballing the rocket engine.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 03:04 pm
We definitely had multiple frames with the stage body vertical and at least two landing legs visible, so it must have either been a tipover or an engine/tank breach. The former is possible if the crush core was mostly used and excessive fire weakened it.

JASON-3 was lost due to icing on the lockout collet; looks like this one was lost due to fire.

A song of ice and fire....
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gospacex on 06/15/2016 03:04 pm
"Altitude" is pegged at exactly 100. I take it it's not a real value?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/15/2016 03:04 pm
Stage 2 telemetry shows altitude at 100km right now...
T+35 minutes
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: John Alan on 06/15/2016 03:05 pm
Too much fire, failed a leg?

Wondering if an RP-1 leak fed a fire that burned till a leg got weak then it fell over...
This over a couple mins time...
Wild azz guess based on it seemed to be upright and at a standstill for a second at least...
 ???

On edit...
We know from multiple sources now it was a total loss in the end...  :(

Later edit...
And we now know it landed hard from EM tweet... see below...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/15/2016 03:06 pm
FWIW, it should now start to be possible to start calculating the statistical likelihood of a Stage-1 recovery from a GTO launch based against target orbit and dV usage by the stage. We're still a very long way from cast iron numbers but the general shape should now just begin to be apparent.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: SoulWager on 06/15/2016 03:07 pm
"Altitude" is pegged at exactly 100. I take it it's not a real value?

It rolled back over to 100 after it hit 999km.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: DragonRider on 06/15/2016 03:09 pm
It looked like it landed and was upright for some period of time, or at least it seemed that way. I hope they release footage later from the ship as it's a peculiar one.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 03:09 pm
FWIW, it should now start to be possible to start calculating the statistical likelihood of a Stage-1 recovery from a GTO launch based against target orbit and dV usage by the stage. We're still a very long way from cast iron numbers but the general shape should now just begin to be apparent.
Doing statistics based on the first few instances of a series is not the best idea...

https://xkcd.com/605/
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Saabstory88 on 06/15/2016 03:09 pm
Per Musk's comment. Was it not low thrust in an engine which caused SES-9 to fail to land?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 03:10 pm
Musk tweeted that RUD was due to low thrust on 1 of 3 engines.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/15/2016 03:10 pm
@elonmusk
Looks like thrust was low on 1 of 3 landing engines. High g landings v sensitive to all engines operating at max.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/15/2016 03:10 pm
Either a fault on the engine or low propellent remaining so one engine somehow got short-changed. The result was likely a far more energetic deck contact than the vehicle's hull could withstand leading to a structural failure and boom.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: DragonRider on 06/15/2016 03:11 pm
Oh well, the hangar was getting pretty full anyway.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 03:12 pm
Is there any way for RP1 to leak from the tank w/o there being a pressure vessel burst?

Like a flange developing a leak and spraying the fuel out?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: brlavalamp on 06/15/2016 03:14 pm
@elonmusk
Looks like thrust was low on 1 of 3 landing engines. High g landings v sensitive to all engines operating at max.

I still think that it landed fine on all four legs, but just happen to be on fire.  Low thrust could also indicate some kind of engine damage that would also cause fuel to leak, with the resulting fire and RUD.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 03:16 pm
I hate it when they clam up like that, it'll be weeks before we hear anything...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/15/2016 03:16 pm
Quote
Elon Musk ‏@elonmusk 49s49 seconds ago

Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year.

https://twitter.com/elonmusk/status/743099301174247424 (https://twitter.com/elonmusk/status/743099301174247424)

Curious. I can't see how they could wring more out of the engines. Maybe improved shock absorbers in the landing struts?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: DragonRider on 06/15/2016 03:17 pm
If this was just a fire that got out of control I wonder if a larger extinguisher system could have saved things here.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kaputnik on 06/15/2016 03:17 pm
Quote
Elon Musk Twitter:
Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year.

I wonder what these upgrades will be?
Also, this confirms that 3-burn landings are here to stay.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 03:17 pm
I hate it when they clam up like that, it'll be weeks before we hear anything...

They already said it failed and why.  But we'll likely not get to see any video of what happened.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 03:18 pm
With Elon's explanation that one of the three landing engines had low thrust, we can guess what happened. Stage orientation is prioritized over stage speed (for obvious reasons) so the engines would be gimballing hard to adjust for the low thrust, further reducing axial thrust and total remaining dV. There was clearly a touchdown, but it probably happened at too high a vertical velocity for the legs to remain intact, and so either the shock caused an internal rupture and explosion, or it tipped over.

Can't quite determine whether there would have been significant remaining propellant. If the deceleration wasn't high enough, the engines could have still been firing at touchdown since it would have come down a few moments early, even with no reserve propellant.

They will be poring over the data from the ascent burn and entry burn to determine whether there was any indication of a problem during that stage. Hopefully they will be able to determine why there was a problem...was it too much heating during re-entry, or was it an pre-existing engine issue? If there is no data during the entry burn to identify, then it would seem likely that the damage occurred during the entry burn itself.

If there is an indication in the entry burn of a thrust shortfall then I'm sure they will reprogram to begin the landing burn earlier to accommodate. Elon's latest tweet (https://twitter.com/elonmusk/status/743099301174247424) mentions that the upgrades this fall would enable the other two engines to better compensate for a thrust shortfall...presumably a 104% thrust situation.

Hopefully the octaweb and some of the engines are recoverable!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/15/2016 03:18 pm
Contrast enhanced peek a boo
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 03:19 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/15/2016 03:20 pm
I hate it when they clam up like that, it'll be weeks before we hear anything...

Remember, Elon leans forward with Twitter.   ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Brovane on 06/15/2016 03:21 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.

How does a engine running low on propellant call into question the reuse-ability of the engine? 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/15/2016 03:21 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.

It may have more to do with helium bubbles being ingested at low propellant levels.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/15/2016 03:22 pm
@elonmusk
Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AncientU on 06/15/2016 03:23 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.

How does a engine running low on propellant call into question the reuse-ability of the engine?

More on defining the recovery parameter space.
Hardware/software changes are apparently being implemented, but there is a point of diminishing returns... the operating envelope boundary.

Several flights (seven I believe) are between 5,000kg and 5,500kg over next thirteen launches.  This will go far to establishing the boundaries.

http://forum.nasaspaceflight.com/index.php?topic=40231.0

Edit: Added link and checked numbers.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rpapo on 06/15/2016 03:24 pm
Looks like the diversion of the second stage startup plume happened again, did I see that correctly?
Looks to me like the new pusher leaves the second stage turning slightly, and the first thing that has to happen is to get back in the right orientation.  Saw this on the Thaicom launch too.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Nomadd on 06/15/2016 03:24 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.

How does a engine running low on propellant call into question the reuse-ability of the engine? 
Try reading the quote you posted again.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JERSON on 06/15/2016 03:30 pm
JJ Abrams liked the mission end.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 03:32 pm
On these "experimental" landings, I'm sure they are pushing the envelope on everything they possibly can, in every possible way, so as to gain the maximum amount of data and know exactly what their vehicle is capable of later on down the road.

Elon says the landing video will be posted later today. (https://twitter.com/elonmusk/status/743102502225076227) Which, given the typical inflation of timelines he claims, means September.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 03:32 pm
Quote
@elonmusk link (https://twitter.com/elonmusk/status/743102502225076227)
Landing video will be posted when we gain access to cameras on the droneship later today. Maybe hardest impact to date. Droneship still ok.

Yay :D. I love how Musk is esentially still a big nerd.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Tuts36 on 06/15/2016 03:32 pm
I hate it when they clam up like that, it'll be weeks before we hear anything...

Am I the only one who noticed the sarcasm in there?  ;)


My question - how would a low thrust on 1 engine = the stage being on fire at landing?  Is it possible there was more than one problem this time?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Toast on 06/15/2016 03:35 pm
FWIW, it should now start to be possible to start calculating the statistical likelihood of a Stage-1 recovery from a GTO launch based against target orbit and dV usage by the stage. We're still a very long way from cast iron numbers but the general shape should now just begin to be apparent.
Doing statistics based on the first few instances of a series is not the best idea...

https://xkcd.com/605/

Yeah, I'm getting ready to update my launch reliability statistics, and I've debated including SpaceX landing statistics but the confidence interval is really still too large.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mme on 06/15/2016 03:37 pm
Unless the low thrust was due to propellant depletion, this does call into question the reuse-ability of the engines.
Sure.  If the low thrust was do to damage to the engine via a mechanism that can't be understood and fixed.  Which I doubt.  But I'm an optimist.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 03:43 pm
I hate it when they clam up like that, it'll be weeks before we hear anything...

Remember, Elon leans forward with Twitter.   ;)
That he does...

And yeah, I was being sarcastic.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: pb2000 on 06/15/2016 03:50 pm
I wonder what'll be left on deck? Jason 3 appeared to have a good chunk of the ocaweb intact, and it wasn't a high velocity mission, so it had plenty of fuel to go boom.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: dmc6960 on 06/15/2016 03:51 pm
Elon says the landing video will be posted later today. (https://twitter.com/elonmusk/status/743102502225076227) Which, given the typical inflation of timelines he claims, means September.

On the JSON-3 launch, Elon posted the landing video 8 1/2 hours after launch.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AncientU on 06/15/2016 03:52 pm
Quote
@elonmusk link (https://twitter.com/elonmusk/status/743102502225076227)
Landing video will be posted when we gain access to cameras on the droneship later today. Maybe hardest impact to date. Droneship still ok.

Yay :D. I love how Musk is esentially still a big nerd.

Not sure how hardest to date refers to landing parameters, since there didn't seem to be a hole in the deck of OCISLY.  Maybe he refers to parameters for the final burn of something...  impact seemed mild?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: abaddon on 06/15/2016 03:52 pm
@elonmusk
Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year.
Worth noting this indicates they are already in progress addressing this issue, probably starting sometime after SES-9 hard landing.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mme on 06/15/2016 04:11 pm
Well, at least everyone gets to take a shot in the SpaceX prelaunch drinking game.

I'll answer the next question preemptively: the stiffening ring around the second stage engine is meant to come off.
One of the unsung advantageous of the latest upgrades is that the launches no longer "look slow."
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/15/2016 04:12 pm
I get the feeling that when Elon says this was the hardest landing yet, I think he means of those that actually landed on the legs.  I'd have to think that SES-9 hit OCISLY harder, since we did see that this stage was on its legs and upright, at least momentarily.  From the size and location of the hole SES-9's stage left in OCISLY, that stage obviously never sat on its legs on the deck.  I can't imagine that this one hit the ship harder than SES-9's stage did.

Therefore, apparently, Musk doesn't consider SES-9 a landing in any way, if this one is the hardest "landing" thus far...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/15/2016 04:15 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lars-J on 06/15/2016 04:16 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?

Yes.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Toast on 06/15/2016 04:17 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?

Yes, during one of the first launches of the Falcon 9 they had an engine out and the primary mission completed successfully (due to NASA constraints, the secondary payload was lost, but likely could have successfully completed mission as well). With the upgrades of F9 1.1 and 1.2, the rocket can tolerate even more losses in performance of the first stage, but at the cost of being able to recover the rocket.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: macpacheco on 06/15/2016 04:18 pm
@elonmusk
Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year.

This is what I love about Spacex.  The rud occurred less than 5 minutes before they identified and started to rectify the problem.  This is why they are the ones to beat.  CONGRATS, SPACEX!!

Most likely SpaceX was already planning to enhance F9 landing envelope prior to this landing RUD. This event just gave SpaceX to divulge some of their plans.
More than one SpaceXer said that if the public knew everything SpaceX is working one, they would think they're nuts. I think that's the important point.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Robotbeat on 06/15/2016 04:19 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?
Yes and maybe. They've had an engine-out before and were able to compensate enough for primary mission full success, although they didn't have enough for a small secondary payload. But the newer version of Falcon 9 has much better performance.

Additionally, they should have an upgraded setting for high thrust on the Merlin 1Ds out by the end of this year.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 04:22 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?

Yes it can. This actually already happened. During CRS-1 one of the outboard Merlin engines failed, but the Falcon 9 still got into orbit by burning the remaining 8 engines longer. Here's a slo-mo video (failure occurs around the 0:37 mark):

https://www.youtube.com/watch?v=pTeiInqRIzg
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/15/2016 04:29 pm

This is what I love about Spacex.  The rud occurred less than 5 minutes before they identified and started to rectify the problem.  This is why they are the ones to beat.  CONGRATS, SPACEX!!

That is not unique to Spacex.  Also, see CRS-7.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/15/2016 04:30 pm
Congrats SpaceX on successfully delivering 2 more payloads. 

Mission Success!

Next one is a RTLS, that's worth in the 4 week wait!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mr. mark on 06/15/2016 04:35 pm
I was wondering about camera angles of the second stage engine bell in relation to the Earth view. The earth angle seems confusing to me as it changes from view to view radically. Can someone please explain the camera angle in relationship to the Earth.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: watermod on 06/15/2016 04:37 pm
Wasn't the barge due for an inspection soon?   If so will damage be fixed before or after the inspection?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/15/2016 04:38 pm
The cameras are 180 deg apart, on the opposite sides of the engine nozzle. They are obviously meant to provide near-complete coverage on the nozzle extension.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AncientU on 06/15/2016 04:46 pm
Just out of curiosity, if there was a performance issue with a Merlin engine after liftoff would the Falcon 9 be able to compensate with the other engines?
Yes and maybe. They've had an engine-out before and were able to compensate enough for primary mission full success, although they didn't have enough for a small secondary payload. But the newer version of Falcon 9 has much better performance.

Additionally, they should have an upgraded setting for high thrust on the Merlin 1Ds out by the end of this year.

And that high(er) thrust feature could be part of the solution to today's single engine under-performance... other two could be ramped up to compensate.  If this is the 1.9Mlbf vs 1.7Mlbf change, it would be an 11-12% bump.

I suspect the same bump will improve their ability to accommodate engine out on ascent, too.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/15/2016 04:47 pm
Congrats SpaceX on successfully delivering 2 more payloads. 

Mission Success!

Next one is a RTLS, that's worth in the 4 week wait!
RTLS will be exciting. However, the landing will take place at night unfortunately. Can't wait for the first RTLS during the day time. Imagine all the amazing camera views there will be of it landing.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/15/2016 04:50 pm
RTLS will be exciting. However, the landing will take place at night unfortunately. Can't wait for the first RTLS during the day time. Imagine all the amazing camera views there will be of it landing.

You actually made me salivate.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 05:25 pm
I'm thinking about the book of "combat stories" that's growing with every mission...

That time when we had to stabilize a rocking stage that was "this close" to the edge
That time the leg didn't lock and we watched helplessly as it sloooowwwwwly tippped over
That time it landed, caught fire, and fell over
That time it nearly nailed through the barge

I wonder if the crew is playing "landing Bingo" but for real, with a can of spray paint....
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: clongton on 06/15/2016 05:25 pm
I wonder what these upgrades will be?
Also, this confirms that 3-burn landings are here to stay.

I wonder if the F9 could do a 5-engine final descent to the barge with throttling down all 5 engines for redundancy? 5 engines at partial thrust use approximately the same propellant load, then kill 2 outer engines just before slam-down? Perhaps the upgrades will allow deeper throttle (maybe)? that would be good.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: clongton on 06/15/2016 05:33 pm
I'm thinking about the book of "combat stories" that's growing with every mission...

That time when we had to stabilize a rocking stage that was "this close" to the edge
That time the leg didn't lock and we watched helplessly as it sloooowwwwwly tippped over
That time it landed, caught fire, and fell over
That time it nearly nailed through the barge

I wonder if the crew is playing "landing Bingo" but for real, with a can of spray paint....


Kinda like painting little Falcon 9 images on the side of the barge hulls like WWII fighter planes showing how many kills it got (ducking now lol) :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: FlokiViking on 06/15/2016 05:33 pm
I'm thinking about the book of "combat stories" that's growing with every mission...

That time when we had to stabilize a rocking stage that was "this close" to the edge
That time the leg didn't lock and we watched helplessly as it sloooowwwwwly tippped over
That time it landed, caught fire, and fell over
That time it nearly nailed through the barge


I'm guessing that this one is:
"That time it sat down on its engine nozzles"

Looking forward to video...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 05:36 pm
I wonder what these upgrades will be?
Also, this confirms that 3-burn landings are here to stay.

I wonder if the F9 could do a 5-engine final descent to the barge with throttling down all 5 engines for redundancy? 5 engines at partial thrust use approximately the same propellant load, then kill 2 outer engines just before slam-down? Perhaps the upgrades will allow deeper throttle (maybe)? that would be good.
They'd need to re-plumb the TEA/TEB restart igniters.

All nine engines are started at launch using TEA/TEB plumbing at the launch pad; only three are restartable in flight.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 05:39 pm

That time it landed, caught fire, and fell over


then sank into the swamp!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsnellenberger on 06/15/2016 05:47 pm

That time it landed, caught fire, and fell over


then sank into the swamp!

Then we built another one...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: feynmanrules on 06/15/2016 05:50 pm
perhaps this has been covered elsewhere and I missed it, if so would appreciate a link...  two questions:

1) I've been wondering why did spx not do a boost back burn, when they've done them on previous successful GTO mission landings? [corrected:my mistake, they weren't doing boost back for previous gto missions]

2) also.... i thought this was a lower mass mission, so they would have even more fuel left than they did previously like with thaicom?   for eutelsat they didn't do a boost back, so they should've had even more fuel to slow down, no?   [corrected: nm :)]

[as to whether lower mass should have given more fuel, two answers received]

Quote
Second, yeah, this mission did launch a little less mass to GTO than a few earlier missions, so yeah, it should have had a little better fuel margin.  So, unless there was some fuel issue during initial boost that no one has mentioned, I'd have to say that the one engine not ramping up to full thrust was more likely to have been an issue with damage to the engine from entry, as opposed to any kind of fuel depletion.

[SSTO may be culprit?]

Quote
I don't recall whether Thaicom-8 was a super-synchronous GTO injection, but this one was. Super-synchronous takes the apogee past GTO distance, far enough that the period of the elliptic orbit is 24 hours. Takes more dV than a simple GTO.





Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/15/2016 05:52 pm

1) i've been wondering why did spx not do a boost back burn, when they've done them on previous successful GTO mission landings?


I don't think any of the GTO missions had boost-back burns.  the last one certainly did not.

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/15/2016 05:54 pm
Wasn't the barge due for an inspection soon?   If so will damage be fixed before or after the inspection?

Since stage appeared to touch down on its legs, we can hope it was "only" a tipover/explosion after touchdown, in which case barge repairs should be minor, at least as compared to the SES-9 hole-punch.

The drydock inspection reportedly being requested by the Coast Guard may take some time to schedule and perform, since it will require sending OCISLY off to a drydock wide enough to accommodate her wings. That could be months down the road.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 05:59 pm

1) i've been wondering why did spx not do a boost back burn, when they've done them on previous successful GTO mission landings?
SpaceX did not do a boostback burn on previous GTO missions. Boostback is only for RTLS.

Quote
2) also.... i thought this was a lower mass mission, so they would have even more fuel left than they did previously like with thaicom?   for eutelsat they didn't do a boost back, so they should've had even more fuel to slow down, no?
I don't recall whether Thiacom-8 was a supersynchronous GTO injection, but this one was. Supersynchronous takes the apogee past GTO distance, far enough that the period of the elliptic orbit is 24 hours. Takes more dV than a simple GTO.

As far as pushing the envelope is concerned, I think they will cut their margins as close as possible, even if they have some reserve propellant, in order to find their system's breaking point.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: feynmanrules on 06/15/2016 06:01 pm

Quote
I don't think any of the GTO missions had boost-back burns.  the last one certainly did not.

you're right, i just checked ses and thaicom and neither mentioned it.   i guess the lack of boost back was just emphasized more during this attempt.  my bad, thanks for clarifying that makes much more sense.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/15/2016 06:03 pm
Yeah, no boost-back burns on any of the GTO missions.  The ASDS has been positioned nearly identically for each mission, BTW -- so each of the GTO missions is using basically the same trajectory for stage recovery.  No boost-back on one, no boost-back on any of them.

Second, yeah, this mission did launch a little less mass to GTO than a few earlier missions, so yeah, it should have had a little better fuel margin.  So, unless there was some fuel issue during initial boost that no one has mentioned, I'd have to say that the one engine not ramping up to full thrust was more likely to have been an issue with damage to the engine from entry, as opposed to any kind of fuel depletion.

And, of course, I always have an issue with fuel depletion causing only one engine to fail.  If fuel depletion is the issue, I would expect all engines to falter simultaneously.  That didn't happen on SES-9, and doesn't appear to have happened today...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gadgetmind on 06/15/2016 06:28 pm
That time it landed, caught fire, and fell over

Hmm, Swamp Castle from Monty Python and the Holy Grail?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Herb Schaltegger on 06/15/2016 06:37 pm

And, of course, I always have an issue with fuel depletion causing only one engine to fail.  If fuel depletion is the issue, I would expect all engines to falter simultaneously.  That didn't happen on SES-9, and doesn't appear to have happened today...

I think turbulent flow-induced variances plus those induced by body rates during descent/landing would almost guarantee some difference in flameout performance if he tanks run low enough.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 06:54 pm

And, of course, I always have an issue with fuel depletion causing only one engine to fail.  If fuel depletion is the issue, I would expect all engines to falter simultaneously.  That didn't happen on SES-9, and doesn't appear to have happened today...

I think turbulent flow-induced variances plus those induced by body rates during descent/landing would almost guarantee some difference in flameout performance if he tanks run low enough.
Instability or low thrust because of gas ingestion is a "chaotic" thing.  If the condition is marginal, I think you'd expect a "stochastic" result.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: John Alan on 06/15/2016 07:11 pm
How about...  ;)
Low engine thrust due to a leaking RP-1 fuel line into the gas generator on one engine... post reentry...

Fuel leaking everywhere causes the fire seen... this landing and the one 2 launches back...  :o
The gas generator running lean causes low pump speed and possibly melted the gas turbine..
Result is low engine thrust... causing RUD upon impact of the "firm" nature...  ::)

Just waving my arms here... in speculation WTF went wrong...  :P
 ;D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/15/2016 07:14 pm

And, of course, I always have an issue with fuel depletion causing only one engine to fail.  If fuel depletion is the issue, I would expect all engines to falter simultaneously.  That didn't happen on SES-9, and doesn't appear to have happened today...

I think turbulent flow-induced variances plus those induced by body rates during descent/landing would almost guarantee some difference in flameout performance if he tanks run low enough.
Instability or low thrust because of gas ingestion is a "chaotic" thing.  If the condition is marginal, I think you'd expect a "stochastic" result.

Not sure I understand your distinction. Herb's hypothesis could plausibly result in seemingly random (stochastic) outcomes, ie with marginal fuel levels, sometimes you get a flameout and sometimes you don't (which presumably has been the case with F9)  but you can't predict exactly when or which engine.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: punder on 06/15/2016 07:17 pm
That time it landed, caught fire, and fell over

Hmm, Swamp Castle from Monty Python and the Holy Grail?

Absolutely. Monty Python is the modern Shakespeare, Milton and Johnson rolled into... well, a few guys.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/15/2016 07:27 pm

And, of course, I always have an issue with fuel depletion causing only one engine to fail.  If fuel depletion is the issue, I would expect all engines to falter simultaneously.  That didn't happen on SES-9, and doesn't appear to have happened today...

I think turbulent flow-induced variances plus those induced by body rates during descent/landing would almost guarantee some difference in flameout performance if he tanks run low enough.
Instability or low thrust because of gas ingestion is a "chaotic" thing.  If the condition is marginal, I think you'd expect a "stochastic" result.

Not sure I understand your distinction. Herb's hypothesis could plausibly result in seemingly random (stochastic) outcomes, ie with marginal fuel levels, sometimes you get a flameout and sometimes you don't (which presumably has been the case with F9)  but you can't predict exactly when or which engine.
I was addressing the OP, one up.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Semmel on 06/15/2016 07:30 pm
In the deimos image in the update thread, it looks like there is a scorch mark to the lower left. Or is it a shadow of the stage still standing?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CJ on 06/15/2016 07:38 pm
Regarding the fire seen;

If the F9 landed very hard (due to the engine issue, or any other reason), beyond the margins for the crush cores, where would the load go? IMHO, it'd push the upper leg attach points inward, and that could rupture the lower tank (LOX RP1) and perhaps other things too. That's my guess as to the source of the flames and the loss of the F9. 

Judging the the reactions of the SpaceX crowd at Hawthorne, my guess is they had some sort of indication (perhaps just a clue, not a certainty) of failure that we didn't. I also suspect that our vid feed is delayed a few seconds, to make sure they don't inadvertently webcast an ITAR item. 

I do want to commend and thank SpaceX for being so speedily forthcoming with info and vids. Though it sure seemed like they left us hanging forever on the fate of the F9, it was, in reality, only minutes.

Edit: I got it backwards; the LOX tank is on the other end. Fixed. Oh well, I'd have been right if the F9 had landed inverted.  :)
 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ZachS09 on 06/15/2016 07:41 pm
How long from now will SpaceX release launch photos from remote cameras?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lars-J on 06/15/2016 07:55 pm
How long from now will SpaceX release launch photos from remote cameras?

They already have: https://www.flickr.com/photos/spacex/
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Fan Boi on 06/15/2016 08:11 pm
I have watched the landing video several times now and it sure appears that it landed upright and was sitting there on it's legs, burning. It sure doesn't look like it punched through the ship or tipped over. Can't wait to see better video because I am confused about this landing...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: FinalFrontier on 06/15/2016 08:13 pm
An image from Deimos 2 40 minutes after the rough landing. Probably wreckage on the ASDS, one of the support ships in the lower right corner and clouds or smoke in the top left corner:

(http://i.imgur.com/YDKVS1g.jpg)

Source: https://twitter.com/deimosimaging/status/743153542362439680

Touched it up a bit

Looks like a piece made it. Wonder if there is anything usable you can strip off.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ZachS09 on 06/15/2016 08:32 pm
What was the amount of fuel reserve in the first stage upon MECO-1 at 156 seconds MET?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ZachS09 on 06/15/2016 08:35 pm
Also, what was the parking orbit perigee and apogee after SECO-1?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mvpel on 06/15/2016 08:38 pm
One of the unsung advantageous of the latest upgrades is that the launches no longer "look slow."

CRS-8 was my first in-person launch viewing, and having had a viewing diet of ballistic missile interceptor launches during flight tests, I found it looked gloriously, impossibly slow. With an SM-3 atop an MK-72 booster, the thing's practically out of sight before the kid who pushed the launch button finishes saying "Eagle's away! Eagle's away!"  ;D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Antares on 06/15/2016 08:41 pm
The rud occurred less than 5 minutes before they identified and started to rectify the problem.

Not really.  A more accurate interpretation would be that SpaceX knew there is a weakness to the experimental landing and has been working to correct it in the development spiral.  However, there's no reason to hold up launches, which is what matters to paying customers (who aren't yet paying reduced prices for reflight), to design out the weakness.  The system seems robust for ascent cases and good for ~80% of descent cases.  This time, for whatever reason, loads or temperatures or whatever swung the descent mission into one of those corner cases.

One could make the case this is a more robust process because it manages the real risk (mission success of the paying customer) and keeps the revenue stream flowing while not fearing the kickback of a RUD live on YouTube.  Those focused on the technical side may not like it, but it allows for the most rapid innovation and is truly what sets SpaceX apart from the others and especially from the government.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/15/2016 09:03 pm
Also, what was the parking orbit perigee and apogee after SECO-1?
The reading showed 27436 km/h and 165 km. Assuming that this includes the kick from Earth's rotation, that's 7,621 m/s. Solve for specific orbital energy and you should be set.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/15/2016 09:32 pm
What was the amount of fuel reserve in the first stage upon MECO-1 at 156 seconds MET?

Let us know when Elon shares that with you.  ;)

Meanwhile, this estimate by LouScheffer from a previous launch is a good starting point:

http://forum.nasaspaceflight.com/index.php?topic=40256.msg1539728#msg1539728
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gospacex on 06/15/2016 09:38 pm
One of the unsung advantageous of the latest upgrades is that the launches no longer "look slow."

CRS-8 was my first in-person launch viewing, and having had a viewing diet of ballistic missile interceptor launches during flight tests, I found it looked gloriously, impossibly slow. With an SM-3 atop an MK-72 booster, the thing's practically out of sight before the kid who pushed the launch button finishes saying "Eagle's away! Eagle's away!"  ;D

Compared to insane projects from 1970...

https://www.youtube.com/watch?v=YZZV464z9g8

100g in boost phase. IIRC 1st stage burnoff in 2 seconds!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Robotbeat on 06/16/2016 12:20 am
One of the unsung advantageous of the latest upgrades is that the launches no longer "look slow."

CRS-8 was my first in-person launch viewing, and having had a viewing diet of ballistic missile interceptor launches during flight tests, I found it looked gloriously, impossibly slow. With an SM-3 atop an MK-72 booster, the thing's practically out of sight before the kid who pushed the launch button finishes saying "Eagle's away! Eagle's away!"  ;D

Compared to insane projects from 1970...

https://www.youtube.com/watch?v=YZZV464z9g8

100g in boost phase. IIRC 1st stage burnoff in 2 seconds!
Holy crap!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: deruch on 06/16/2016 02:59 am
I noticed a change in the start-up procedure.  It used to be that they started the water deluge system (Niagara) at T- ~6s.  But now it is being started at T- ~11s.  My assumption is that this is to allow it more time to reach full flow and thus maximum protection.  In going back to look at previous launches, I saw that the earlier deluge activation was also done on the Thaicom-8 launch but I couldn't tell about JCSAT-14.  The camera angles shown made it hard to see anything.  CRS-8 was definitely with the T-6s, though.

Also, this was the first launch I noticed that there seemed to be some sort of liquid running from the hold downs.  I'm guessing this was water and was meant to help protect them against damage from exhaust impingement but if so it was running well before ignition. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Robotbeat on 06/16/2016 04:42 am
I noticed a change in the start-up procedure.  It used to be that they started the water deluge system (Niagara) at T- ~6s.  But now it is being started at T- ~11s.  My assumption is that this is to allow it more time to reach full flow and thus maximum protection.  In going back to look at previous launches, I saw that the earlier deluge activation was also done on the Thaicom-8 launch but I couldn't tell about JCSAT-14.  The camera angles shown made it hard to see anything.  CRS-8 was definitely with the T-6s, though.

Also, this was the first launch I noticed that there seemed to be some sort of liquid running from the hold downs.  I'm guessing this was water and was meant to help protect them against damage from exhaust impingement but if so it was running well before ignition.
Also, could simply allow more water to be laid down. Saturate the whole area.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Dante80 on 06/16/2016 04:53 am

I don't recall whether Thiacom-8 was a supersynchronous GTO injection, but this one was. Supersynchronous takes the apogee past GTO distance, far enough that the period of the elliptic orbit is 24 hours. Takes more dV than a simple GTO.

05/27/16 Falcon 9 v1.2 F9-25 Thiacom 8 CC 40 350x90226x21.2 GTO+
06/15/16 Falcon 9 v1.2 F9-26 Eutelsat 117WB/ABS2A CC 40 395x62750x24.68 GTO+
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: guckyfan on 06/16/2016 05:18 am
I don't usually comment on typos. But it is Thaicom not Thiacom. It is a Thai satellite. How would you like USA spelled UAS?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/16/2016 05:56 am

I don't recall whether Thiacom-8 was a supersynchronous GTO injection, but this one was. Supersynchronous takes the apogee past GTO distance, far enough that the period of the elliptic orbit is 24 hours. Takes more dV than a simple GTO.

05/27/16 Falcon 9 v1.2 F9-25 Thiacom 8 CC 40 350x90226x21.2 GTO+
06/15/16 Falcon 9 v1.2 F9-26 Eutelsat 117WB/ABS2A CC 40 395x62750x24.68 GTO+

Yup, Thaicom-8 was more supersynchronous. I suspect that was SpaceX's highest velocity launch to date with the exception of DSCOVR which was launched to the Earth-Sun L1 point.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Dante80 on 06/16/2016 06:04 am
Yup, Thaicom-8 was more supersynchronous. I suspect that was SpaceX's highest velocity launch to date with the exception of DSCOVR which was launched to the Earth-Sun L1 point.

The Thaicom 8 targeted orbit was the same as the Thaicom 6 launch that v1.1 did back in 2014. This btw showed the evolution from v1.1 to FT. In the Thaicom 6 campaign, the profile was fully expendable and lower than planned fuel reserves were reported at end of final Stg2 burn.

This time, the profile was for DPL, the sat got a slightly better insertion with no S2 reisdual problems, and the stage landed.


 BTW, I think that todays' launch reached an even higher velocity at MECO.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/16/2016 06:29 am
Oh, I was referring to payload velocity, not first stage separation velocity. As you say, because of differences in Falcon 9 version it's hard to precisely deduce the separation velocity from the final payload orbit.

You say this was the highest first stage separation velocity then?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 07:31 am
I watched this video at .25 speed and frame per frame from (9:34-9:40) vehicle looks upright with some flames outlining left leg and tank. No idea if she remained that way or fell over after. Have a look...

https://www.youtube.com/watch?v=PcsBCh-ypFM
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: saliva_sweet on 06/16/2016 08:46 am
FWIW, it should now start to be possible to start calculating the statistical likelihood of a Stage-1 recovery from a GTO launch based against target orbit and dV usage by the stage. We're still a very long way from cast iron numbers but the general shape should now just begin to be apparent.

Here's a plot of all F9 GTOs to date. Black line is regression through F9 1.1 flights. Red line is for F9 1.2 flights. Red dots are successful recoveries. Both successful recoveries are below the red line and both failed ones are above it. It also looks like this may indeed have been the hardest landing so far.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: guckyfan on 06/16/2016 09:21 am
I was thinking of that coming upgrade capable of dealing with a thrust deficit of one engine. Could that be just the next thrust upgrade, enabling the two engines running without problems to compensate?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: TheTraveller on 06/16/2016 10:45 am
I watch this video at .25 speed and frame per frame from (9:34-9:40) vehicle looks upright with some flames outlining left leg and tank. No idea if she remained that way or fell over after. Have a look...

Sure seems to be a lot of flames. Maybe the hard landing broke a fuel line or ruptured a fuel tank and then RUD?

Did land and stayed vertical, so they at least achieved that.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cuddihy on 06/16/2016 11:11 am
I was thinking of that coming upgrade capable of dealing with a thrust deficit of one engine. Could that be just the next thrust upgrade, enabling the two engines running without problems to compensate?

Due to taking the rest of the year to implement, it's probably a bit more substantial -- my bet: improved sensor positioning & response on throttles & gimbals as well as software to both speed up the recognition there's a low thrust condition & speed up the gimbal & thrust increase on other engines to compensate.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 11:37 am
I watch this video at .25 speed and frame per frame from (9:34-9:40) vehicle looks upright with some flames outlining left leg and tank. No idea if she remained that way or fell over after. Have a look...

Sure seems to be a lot of flames. Maybe the hard landing broke a fuel line or ruptured a fuel tank and then RUD?

Did land and stayed vertical, so they at least achieved that.
Great vidcap, that's is exactly what I saw. She could be still standing tall as far as we know... ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 11:56 am
I was thinking of that coming upgrade capable of dealing with a thrust deficit of one engine. Could that be just the next thrust upgrade, enabling the two engines running without problems to compensate?

Due to taking the rest of the year to implement, it's probably a bit more substantial -- my bet: improved sensor positioning & response on throttles & gimbals as well as software to both speed up the recognition there's a low thrust condition & speed up the gimbal & thrust increase on other engines to compensate.

And -- to address the elephant in the room -- what good does it do to increase thrust on the remaining two engines if one of your engines has either shut down or failed to come up to thrust because you're running out of fuel?

I wouldn't think any adjustment to the thrust of the remaining two engines would help, if the issue is your fuel state...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/16/2016 11:59 am
What if the upgrades Musk mentioned are not to the engines but the landing legs. You know, that old idea of using the legs as additional drag surfaces.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 12:20 pm
There are still center of pressure issues with a stage free-falling with its legs deployed.  I'm not saying it's not possible, just that it makes active attitude control a lot more of a dicey prospect.

Using the legs as speed brakes would reduce the propulsive requirement a bit, true.  Someone else would have to run the math to see how much dirtying-up the stage aerodynamically like that (rather like deploying flaps on a landing airliner) reduces its terminal velocity.

I also just want to caution people not to make every single thing Elon Musk has ever said the tent poles of their reality.  Let's face it -- when speaking off the cuff, Elon exaggerates a lot, and has a lot of mental flights of fancy that he can't keep himself from speculating about.  And because of his position as the visionary leader of SpaceX, these tend to be reported in the media as the concrete plans of SpaceX going forward.

Recall, for example, that Elon stated after the CRS-8 stage recovery that that stage would be brought back to the Cape, test-fired 10 times on the pad, and then re-used to launch another orbital mission by June.  The CRS-8 booster is one of the cleanest yet recovered.  And it's not going to be re-used until at least September, if not later.

Just sayin', the legal defense of "well, Elon said this two years ago" doesn't win the day very often, at least not from a real-world point of view... ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/16/2016 12:20 pm
I was thinking of that coming upgrade capable of dealing with a thrust deficit of one engine. Could that be just the next thrust upgrade, enabling the two engines running without problems to compensate?
That was my thinking. Simplest possibly way to interpret what he said and all that. We already know about the thrust upgrade and the time frame matches up.

I wonder if the root cause here isn't helium bubbles or low propellent but rather startup in "retropropulsion mode" with full atmospheric pressure pushing back against startup.  It could be that they are saying some transient thrust fluctuations on startup, and that currently they don't have enough thrust margin to compensate.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Antilope7724 on 06/16/2016 12:24 pm
I don't usually comment on typos. But it is Thaicom not Thiacom. It is a Thai satellite. How would you like USA spelled UAS?

I prefer the Untied States.  ;D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 12:27 pm
I don't usually comment on typos. But it is Thaicom not Thiacom. It is a Thai satellite. How would you like USA spelled UAS?

I prefer the Untied States.  ;D

Dyslexics of the world, untie!   :D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/16/2016 12:56 pm
There are still center of pressure issues with a stage free-falling with its legs deployed. 

My assumption is that they wouldn't deploy them in freefall, but during the landing burn, just a little bit earlier than it happens now, in a regime where it would provide a useful drag delta-V. As such, the engine(s) would have control authority. This way, there could be an additional way to fine-tune the landing deceleration if one engine runs at low thrust - deploy the legs slightly earlier in the burn. Heck, just deploying them at the same time each time will produce bigger results the bigger the airspeed (or underburn if you want to look at it that way) at that moment is, but this is contingent on the legs being able to handle the loads. Which the current leg design can't support.

Besides, the center of pressure isn't determined only by the leg position, there's also a really long, cylindrical body that would tend to stabilize the stage in the airflow.

Someone else would have to run the math to see how much dirtying-up the stage aerodynamically like that (rather like deploying flaps on a landing airliner) reduces its terminal velocity.

I believe SpaceX said after F9R tests in Texas that the deployed legs do provide useful delta-v, but at the expense of getting cooked more.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: tjchambers on 06/16/2016 02:38 pm
I infer that depending on WHICH engine was low on thrust would have a large effect on your ability to manage directionality around the center of mass? The center engine being low having the least impact, but either outer engines needing more swiveling compensation? Am I thinking about that properly?

I do realize that there is a very long vertical mass above the engines.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kaputnik on 06/16/2016 02:54 pm
It has been speculated (or proven?) that the centre engine has greater gimbal range. Maybe increasing the gimbal range on the other two landing engines would be useful?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/16/2016 02:58 pm
Increasing gimbal range would "only" allow you to avoid an uncontrollable torque on the stage, but from the landing apparently being pretty much a bullseye I'm not inclined to think the thrust differential was large enough to cause control issues.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: tjchambers on 06/16/2016 03:07 pm
Increasing gimbal range would "only" allow you to avoid an uncontrollable torque on the stage, but from the landing apparently being pretty much a bullseye I'm not inclined to think the thrust differential was large enough to cause control issues.

I am inferring it was the thrust differential THIS TIME that was not sufficiently large. Could be in the future.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: mme on 06/16/2016 03:08 pm
I was thinking of that coming upgrade capable of dealing with a thrust deficit of one engine. Could that be just the next thrust upgrade, enabling the two engines running without problems to compensate?
That was my thinking. Simplest possibly way to interpret what he said and all that. We already know about the thrust upgrade and the time frame matches up.

I wonder if the root cause here isn't helium bubbles or low propellent but rather startup in "retropropulsion mode" with full atmospheric pressure pushing back against startup.  It could be that they are saying some transient thrust fluctuations on startup, and that currently they don't have enough thrust margin to compensate.
I think you're right.  Everyone is jumping to one of two conclusions: Helium in a feed line or damage.
I doubt it was do to low propellent levels.  The previous example of that was a lawn dart and I think that Elon would have mentioned if it was the exact same root cause as SES-9.

Single engine landings have a lot more time to compensate for variations in engine start up/ramp up time.  My suspicion is it's a more a matter of reacting quickly enough to these variations in start up time and/or take advantage of the upcoming increase in thrust.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 03:15 pm
It has been speculated (or proven?) that the centre engine has greater gimbal range. Maybe increasing the gimbal range on the other two landing engines would be useful?

An outer engine needs a gimbal angle of about 6 degrees from center in order to point its thrust vector through the stage center of mass (with legs deployed) if my geometry is correct, based on this CoM estimate by someone else:

http://space.stackexchange.com/questions/8771/how-stable-would-a-falcon-9-first-stage-be-after-it-has-landed-on-a-barge
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ThereIWas3 on 06/16/2016 03:19 pm
Losing the center engine would result in a symmetrical situation.  An outboard engine loss would be messier
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/16/2016 03:23 pm
An outer engine needs a gimbal angle of about 6 degrees from center in order to point its thrust vector through the stage center of mass (with legs deployed) if my geometry is correct.

That's the worst case scenario, though and would only be relevant if it's only that engine that's firing. With 2 of the 3 engines firing that angle has to be relaxed somewhat. You just need to guarantee that the combined thrust vector of all the engines running doesn't cause a torque, which does not really necessitate *any* engine by itself firing through CoM if it's a symmetric layout. It does help stability in case of engine loss, though.

For example, in normal ascent I'm not seeing any outward angle on the 8 outer engines on v1.1 and later, they appear to be firing parallel to the engine rocket body. On v1.0 there were visual hints in the plume that the engines were firing at a slight outward angle.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 03:24 pm
An outer engine needs a gimbal angle of about 6 degrees from center in order to point its thrust vector through the stage center of mass (with legs deployed) if my geometry is correct.

That's the worst case scenario, though and would only be relevant if it's only that engine that's firing. With 2 of the 3 engines firing that angle has to be relaxed somewhat. You just need to guarantee that the combined thrust vector of all the engines running doesn't cause a torque, which does not really necessitate *any* engine by itself firing through CoM if it's a symmetric layout. It does help stability in case of engine loss, though.

For example, in normal ascent I'm not seeing any outward angle on the 8 outer engines on v1.1 and later, they appear to be firing parallel to the engine body. On v1.0 there were visual hints in the plume that the engines were firing at a slight outward angle.

Agree, 6 degrees is worst-case scenario, and with multi-engine firing, vector angle compensation would need to be less. Maybe already within their existing capability.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 03:41 pm
Everyone is jumping to one of two conclusions: Helium in a feed line or damage.
I doubt it was do to low propellent levels.  The previous example of that was a lawn dart and I think that Elon would have mentioned if it was the exact same root cause as SES-9.

There is more info in L2 about the root cause of the SES-9 failure, worth reading.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsdavis9 on 06/16/2016 05:06 pm
Everyone is jumping to one of two conclusions: Helium in a feed line or damage.
I doubt it was do to low propellent levels.  The previous example of that was a lawn dart and I think that Elon would have mentioned if it was the exact same root cause as SES-9.

There is more info in L2 about the root cause of the SES-9 failure, worth reading.

Ok I searched l2 (as best I could) and all I found was the ses9 thread which said low thrust on one engine. Is there more?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 05:44 pm
Using the legs as speed brakes is interesting but control issues will need addressing for fine adjustments. We are talking about a whole redesign here plus system mass added to S1, not a small thing... Perhaps only two can be used to simplify the system and leave the remaining two as is... Hey, that's whats sims are for! :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 05:54 pm
Everyone is jumping to one of two conclusions: Helium in a feed line or damage.
I doubt it was do to low propellent levels.  The previous example of that was a lawn dart and I think that Elon would have mentioned if it was the exact same root cause as SES-9.

There is more info in L2 about the root cause of the SES-9 failure, worth reading.

Ok I searched l2 (as best I could) and all I found was the ses9 thread which said low thrust on one engine. Is there more?

There really isn't anything in L2 that states anything without a shadow of a doubt in re the SES-9 landing burn failure. In the L2 content, just as on the public threads (so see, I'm not giving out L2 info here), it is strongly suggested to be a result of running out of fuel, same story as was debated here in the public threads (no L2-level information about that), but there was never any reason for that condition given (just the technical condition that caused one engine to fail), so the assumption that it was due to fuel state is just that -- an assumption on our parts.  An assumption I have been roundly and bitterly criticized for questioning, and got an L2 thread shut down for questioning, but still -- just an assumption.

And, by the way, that technical condition has indeed been mentioned in this very -- public -- thread since yesterday's landing burn failure.  I'm being extremely circumspect not mentioning it, now, but it's a symptom of a deeper issue that, as I said above, has been assumed to have been caused by the fuel state.  But even in L2 it is never specifically stated by any SpaceX employee or insider that this condition was caused by fuel depletion, they all left that for us to debate and make assumptions about.

And that was where it stood until yesterday, when we had another landing burn failure rather similar to the SES-9 failure, with far less indication that, this time, it could have been a fuel depletion issue.  As I understand it, the fuel state for the Eutelsat/ABS booster yesterday was as good as, or better than, the fuel states on the last two birds that launched to GTO and had enough fuel to achieve stage recoveries.  That's based on the total mass of the satellites being orbited, the energy required to get them there, and the very similar MECO velocities of each of these flights.

So, had SES-9's engine failure been just a fuel state issue, and if the Eutelsat/ABS booster landing burn failure yesterday was a similar situation and could be corrected by more quickly ramping up thrust to other engines, then I have to ask again, what good is it to ramp up thrust on your remaining two engines when one engine just cut out due to fuel depletion?  If you just had an engine fail to come up to thrust or fail to continue to burn due to your fuel state, wouldn't ramping up thrust to the other engines cause them to suffer the same issue almost immediately?

Any tweaking SpaceX might need to do, if these landing burn failures occurred due to fuel depletion, would have to be aimed at improving your fuel state as you begin your landing burn.  I don't know about anyone else, but I can't read that into Musk's tweet yesterday in re tweaking the stages to compensate for one engine failing to come up to thrust.  You would have to be desperate to support your pet theory of fuel depletion to read anything at all about fuel state into that tweet.

So, while I will agree that it's not a bipolar argument -- it doesn't have to be either fuel depletion or entry heating damage -- it's good to see that others here are finally beginning to believe that there are (to answer a question Lou put to me some time back) possible reasons for a landing burn to fail other than fuel state.  And that SpaceX is now looking into how to compensate if one of these non-fuel-state issues happens during future landing burns.

Just my take on it.  YMMV.  :)

Edited for typos and for calling the bird flown yesterday Thaicom-8... sigh... I still blame the pain pills.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kaputnik on 06/16/2016 05:56 pm
Just a nit, Thaicom 8 landed just fine...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kevin-rf on 06/16/2016 06:08 pm
Just a nit, Thaicom 8 landed just fine...
Last I checked, Thaicom 8 is still in orbit.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 06:09 pm
Just a nit, Thaicom 8 landed just fine...

Fixed, thanks... sigh...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 06:13 pm
Oh, and to repeat properly in the discussion thread a question I accidentally posted into the update thread (I guess because that's where I found the tweet to quote) and found it deleted, because it's NOT an update -- in re Musk tweeting yesterday morning that the full landing video would be posted "later today" once the guys got to the droneship...

Is it "later today" in Elon time yet?  :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Semmel on 06/16/2016 06:15 pm
Doug, if it gives you any peace, I am on your side. We never had any evidence that supports fuel depletion. But I also find it rather mute to argue against the most vocal opinion voicers that ignore the lack of evidence.

I hope musks tweet puts an end to it. An engine underperformance is pretty interesting. Also the solution to the problem is. Since the tweet indicates a chance in engine, plumbing or octoweb design, the cause might be some unexpected atmospheric effects during reentry. Makes me very curious what that might be.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 06:21 pm
Quote
So, had SES-9's engine failure been just a fuel state issue, and if the Eutelsat/ABS booster landing burn failure yesterday was a similar situation and could be corrected by more quickly ramping up thrust to other engines, then I have to ask again, what good is it to ramp up thrust on your remaining two engines when one engine just cut out due to fuel depletion?  If you just had an engine fail to come up to thrust or fail to continue to burn due to your fuel state, wouldn't ramping up thrust to the other engines cause them to suffer the same issue almost immediately?

If the low-thrust condition is a random result of a low propellant level that allows occasional bubbles of helium into one of the turbopumps, the other engines can still run at full thrust until/unless another random bubble is ingested. So far it seems the low-thrust condition has affected only one engine (SES-9, and the most recent launch) during the landing burn. It may be that the propellant feed line geometry makes one engine more susceptible than the others to gas bubble ingestion.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 06:24 pm
Quote
We never had any evidence that supports fuel depletion.

There's a definitive statement on L2 about what happened on SES-9, which I take at face value given the poster's location and familiarity with F9 evidenced in his previous posts.

A more accurate statement on your part might be, "There's a post on L2 by someone who claims to know what happened on SES-9, but I don't believe him because he hasn't disclosed his source." Not quite the same thing as "no evidence."

https://forum.nasaspaceflight.com/index.php?topic=39345.msg1503255#msg1503255
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 06:26 pm
How do we know it's a fuel issue? It could be a LOX issue or turbopump, valve, controller etc... Just sayin'... ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/16/2016 06:42 pm
How do we know it's a fuel issue?

We don't.

I suspect that if it were merely a fuel/LOX depletion issue SpaceX would say so.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 06:49 pm
How do we know it's a fuel issue? It could be a LOX issue or turbopump, valve, controller etc... Just sayin'... ;)

Just to be clear, no one is arguing it's fuel or LOX per se. "Fuel" here was someone's shorthand for "propellant."

The question being debated is whether there's any evidence for the hypothesis that low propellant levels are a factor in the low-thrust anomaly during landing, eg making it possible for helium bubbles to enter the feed line(s) and cause one of the engines to lose thrust.

In this discussion, some people may have resorted to "low fuel level" as a shorthand, but the question is really about low "propellant" levels and whether or not that may be a contributing factor.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/16/2016 06:52 pm
Quote
We never had any evidence that supports fuel depletion.

There's a definitive statement on L2 about what happened on SES-9, which I take at face value.

A more accurate statement on your part might be, "There's a post on L2 by someone who claims to know what happened on SES-9, but I don't believe him because he hasn't disclosed his source." Not quite the same thing as "no evidence."

https://forum.nasaspaceflight.com/index.php?topic=39345.msg1503255#msg1503255

I would not say there are statements by SpaceX insiders that I don't believe.  I would say we were told of a condition, by a reliable source, that could have more than one possible root cause, with no additional data on which root cause SpaceX thought was at fault.  I have then questioned the assumption of which possible root cause was, in fact, responsible for the condition.  That's all.

Ah, well... it's been sort of nice, while recovering, being able to sit and noodle on the forum whenever I felt like it.  But, seven weeks after being rolled into the ER for emergency surgery, today is the day when I actually start back working at my job (only half-time for the next couple of weeks).  Still on the happy pills, no way around that at this point, but capable of answering phones and explaining things to my customers.  So, I'll be back later... :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 06:54 pm
Quote
I would not say there are statements by SpaceX insiders that I don't believe.  I would say we were told of a condition, by a reliable source, that could have more than one possible root cause, with no additional data on which root cause SpaceX thought was at fault.  I have then questioned the assumption of which possible root cause was, in fact, responsible for the condition.  That's all.

Thanks for clarifying. Yes, there was more than one root cause suggested in that post and I understand your caution in assuming either one or the other was in fact the true cause.

It may be worth noting that the two suggested root causes may be synergetic, ie *both* conditions can interact and cause the phenomenon resulting in low thrust, so it may be impossible to say which condition was more at fault.

Quote
But, seven weeks after being rolled into the ER for emergency surgery, today is the day when I actually start back working at my job (only half-time for the next couple of weeks).  Still on the happy pills, no way around that at this point, but capable of answering phones and explaining things to my customers.  So, I'll be back later...

Welcome back to life, and please share your happy pills if you have any extras.  ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ChrisC on 06/16/2016 06:57 pm
From the update thread:

USLaunchReport:  One of the three Merlin engines did not fire properly on Boost Back.

Thought there was no "Boost Back" burn on this mission, but only Re-entry Burn and Landing Burn.  Wasn't the problem with one of 3 engines on the Landing Burn?

I guess this means we should take USLR with a Wite-Out bottle full of salt.  I love and greatly appreciate their video reports, but this mis-quote (or whatever it is) tells me to not look beyond their raw footage.  At least not for now while they are still new at this.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: starhawk92 on 06/16/2016 07:02 pm
If the low-thrust condition is a random result of a low propellant level that allows occasional bubbles of helium into one of the turbopumps, the other engines can still run at full thrust until/unless another random bubble is ingested. So far it seems the low-thrust condition has affected only one engine (SES-9, and the most recent launch) during the landing burn. It may be that the propellant feed line geometry makes one engine more susceptible than the others to gas bubble ingestion.

There was a launch this year which was scrubbed because of a sputter in the engine, I'll have to check the scrubs thread.  But I think that occurrence rules out low-fuel/low-propellant being the only cause of reduced power on an engine startup.

Edit: 
The following is copied from the Scrubs Thread:


Falcon 9 Flight 22 - SES-9 (not verified)
payload mass: 5,271 kilograms, orbit: geosynchronous, delivered orbit: 334 x 40648 km x 27.96° [65], [69]
  F) 2016-02-22, Successful static fire [64]
  D) 2016-02-24, 24h delay to ensure liquid oxygen temperatures are as cold as possible in an effort to maximize performance of the vehicle (due to high winds) [66]
  C) 2016-02-25, Scrub at T-1:41, LOX loading issues [65]
  R) 2016-02-28, Delay, wayward boat got into range [65]
  C) 2016-02-28, Scrub at T-0, aborted on low thrust alarm. Rising oxygen temps due to hold for boat and helium bubble triggered alarm [65]
  D) 2016-03-01, Delay due to extreme high altitude wind shear [68]
  L) 2016-03-05, Successful launch (the one with the difficult landing attempt) [65]
  BL) 2016-03-05, Hard landing on the ASDS (3 engine landing burn, run out of propellant, no boostback burn) [65][74]


Edit of Edit:
If only I were as quick as Kabloona!!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 07:06 pm
If the low-thrust condition is a random result of a low propellant level that allows occasional bubbles of helium into one of the turbopumps, the other engines can still run at full thrust until/unless another random bubble is ingested. So far it seems the low-thrust condition has affected only one engine (SES-9, and the most recent launch) during the landing burn. It may be that the propellant feed line geometry makes one engine more susceptible than the others to gas bubble ingestion.

There was a launch this year which was scrubbed because of a sputter in the engine, I'll have to check the scrubs thread.  But I think that occurrence rules out low-fuel/low-propellant being the only cause of reduced power on an engine startup.

That was SES-9, too.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsdavis9 on 06/16/2016 07:12 pm
So maybe the fix is better insulation so the lox doesn't warm up.

Might be only insulation on the pipes.

I also like the geometry possibility for bubble rejection.

Don't they have separaters for bubbles. I have one on my forced hot water system. Not sure how it can reliably collect the bubbles. And it probably doesn't work at the velocity and volume that spacex does in their engines.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: starhawk92 on 06/16/2016 07:19 pm
That was SES-9, too.

Man, what a harsh corner for the engineering team -- the only time it happens the rocket explodes.  Maybe parts and pieces of 8 engines mixed up to look at for any help, otherwise what?

This seems to be one of those hurdles which makes rocket science as hard as Rocket Science!!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: tjchambers on 06/16/2016 07:22 pm
I will probably be blasted for lack of knowledge here, but I have a question.

Does the first stage rotate/spin in attempt to reduce the needed engine gimbal angles and more directly use the thrust to reduce speed during the "parabolic" arc it is making towards it's destination? By spin I don't mean continually, just using spinning as a mechanism to better utilize the thrust of the 3 engines which are in some orientation - vertical? horizontal? - relative to the arc.

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 07:23 pm
Quote
Maybe parts and pieces of 8 engines mixed up to look at for any help, otherwise what?

Telemetry from the engines, LOX temp sensors, etc. I expect they have a pretty good idea what happened on the landing burn.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: MattMason on 06/16/2016 07:25 pm
I will probably be blasted for lack of knowledge here, but I have a question.

Does the first stage rotate/spin in attempt to reduce the needed engine gimbal angles and more directly use the thrust to reduce speed during the "parabolic" arc it is making towards it's destination? By spin I don't mean continually, just using spinning as a mechanism to better utilize the thrust of the 3 engines which are in some orientation - vertical? horizontal? - relative to the arc.

Welcome!

Falcon 9 does not use spin stabilization in either launch or landing mode.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsdavis9 on 06/16/2016 07:25 pm
Quote
Maybe parts and pieces of 8 engines mixed up to look at for any help, otherwise what?

Telemetry from the engines, LOX temp sensors, etc. I expect they have a pretty good idea what happened on the landing burn.

Thats my guess. They know what the problem is. The fix they have in mind is going to take some changes in shapes of things. Therefore later this year when the fix can get thru the supply line.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Stan-1967 on 06/16/2016 07:30 pm
So maybe the fix is better insulation so the lox doesn't warm up.

Might be only insulation on the pipes.

I also like the geometry possibility for bubble rejection.

Don't they have separaters for bubbles. I have one on my forced hot water system. Not sure how it can reliably collect the bubbles. And it probably doesn't work at the velocity and volume that spacex does in their engines.

I believe I recall the issue of helium bubbles on SES-9 was postulated to be due to the time the LOX propellant was at superchilled temperature.   The helium is soluble in the LOX, so the longer it sits on the pad with tanks pressurized, the more helium that dissolves into the LOX.   That launch had several "holds" due to a stray boat in the launch zone.   When the He saturated LOX goes through the pump, the helium can then bubble out of the LOX from cavitation effects.   

Where I am going with this is that the SES-9 thrust issues are probably separate from the fuel starvation issues with hoverslam landings.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsdavis9 on 06/16/2016 07:31 pm
Bubble separator in action.

https://www.youtube.com/watch?v=Q3DciFrPqv0
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JamesH65 on 06/16/2016 07:32 pm
I will probably be blasted for lack of knowledge here, but I have a question.

Does the first stage rotate/spin in attempt to reduce the needed engine gimbal angles and more directly use the thrust to reduce speed during the "parabolic" arc it is making towards it's destination? By spin I don't mean continually, just using spinning as a mechanism to better utilize the thrust of the 3 engines which are in some orientation - vertical? horizontal? - relative to the arc.

Welcome!

Falcon 9 does not use spin stabilization in either launch or landing mode.

Poster specifically said not for stabilisation, but, in my reading, was talking about spinning the stage to orient/align the 3 engines either horizontally or vertically relative to the barge.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 07:43 pm
I will probably be blasted for lack of knowledge here, but I have a question.

Does the first stage rotate/spin in attempt to reduce the needed engine gimbal angles and more directly use the thrust to reduce speed during the "parabolic" arc it is making towards it's destination? By spin I don't mean continually, just using spinning as a mechanism to better utilize the thrust of the 3 engines which are in some orientation - vertical? horizontal? - relative to the arc.

Good question. From a thrust perspective, the stage shouldn't really care which way the 3 engines are oriented during boostback/entry/landing. The delta V gained from any given burn is the same. What matters is the pitch/yaw orientation of the stage during a burn, and that attitude should be controllable by the 3 engines  via thrust vectoring in any rotational orientation (or by the center engine only during landing burn).

The rotational orientation is probably more a question of guidance convenience, ie orienting the stage in such a way that IMU or guidance software finds most convenient.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 07:53 pm
Quote
We never had any evidence that supports fuel depletion.

There's a definitive statement on L2 about what happened on SES-9, which I take at face value.

A more accurate statement on your part might be, "There's a post on L2 by someone who claims to know what happened on SES-9, but I don't believe him because he hasn't disclosed his source." Not quite the same thing as "no evidence."

https://forum.nasaspaceflight.com/index.php?topic=39345.msg1503255#msg1503255

I would not say there are statements by SpaceX insiders that I don't believe.  I would say we were told of a condition, by a reliable source, that could have more than one possible root cause, with no additional data on which root cause SpaceX thought was at fault.  I have then questioned the assumption of which possible root cause was, in fact, responsible for the condition.  That's all.

Ah, well... it's been sort of nice, while recovering, being able to sit and noodle on the forum whenever I felt like it.  But, seven weeks after being rolled into the ER for emergency surgery, today is the day when I actually start back working at my job (only half-time for the next couple of weeks).  Still on the happy pills, no way around that at this point, but capable of answering phones and explaining things to my customers.  So, I'll be back later... :)
See ya' soon Doug! :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/16/2016 08:00 pm

Where I am going with this is that the SES-9 thrust issues are probably separate from the fuel starvation issues with hoverslam landings.

Not necessarily: the LOX has had a couple more minutes to be exposed to high pressure helium before the landing burn.  Could well be a combination of factors (G profile during re-entry, helium saturation, warming tank temps, lower propellent levels, supersonic retropropulsion startup issues, etc) combine to trigger the thrust deficit.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Semmel on 06/16/2016 08:01 pm
Quote
We never had any evidence that supports fuel depletion.

There's a definitive statement on L2 about what happened on SES-9, which I take at face value given the poster's location and familiarity with F9 evidenced in his previous posts.

A more accurate statement on your part might be, "There's a post on L2 by someone who claims to know what happened on SES-9, but I don't believe him because he hasn't disclosed his source." Not quite the same thing as "no evidence."

https://forum.nasaspaceflight.com/index.php?topic=39345.msg1503255#msg1503255

I concur,  that was an oversight on my part. Maybe I should have given him more attention to remember him and judge his statement differently.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: jaufgang on 06/16/2016 08:06 pm


I will probably be blasted for lack of knowledge here, but I have a question.

Blasting lack of knowledge on this forum tends to be reserved for statements, not questions.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: spacenut on 06/16/2016 08:16 pm
Would parachutes or inflatable ballons (from excess helium if there is any), help with landings?  Especially the GTO or GSO ones.

Seems like developing the Raptor based metholox upper stage would allow for lower staging to give enough kerolox for controlled landings. 

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 08:17 pm
Quote
We never had any evidence that supports fuel depletion.

There's a definitive statement on L2 about what happened on SES-9, which I take at face value given the poster's location and familiarity with F9 evidenced in his previous posts.

A more accurate statement on your part might be, "There's a post on L2 by someone who claims to know what happened on SES-9, but I don't believe him because he hasn't disclosed his source." Not quite the same thing as "no evidence."

https://forum.nasaspaceflight.com/index.php?topic=39345.msg1503255#msg1503255

I concur,  that was an oversight on my part. Maybe I should have given him more attention to remember him and judge his statement differently.

And I admit his statement is not as authoritative as one from a SpaceXer. But sometimes people who work at the Cape hear things from SpaceXers.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hrissan on 06/16/2016 08:25 pm

Where I am going with this is that the SES-9 thrust issues are probably separate from the fuel starvation issues with hoverslam landings.
Not necessarily: the LOX has had a couple more minutes to be exposed to high pressure helium before the landing burn.  Could well be a combination of factors (G profile during re-entry, helium saturation, warming tank temps, lower propellent levels, supersonic retropropulsion startup issues, etc) combine to trigger the thrust deficit.
Big IMHO here: The fix might be not in engines/plumbing but for example to slowly lower LOX tank pressure after reentry and before landing burn, so that accumulated helium boils off. Post reentry much lower tank stiffness is required due to much lower deceleration.

Similar issues do not seem to affect S2 restart after long coast, so either they do not exist there or solved long ago.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Semmel on 06/16/2016 08:29 pm
I don't know for sure but that does not seem to require an implementation time until the end of the year. Your proposal sounds more like a software update.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/16/2016 08:34 pm

Where I am going with this is that the SES-9 thrust issues are probably separate from the fuel starvation issues with hoverslam landings.
Not necessarily: the LOX has had a couple more minutes to be exposed to high pressure helium before the landing burn.  Could well be a combination of factors (G profile during re-entry, helium saturation, warming tank temps, lower propellent levels, supersonic retropropulsion startup issues, etc) combine to trigger the thrust deficit.
Big IMHO here: The fix might be not in engines/plumbing but for example to slowly lower LOX tank pressure after reentry and before landing burn, so that accumulated helium boils off. Post reentry much lower tank stiffness is required due to much lower deceleration.

Similar issues do not seem to affect S2 restart after long coast, so either they do not exist there or solved long ago.

IMHO, the important clue is Musk's tweet saying the planned upgrades will "compensate" for a low-thrust condition, not prevent it. So it sounds like they think it is not fully preventable, and they have to implement some work-arounds.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/16/2016 08:44 pm

IMHO, the important clue is Musk's tweet saying the planned upgrades will "compensate" for a low-thrust condition, not prevent it. So it sounds like they think it is not fully preventable, and they have to implement some work-arounds.

Well, assuming the problem doesn't happen on CRS missions, one known workaround is "use a lower energy return profile" which *might* translate into "have more propellant margin" (or might not, it could be the G's or heating that is relevant, not the level in the tank).

The thrust upgrade should give the GTO missions more margin, which is a rising tide that will lift all boats.  The margin could be used for boost back to lower re-entry energy, eg, if that's the root cause.

Of course, if they've seen thrust fluctuations on the lower-energy missions as well, but managed to pull off successful landings due to *reasons*, then ignore the paragraphs above. :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/16/2016 08:47 pm
How do we know it's a fuel issue? It could be a LOX issue or turbopump, valve, controller etc... Just sayin'... ;)

Just to be clear, no one is arguing it's fuel or LOX per se. "Fuel" here was someone's shorthand for "propellant."

The question being debated is whether there's any evidence for the hypothesis that low propellant levels are a factor in the low-thrust anomaly during landing, eg making it possible for helium bubbles to enter the feed line(s) and cause one of the engines to lose thrust.

In this discussion, some people may have resorted to "low fuel level" as a shorthand, but the question is really about low "propellant" levels and whether or not that may be a contributing factor.
My comment was in relation to a "low thrust" to be clear... Not RP-1/LOX quantity... It could be flow rate or mixture related etc...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: TrueBlueWitt on 06/16/2016 08:53 pm
Would parachutes or inflatable ballons (from excess helium if there is any), help with landings?  Especially the GTO or GSO ones.

Seems like developing the Raptor based metholox upper stage would allow for lower staging to give enough kerolox for controlled landings.

Let me get this right..You want to come down to try to land on the droneship.. in 40 knot crosswind.. with a balloon or parachute attached to the top?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: schaban on 06/16/2016 08:59 pm
I don't know for sure but that does not seem to require an implementation time until the end of the year. Your proposal sounds more like a software update.

Perhaps they are not going to apply fix to the stages, already in production. There is a lag of about 4 month per stage.

so if they start modification next month, that means 1st updated stage will be ready by November, if not later, when you count time at McGregor...

IMHO...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: virnin on 06/16/2016 09:50 pm
Would parachutes or inflatable ballons (from excess helium if there is any), help with landings?  Especially the GTO or GSO ones.

Seems like developing the Raptor based metholox upper stage would allow for lower staging to give enough kerolox for controlled landings.

Even if deployed subsonic and cut loose before the landing burn, anything sufficiently durable to survive long enough to do any good would likely add significant mass in the interstage.  Fluid dynamics of high-speed parachute deployment are not trivial when it comes to managing the shock load.

But there are threads for discussing booster changes for improved recovery/reusability chances.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: matthewkantar on 06/16/2016 10:05 pm
Regarding weather the stage spins or not, the grid fins do seem to be used to rotate and stop rotation of the stage. The on board views from the F-9 flying test bed in Texas clearly showed the fins being utilized for this. The stage probably has an up/down left/right top/bottom or XYZ directions chosen arbitrarily.

A while back I wondered if spinning the stage up and then spinning back down could be used to burn some velocity off. Then I remembered what a bad effect spining up the propellants on board could have.


Matthew

Edited for rogue word and missing W
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: llanitedave on 06/16/2016 10:13 pm

Where I am going with this is that the SES-9 thrust issues are probably separate from the fuel starvation issues with hoverslam landings.
Not necessarily: the LOX has had a couple more minutes to be exposed to high pressure helium before the landing burn.  Could well be a combination of factors (G profile during re-entry, helium saturation, warming tank temps, lower propellent levels, supersonic retropropulsion startup issues, etc) combine to trigger the thrust deficit.
Big IMHO here: The fix might be not in engines/plumbing but for example to slowly lower LOX tank pressure after reentry and before landing burn, so that accumulated helium boils off. Post reentry much lower tank stiffness is required due to much lower deceleration.

Similar issues do not seem to affect S2 restart after long coast, so either they do not exist there or solved long ago.

It may be that "similar issues" are not really issues for the second stage, since a startup instability of less than a second in the context of a minute-long burn won't have the same consequences that they do when impact with the barge is imminent.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: AC in NC on 06/16/2016 10:30 pm
Would parachutes or inflatable ballons (from excess helium if there is any), help with landings?  Especially the GTO or GSO ones.

From what I've gathered, the 1S landing profile is based on IIP (Instantaneous Impact Point) that is targeted just off the landing zone until the last moment when the stage translates onto the intended landing target.  What this term means is that no matter what happens to the stage, the stage is tracking to impact the exact same point regardless of whether thrust is lost at any particular point.  This was why the stage reorients during entry burn because if it didn't orient upwards to maintain it's position within the landing envelope, the IIP would track off the ASDS and then the stage would have to maneuver back so that IIP was again just off the landing target.

Parachutes, while they *might* well be helpful in bleeding off speed at altitude, but they would be quite unpredictable about how their use would impact the landing trajectory.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Toast on 06/17/2016 12:40 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rcoppola on 06/17/2016 12:42 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Toast on 06/17/2016 12:45 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
I'm assuming the video was slow motion, I was under the impression F9 had to hover slam because it was incapable of hovering. I agree though, it looked a little off in the footage.

Sent from my Nexus 6 using Tapatalk

Edit: I stand corrected! The timestamp shows it's real-time. Definitely something screwy!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lars-J on 06/17/2016 12:45 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.

It is possible one of the three engines lost thrust first, thus causing the rather severe looking angle, so the stage needed down extra time to straighten out - and then ran out of LOX completely.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rcoppola on 06/17/2016 12:46 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
I'm assuming the video was slow motion, I was under the impression F9 had to hover slam because it was incapable of hovering. I agree though, it looked a little off in the footage.

Sent from my Nexus 6 using Tapatalk
I don't think so. The timecode on the bottom right of the video seems to be realtime.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 12:46 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
LOX! ;) Thanks for making right more than just a "stopped clock" for a change... ;D
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Toast on 06/17/2016 12:47 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09

Should help establish an upper limit for recoverable Delta V. Well, until they up the thrust later this year, anyways.

Sent from my Nexus 6 using Tapatalk
Yeh, I just responded to that tweet as it didn't look like the average hover slam. Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
I'm assuming the video was slow motion, I was under the impression F9 had to hover slam because it was incapable of hovering. I agree though, it looked a little off in the footage.

Sent from my Nexus 6 using Tapatalk
I don't think so. The timecode on the bottom right of the video seems to be realtime.
Oh wow, definitely something screwy with the thrust then. Good catch!

Sent from my Nexus 6 using Tapatalk

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/17/2016 12:49 am
Would once again upgrading the F9 to have a slightly higher fuel capacity be worth while? It seems like with a tiny bit more fuel they would be comfortably nailing these GTO missions. Or should they just work on optimizing performance with other upgrades?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: OpelGT on 06/17/2016 12:50 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09
Yeh, I just responded to that tweet as it didn't look like the average hover slam.
Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
I'm assuming the video was slow motion, I was under the impression F9 had to hover slam because it was incapable of hovering. I agree though, it looked a little off in the footage.

https://twitter.com/i/videos/tweet/743602894226653184 (https://twitter.com/i/videos/tweet/743602894226653184) is a direct link to video.

There is a timer in bottom right so I don't think it's a slow-motion video, but it sure is a LONG landing burn!
Maybe they were trying a new landing profile to try and reduce damage to booster
and ran just miscalculated the fuel available?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/17/2016 12:59 am
It doesn't look like it shut down significantly above the deck.  It was going at about the same speed we've seen other stages coming in at, and the engine flame was splaying out onto the deck just before the clouds of smoke billowed out and blocked the view of what was happening.

From the language "accordioned the engines," I'm thinking it hit hard enough for all of the landing gear to stroke completely, which caused the engine bells to come down onto the deck hard.  The center engine was still shutting down, so the backpressure caused the RUD.

I bet the octaweb and the landing legs are still sitting on the deck where they landed...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 01:00 am
Elon just tweeted that the root cause was LOX depletion: https://twitter.com/elonmusk/status/743602894226653184?s=09
Yeh, I just responded to that tweet as it didn't look like the average hover slam.
Look like it got caught in an incorrect T2W at the end as it seems to almost be loitering above the ASDS before running out of LOX.
I'm assuming the video was slow motion, I was under the impression F9 had to hover slam because it was incapable of hovering. I agree though, it looked a little off in the footage.

https://twitter.com/i/videos/tweet/743602894226653184 (https://twitter.com/i/videos/tweet/743602894226653184) is a direct link to video.

There is a timer in bottom right so I don't think it's a slow-motion video, but it sure is a LONG landing burn!
Maybe they were trying a new landing profile to try and reduce damage to booster
and ran just miscalculated the fuel available?
Nice.... 8)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 01:12 am
If you are using Chrome, use the zoom in tool to watch...Looked to be still translating across the deck with the horizontal velocity not all nulled-out yet and hit on one gear low... I'm still impressed with the experiment.. 8).
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ilikeboosterrockets on 06/17/2016 01:27 am
If all the LOX really did run out, then I'd imagine the booster would be much more intact than, say, Jason-3. Think we'll see most of the booster when OCISLY gets back to port?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/17/2016 01:30 am
If you are using Chrome, use the zoom in tool to watch...Looked to be still translating across the deck with the horizontal velocity not all nulled-out yet and hit on one gear low... I'm still impressed with the experiment.. 8).

I do believe you're right.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 01:36 am
If you are using Chrome, use the zoom in tool to watch...Looked to be still translating across the deck with the horizontal velocity not all nulled-out yet and hit on one gear low... I'm still impressed with the experiment.. 8).

I do believe you're right.
Could be a bit of "both of us" from what little we can see. Our eyes and the brains can play tricks on us... :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/17/2016 01:46 am
If all the LOX really did run out, then I'd imagine the booster would be much more intact than, say, Jason-3. Think we'll see most of the booster when OCISLY gets back to port?

I wouldn't hold my breath. Looks like the video stops while the stage is still toppling over, before it hits horizontal and breaks up, so we didn't see the probable final "kaboom."
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: JebK on 06/17/2016 01:49 am
Very interesting.  It looks like it approaches faster but the final landing looks slower!

Compare to CRS-8 landing:https://www.youtube.com/watch?v=sYmQQn_ZSys (https://www.youtube.com/watch?v=sYmQQn_ZSys)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: MrHollifield on 06/17/2016 01:56 am
Looks to me as if the 3-engine burn runs too long and then the center engine is hunting for the right throttle setting to compensate and overshoots by *that* much.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Craig_VG on 06/17/2016 02:14 am
Here's a stabilized version:

https://www.youtube.com/watch?v=p5_hvVbxAAo

From reddit here:

https://www.reddit.com/r/spacex/comments/4ogmvc/elon_musk_on_twitter_looks_like_early_liquid/d4chgzp
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/17/2016 02:32 am
Agreed with the comments above - the LOX got depleted because it "landed too high".

I'm surprised it recovered as well as it did.

There was no explosion shown, and the satellite image seemed to have shown an intact body.   So can they depressurize quickly enough to prevent the pressure explosion?

EDIT: Oh, and in the stabilized version the flare out is so very clear...   Missed it by THAT much!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Tuts36 on 06/17/2016 02:44 am
Agreed with the comments above - the LOX got depleted because it "landed too high".

I'm surprised it recovered as well as it did.

There was no explosion shown, and the satellite image seemed to have shown an intact body.   So can they depressurize quickly enough to prevent the pressure explosion?

EDIT: Oh, and in the stabilized version the flare out is so very clear...   Missed it by THAT much!


It looks to me like the stage is toppling, and the video ends with it at about a 30 degree angle above the deck. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/17/2016 02:51 am
Agreed with the comments above - the LOX got depleted because it "landed too high".

I'm surprised it recovered as well as it did.

There was no explosion shown, and the satellite image seemed to have shown an intact body.   So can they depressurize quickly enough to prevent the pressure explosion?

EDIT: Oh, and in the stabilized version the flare out is so very clear...   Missed it by THAT much!


It looks to me like the stage is toppling, and the video ends with it at about a 30 degree angle above the deck.
Agreed, definitely toppling
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/17/2016 02:59 am
Would once again upgrading the F9 to have a slightly higher fuel capacity be worth while? It seems like with a tiny bit more fuel they would be comfortably nailing these GTO missions. Or should they just work on optimizing performance with other upgrades?

No.  That they need more propellant, they need to refine their trajectory calculations.  They could have put the spacecraft in a slightly lower orbit to have more propellant in the first stage
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/17/2016 04:00 am
Would once again upgrading the F9 to have a slightly higher fuel capacity be worth while? It seems like with a tiny bit more fuel they would be comfortably nailing these GTO missions. Or should they just work on optimizing performance with other upgrades?

No.  That they need more propellant, they need to refine their trajectory calculations.  They could have put the spacecraft in a slightly lower orbit to have more propellant in the first stage
I believe this mission was an easier trajectory though than the last two GTO missions? I could be wrong. But anyway there could also be heavier payloads in the future. I don't see much room for sacrificing on ascent. In my opinion, they need to find other ways to have a larger supply of fuel available for landing. They seem to be walking a tight rope with each GTO mission.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/17/2016 04:06 am
Would once again upgrading the F9 to have a slightly higher fuel capacity be worth while? It seems like with a tiny bit more fuel they would be comfortably nailing these GTO missions. Or should they just work on optimizing performance with other upgrades?

No.  That they need more propellant, they need to refine their trajectory calculations.  They could have put the spacecraft in a slightly lower orbit to have more propellant in the first stage
I believe this mission was an easier trajectory though than the last two GTO missions? I could be wrong. But anyway there could also be heavier payloads in the future. I don't see much room for sacrificing on ascent. In my opinion, they need to find other ways to have a larger supply of fuel available for landing. They seem to be walking a tight rope with each GTO mission.

Like Elon said on twitter today, 2016 is their "year of experimentation."
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Grandpa to Two on 06/17/2016 04:29 am
For sure the stage is falling, looks to be at about 70° seen in the opening of the smoke, screen right. RUD upcoming. Time stamp 10:24:18:01 :-[
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/17/2016 04:50 am
I wonder if there was a mixture ratio issue that made the stage run closer to stoichiometric and bumped up the thrust? (But Merlins run fuel-rich, right?)

Agree with the others: stage looks like it "landed high", and with T/W above one there's not much you can do to recover from that.  It sure did its best attempt at a hover trying, though!

Strange that visual evidence seems to indicate an overthrust condition, not under thrust.  But then again Elon thought the stage hit the deck hard, which is also not the case.  Funny.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: alang on 06/17/2016 04:53 am
Could the response to lox depletion be the stage 'thinking' it is heavier because it is decelerating more slowly and supplying an ever richer mixture and the overall effect being a even lower effective throttle down than designed?
Can depletion mean something other than running out, such as something wrong with a particular engine's pump?
Could they have been experimenting with a centre engine that has an increased throttle range?
Etc.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: guckyfan on 06/17/2016 05:30 am
Could they have been experimenting with a centre engine that has an increased throttle range?
Etc.

I was astounded by seeing the stage practically hover. Yes that implies to me it was very low thrust. That long burn while going down very slowly would deplete the fuel.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/17/2016 05:53 am
This is a fascinating situation.  We've had two sets of tweets and one long-distance video of this stage recovery attempt, and none of them seem to really match up.

I don't believe anyone read the launch day tweets as there having been any issue with propellant depletion.  Those tweets referenced an engine that failed to come up to thrust, and work-arounds being developed to compensate if that happened again, to be available by the end of the year.

Then, today, we get another set of tweets that say well, no, it didn't hit all that hard, but it failed to land due to LOX depletion.

And, also today, we get a video that seems to show the stage coming to a hover above the ASDS, and then come on down a little harder than the successful hoverslams we've seen before, followed by a topple.

Is it just me, or do we seem to have three different things going on here?  A problem with one engine failing to come up to thrust, achieving TW=0 above the deck (which shouldn't happen) and then a LOX depletion (maybe from coming to a hover above the deck and then running out of LOX because that was just the extra half-second of burn time the system didn't have left).

Maybe we did see three different anomalies on this recovery attempt.  They ought not impact the much more error-tolerant RTLS recoveries, but it looks like SpaceX has a few odds and ends to wrap up after this one...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/17/2016 05:58 am
Could they have been experimenting with a centre engine that has an increased throttle range?
Etc.

I was astounded by seeing the stage practically hover. Yes that implies to me it was very low thrust. That long burn while going down very slowly would deplete the fuel.

Exactly.  The sequence of events, to me, looks like:

1. For some unknown reason, they reach hover almost a full stage height above the deck.  I can't see why this would be done on purpose.

2. The stage sits there for too long, burning up fuel as if it RP1 grew on trees.

3. The stage magically recovers, I am not sure how, but begins to descend again, all looks well.

4. As is evident in the stabilized video, the engine flames out just above the deck, and the stage falls down some 20 feet maybe?

5. It sits there for a second with a surprised look on its face, goes "ouch", and then slowly falls over, though appears (from the satellite picture) to have not exploded.

Guesses:

Maybe the "thump" managed to create a pressure outlet that did not result in a skin rupture, and so the stage depressurized without exploding.  It would have made a hell of a wail if it did.

Maybe the recovery from the prolonged hover was by means of an "emergency throttle-down", which already took the engine out of normal operating range, and hence the engine mis-performance information.

----

I don't think anyone on this planet is having more fun in a consequence-free environment than these guys right now are.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: guckyfan on 06/17/2016 06:36 am
Maybe a lot of experimental changes that did not work out on first try. I do not believe the low thrust of the central landing engine was an error. It seemed too well controlled for that. If there was an underperforming engine it was one of the side engines at the beginning of the landing burn. But that was more likely a wrong guess by Elon Musk. The stage did not hit hard as it would through uncontrolled underperformance.

Also note that to me the last moment trajectory changes to hit OCISLY were quite large, even larger than usually and the stage managed that just fine.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ccicchitelli on 06/17/2016 06:48 am
Quote
Maybe a lot of experimental changes that did not work out on first try.

After the stunning, and arguably unexpected, successes so far, it totally makes sense for them to stretch it a bit with this one. They already have one or two more boosters than expected, so why not try something new in the "year of experimentation".
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kaputnik on 06/17/2016 07:07 am
Do we know what the surface windspeed was out there? Just wondering how much of the visible divert was due to crosswind, and how much due to targeting the barge.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: docmordrid on 06/17/2016 07:12 am
What if they're trying to throttle below 40% to give it hover capability? 30-35%, depending on residuals?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kevinof on 06/17/2016 07:13 am
Do we know what the surface windspeed was out there? Just wondering how much of the visible divert was due to crosswind, and how much due to targeting the barge.

From the onboard video it looked very calm. Maybe 10 knots or less.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: ugordan on 06/17/2016 07:15 am
Why would they waste propellant on hovering after they did all that trouble of trying a high-g, 3 engine landing burn profile?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Lou744 on 06/17/2016 07:26 am
Maybe they attempted (unsuccessfully) to throttle the last Merlin to a lower thrust than we’ve been led to expect is possible…  Less of a slam- more of a hover?

What if they're trying to throttle below 40% to give it hover capability? 30-35%, depending on residuals?

Thought I had an original idea for my first post but not so.  Missed by 20 minutes...  :-X
 I still think this is a plausible explanation. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: NaN on 06/17/2016 07:58 am
The sequence of events, to me, looks like:

1. For some unknown reason, they reach hover almost a full stage height above the deck.  I can't see why this would be done on purpose.

2. The stage sits there for too long, burning up fuel as if it RP1 grew on trees.

3. The stage magically recovers, I am not sure how, but begins to descend again, all looks well.

4. As is evident in the stabilized video, the engine flames out just above the deck, and the stage falls down some 20 feet maybe?

5. It sits there for a second with a surprised look on its face, goes "ouch", and then slowly falls over, though appears (from the satellite picture) to have not exploded.

I would delete step 3. Looks to me like the stage killed most of its velocity too high and went to, and stayed at, minimum thrust on the center engine. Even at minimum thrust, it had already killed too much velocity to reach the ground and stayed in the near-hover until cutoff presumably due to the LOX depletion.
Engine cutoff is not instantaneous and thrust doesn't drop off instantly, nor does the flame disappear instantly, which is why it looked like there was a drop in thrust just before final cutoff. That's my guess.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Pete on 06/17/2016 08:37 am
The stage comes to a virtual standstill at some height above the deck, then descends again but at less than freefall.

This means the TWR at that time is < 1, but nonzero.

Question to the engine experts:
What happens in a merlin rocket engine if the LOX runs out, but you still have a rather large amount of pressurized gaseous O2 gushing through the plumbing?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: gadgetmind on 06/17/2016 08:41 am
Maybe a side engine was slow coming up to thrust, thrust vectoring on the others couldn't compensate, so they were too far off centre on an axis not visible in the video. Stage tried to fix it by slowing sooner, getting back central, and then reducing thrust to descend again. LOX runs out, game over.

Talk of fix by end of year suggests changes to things other than software, and ones they need to take care with as they don't want to jeopardise the ascent phase.

If this was anything like a quick fix Elon would have said "next week, maybe"!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: alexterrell on 06/17/2016 09:05 am
This strikes me as a control problem - as put above "it landed too high" - either:
- A faulty input sensor. How does the descent stage know it's altitude, especially as a laser range finder may be blocked by smoke?
- An error in the algorithm itself. This would have been run in simulations, but these may not capture all inputs.

The algorithm itself may rely on some form of sensor fusion - taking input from a range finder, GPS, radar, perhaps an external camera, inertial sensors, and then has to fuse these to come up with a true position.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/17/2016 09:08 am
Is it just me, or do we seem to have three different things going on here?  A problem with one engine failing to come up to thrust, achieving TW=0 above the deck (which shouldn't happen) and then a LOX depletion (maybe from coming to a hover above the deck and then running out of LOX because that was just the extra half-second of burn time the system didn't have left).

This sounds plausible. Also maybe the landing altimeter got toasted during entry and the stage tried to land 20 feet above deck level, then ran out of LOX waiting for a touchdown that never happened.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hrissan on 06/17/2016 09:33 am
Here's a stabilized version:

https://www.youtube.com/watch?v=p5_hvVbxAAo

From reddit here:

https://www.reddit.com/r/spacex/comments/4ogmvc/elon_musk_on_twitter_looks_like_early_liquid/d4chgzp
Here is an analysis of this video. Resolution is too low for good accuracy, but still, something interesting.

If adding quadratic trend line of seconds 5-9, it shows deceleration of ~1.1g which if continues would bring the stage to stop @ height of 30 meters around second 10.

But instead, the stage descends with almost constant velocity for next 6 seconds... Not good.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: vanoord on 06/17/2016 09:37 am
Have we seen this amount of dark smoke appearing so quickly at landing before?

From the onboard footage, one side of the stage was burning immediately after landing, worse than previously.

Are we probably looking at a hard landing that ruptured something to cause the fire; and a subsequent collapse of the stage caused either by damage to a leg?

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Ben the Space Brit on 06/17/2016 10:00 am
Elon Musk's initial Tweet was likely based on an early and immediate review of the initial telemetry plus a look at the wreckage on the deck of the Of Course I Still Love You. However, further analysis might change what they think caused this failure.

The smoke makes me wonder if one of the engines' fuel systems ruptured causing LOX and RP1 to mix on the hot surface of the hull or engines, causing it to ignite; reduced propellent pressure or even propellent starvation would have caused the affected engine to flame out inducing significant off-axis thrust for which the gimballed centre engine (if it was still functioning) would not have been able to compensate.

SpaceX's controllers would have seen the thrust drop-off from the affected engine as well as the indicators for a catastrophic LOX feed pressure drop but would not have any idea of the root cause because of the LOS from OCISLY at the critical moment.

I still think that Elon was talking about a secondary, possibly mechanical, braking system for terminal approach. However, I have the feeling that this is going to turn out to have either an engine or fuel system failure as a root cause.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/17/2016 10:01 am
Have we seen this amount of dark smoke appearing so quickly at landing before?

Don't think so, but it's consistent with the aft end of the stage being "accordioned", rupturing RP-1 feed lines and spewing burning RP-1.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Oersted on 06/17/2016 10:12 am
One thing is for sure: SpaceX will learn HUGE amounts from this near-miss. Both from the telemetry and from the wreckage. In that sense I am quite sure that this 'failure' will lead to a lot of 'saves' later on that will more than compensate for this loss.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Pete on 06/17/2016 10:27 am
Have we seen this amount of dark smoke appearing so quickly at landing before?

Don't think so, but it's consistent with the aft end of the stage being "accordioned", rupturing RP-1 feed lines and spewing burning RP-1.

Also consistent with an engine *trying* to run full speed, but with none or way too little LOX in the mix. If fuel pump is still active, it would be spewing about 100kg of unburnt RP-1 per second....
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Steven Pietrobon on 06/17/2016 10:31 am
Also consistent with an engine *trying* to run full speed, but with none or way too little LOX in the mix. If fuel pump is still active, it would be spewing about 100kg of unburnt RP-1 per second....

Yes, but without any LOX the gas generator would stop making gas which would stop the turbine which would stop any RP-1 from being pumped.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jarnis on 06/17/2016 10:44 am
Also consistent with an engine *trying* to run full speed, but with none or way too little LOX in the mix. If fuel pump is still active, it would be spewing about 100kg of unburnt RP-1 per second....

Yes, but without any LOX the gas generator would stop making gas which would stop the turbine which would stop any RP-1 from being pumped.

Wouldn't it take several seconds to spin down, which gives plenty of time to spill enough unburnt RP-1 to get the black smoke we saw?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cuddihy on 06/17/2016 11:13 am
Yes, there's a bit of energy in the spinning turbine. But the fuel valve should be shut at that point, so I would think you'd need another rupture somewhere...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jarnis on 06/17/2016 12:26 pm
Yes, there's a bit of energy in the spinning turbine. But the fuel valve should be shut at that point, so I would think you'd need another rupture somewhere...

Would it? If engine controller still is directing the engine to produce thrust because, well, we're not landed yet, if LOX then runs out, gas generator would slowly die out (and no more LOX would come from the tank) but RP-1 would still flow for a while until the spinning turbine stops.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/17/2016 12:32 pm
Yes, there's a bit of energy in the spinning turbine. But the fuel valve should be shut at that point, so I would think you'd need another rupture somewhere...

Would it? If engine controller still is directing the engine to produce thrust because, well, we're not landed yet, if LOX then runs out, gas generator would slowly die out (and no more LOX would come from the tank) but RP-1 would still flow for a while until the spinning turbine stops.


Yes, when an engine goes into depletion shutdown, it isn't because it is starved of propellant, it is because low level sensors in the feedlines sense empty tanks and start the shutdown sequence.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: LouScheffer on 06/17/2016 01:27 pm
Is it just me, or do we seem to have three different things going on here?  A problem with one engine failing to come up to thrust, achieving TW=0 above the deck (which shouldn't happen) and then a LOX depletion (maybe from coming to a hover above the deck and then running out of LOX because that was just the extra half-second of burn time the system didn't have left).
I think these can all potentially be explained by the response of the control system to an off-nominal thrust.

The control system presumably has goals for speed and altitude at a given time before landing.  For example, if you are doing a 1G hoverslam, at t-4 seconds you want to be at 80 meters, dropping at 40 m/s.  So you target the end of the 3 engine burn to reach these conditions.

Now suppose one engine starts slowly at some higher altitude.  Now the rocket is lower, and going faster, than it wants.  The controller will compensate, but perhaps due to throttle response limitations can only order a more-or-less uniform acceleration over the few remaining seconds.  However, these is no uniform acceleration that is perfect.  If it tries to reach the correct speed at t-4, it will be too low.  If it targets the correct altitude at t-4, it will need to apply a higher acceleration, which will leave it with too little vertical speed at t-4.  Now you are in trouble, since the stage can only sink so fast due to minimum throttle limits.  It runs out of propellent before landing.

So I think we can explain all the effects as follow-on from the initial lack of response, and a control system algorithm that prioritizes altitude over speed if it has to make a choice.  This also implies the control system is trying to stick to some pre-planned trajectory, or at least some pre-planned waypoints, rather than trying a to compute a complete solution from scratch at each moment.  Such an approach would be more difficult to design and test, but much more capable of handling off-nominal engine starts.  Perhaps this is the improvement that Musk has stated is due on later flights.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: eriblo on 06/17/2016 02:28 pm
The graphs of height and speed vs time sort of look like a standard landing when having some height uncertainty and adequate throttling: decelerate to reach a safe landing speed at a comfortable height, descent at constant speed and kill the engine when touch down is detected. Have enough propellant for the maximum likely extent of the constant decent phase ::)
Except the height error should be nowhere close to that large, that was likely not a good landing speed and they cant throttle that low as far as we know...

EDIT: Actually, looking at the stabilized video it looks like an initial height error of 30-40 m followed by a careful descent until running out of propellant at ~15 m and dropping like a rock. The other two points still stand...

[...]
So I think we can explain all the effects as follow-on from the initial lack of response, and a control system algorithm that prioritizes altitude over speed if it has to make a choice.  This also implies the control system is trying to stick to some pre-planned trajectory, or at least some pre-planned waypoints, rather than trying a to compute a complete solution from scratch at each moment.  Such an approach would be more difficult to design and test, but much more capable of handling off-nominal engine starts.  Perhaps this is the improvement that Musk has stated is due on later flights.
We know they are doing this for the ascent, do we have any reason to expect a different approach for landing?

Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 02:54 pm
Thinking about this a bit more, I wonder if SpaceX was trying a different landing profile in response to the previous hard landing and a cutting it too close to the margins.... Pushing the edge of the envelope and exceeding it...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: clongton on 06/17/2016 02:57 pm
The more I read of these posts the more convinced I am that all the smoke pre-touchdown was because RP-1 was still burning with ever decreasing LOX to support that burn. That's exactly what the exhaust of a diesel or kerosene engine looks like when it has too little air (oxidizer) to support the burn. It runs very fuel rich producing huge amounts of black smoke. In this scenario, Elon's tweet is correct wrt LOX depletion, and the posters above are also correct in that the RP-1 pumps continue to function until the gas generator actually winds down and stops - a non-zero time event. During that wind-down is when all the black smoke appears, the natural result of RP-1 continuing to burn with ever decreasing LOX to support it (LOX depletion is not an instantaneous event); hence lots of black smoke. Remember that the black smoke started *before* the anticipated hover-slam touchdown. It ran out of LOX while still descending.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: LouScheffer on 06/17/2016 03:21 pm
[...]
So I think we can explain all the effects as follow-on from the initial lack of response, and a control system algorithm that prioritizes altitude over speed if it has to make a choice.  This also implies the control system is trying to stick to some pre-planned trajectory, or at least some pre-planned waypoints, rather than trying a to compute a complete solution from scratch at each moment.  Such an approach would be more difficult to design and test, but much more capable of handling off-nominal engine starts.  Perhaps this is the improvement that Musk has stated is due on later flights.
We know they are doing this for the ascent, do we have any reason to expect a different approach for landing?
To be clear, this is speculation on my part on how the algorithm might work.  However,
(a) It explains the odd behavior we see on the video
(b) It is consistent with both of Musk's statements.  The direct cause of the crash was running out of LOX, but the root cause was a slow start of one of the engines.

Also, computing a trajectory for landing is a much more complex problem than computing an ascent trajectory.  There is the 1-3-1 engine sequence, which involves calculating a thrust vs time for all segments, plus optimum times to transition.  Gimbal commanding may be different in each regime (it appears the other engines have less room to gimbal), and certainly the gains of the control loops vary.  The mass and center-of-gravity are changing very quickly, compared to the end of the first stage burn where the mass of the second stage dominates.  There are also gas thrusters, and grid fins to command (and the grid fins are dropping in influence as the rocket slows), so there is no unique solution.  Both the minimum and maximum engine forces are limited, making it a 2-sided non-linear control problem.

Because of all these complexities, I would not be surprised if they have worked out an optimum solution in advance, then ask the rocket to stick to it.  Much simpler control loops in the rocket, but with the disadvantage we just saw - some failures that are in theory recoverable cannot be recovered if you stick with the original trajectory.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/17/2016 03:59 pm
This is just representative, it is an RS-68.  But once the low level sensors activate, the gas generator valves and then the main prop valves would close.  And it would be like an nominal shutdown.  That is the reason for the low level sensors, to prevent the engine from seeing empty lines.  Which, BTW, would lead to turbine overspeed and the engine coming apart.    There is some finite time for the engine to shut down, but that is taken into consideration of the sensors and the timing of the shutdown command. 

but in all, there isn't going to be an engine just pumping out RP-1 from lack of Ox.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/17/2016 04:08 pm
I think we need to differentiate between LOX quantity vs LOX flow IMHO...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: iamlucky13 on 06/17/2016 08:59 pm
While acknowledging Jim's point about controlled shutdowns, I wonder if SpaceX might have chosen to override the low fuel shut-down for the landing phase. They know they're marginal on fuel and may figure a turbo-pump coming apart violently is less destructive to the stage than dropping it on the barge. When they're so close, a second or two more thrust might be enough.

It's one thing to risk turbopump failure going uphill with your customer's payload still attached - shrapnel could damage the second stage or payload, or the uncontrolled change in angular momentum put you in a dangerous orientation for separation and second stage ignition. It's another when the worst case no longer involves the payload, and is trading off the risk of fuel starvation and crashing the 1st stage with the risk of turbopump failure and crashing the 1st stage.

Whether SpaceX did so is entirely speculation on my part, but the fact that they initially thought one engine underperformed strikes me as more consistent with starvation than controlled shutdown, which I'd think would have been indicated clearly in their telemetry, and been fairly consistent between engines.

If so, in addition to the momentum of the turbo-pump continuing to push fuel into the nozzle for a few seconds, if there was LOX sloshing or reduced tank repressurization reducing the rate the last traces of LOX enter the pump and then continue to the gas generator and subsequently the pumps, I could envision the last couple of seconds still seeing reduced power out of the turbopump even though the mix has turned very rich. It doesn't take much fuel to produce a lot of smoke, and the normal rate is somewhere in the range of 300 pounds per second.

Further, that smoke moved fast - about 3 seconds to reach the height of the stage, and it expanded almost as much out as it did up. For that reason also I'm tending to think it was being burned under pressure - meaning in the chamber, not on the deck. I'm not used to seeing the plume from a spilled kerosene fire expanding so rapidly, or since driven by buoyancy, being so broad. For example:
https://www.youtube.com/watch?v=sELqeeVNizw
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/18/2016 12:26 am
While acknowledging Jim's point about controlled shutdowns, I wonder if SpaceX might have chosen to override the low fuel shut-down for the landing phase. They know they're marginal on fuel and may figure a turbo-pump coming apart violently is less destructive to the stage than dropping it on the barge. When they're so close, a second or two more thrust might be enough.

It's one thing to risk turbopump failure going uphill with your customer's payload still attached - shrapnel could damage the second stage or payload, or the uncontrolled change in angular momentum put you in a dangerous orientation for separation and second stage ignition. It's another when the worst case no longer involves the payload, and is trading off the risk of fuel starvation and crashing the 1st stage with the risk of turbopump failure and crashing the 1st stage.

Whether SpaceX did so is entirely speculation on my part, but the fact that they initially thought one engine underperformed strikes me as more consistent with starvation than controlled shutdown, which I'd think would have been indicated clearly in their telemetry, and been fairly consistent between engines.

If so, in addition to the momentum of the turbo-pump continuing to push fuel into the nozzle for a few seconds, if there was LOX sloshing or reduced tank repressurization reducing the rate the last traces of LOX enter the pump and then continue to the gas generator and subsequently the pumps, I could envision the last couple of seconds still seeing reduced power out of the turbopump even though the mix has turned very rich. It doesn't take much fuel to produce a lot of smoke, and the normal rate is somewhere in the range of 300 pounds per second.

Further, that smoke moved fast - about 3 seconds to reach the height of the stage, and it expanded almost as much out as it did up. For that reason also I'm tending to think it was being burned under pressure - meaning in the chamber, not on the deck. I'm not used to seeing the plume from a spilled kerosene fire expanding so rapidly, or since driven by buoyancy, being so broad. For example:
https://www.youtube.com/watch?v=sELqeeVNizw

I think so too.  On descent, what are you going to do?  Shut down gracefully 20' above the deck?

We don't know if SpaceX implemented this but it's not an unheard of practice:

I remembered talk of this after the A320 double-engine bird strike in NY (The Hudson landing)

Turned out both engine controllers shut down because of excessive vibrations (to protect the engine), but once the first one did, it probably made more sense to keep the other one running in spite of being sick.  I don't know if it ever got reduced to practice though..
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Grandpa to Two on 06/18/2016 12:57 am
I've watched the stabilized video dozens of times. I don't see any smoke prior to a hard touchdown. At that point the rocket flame stops and then the black smoke starts. This leads me
The more I read of these posts the more convinced I am that all the smoke pre-touchdown was because RP-1 was still burning with ever decreasing LOX to support that burn. That's exactly what the exhaust of a diesel or kerosene engine looks like when it has too little air (oxidizer) to support the burn. It runs very fuel rich producing huge amounts of black smoke. In this scenario, Elon's tweet is correct wrt LOX depletion, and the posters above are also correct in that the RP-1 pumps continue to function until the gas generator actually winds down and stops - a non-zero time event. During that wind-down is when all the black smoke appears, the natural result of RP-1 continuing to burn with ever decreasing LOX to support it (LOX depletion is not an instantaneous event); hence lots of black smoke. Remember that the black smoke started *before* the anticipated hover-slam touchdown. It ran out of LOX while still descending.
to believe that Steve
Also consistent with an engine *trying* to run full speed, but with none or way too little LOX in the mix. If fuel pump is still active, it would be spewing about 100kg of unburnt RP-1 per second....

Yes, but without any LOX the gas generator would stop making gas which would stop the turbine which would stop any RP-1 from being pumped.
is correct. Hard landing impacts the nozzles crushing them and driving the rocket engines upward, severing RP1 lines or possibly the tank itself. That could explain the pressure behind the smokes sudden expansion.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Michael Baylor on 06/18/2016 01:08 am
I am going to guess that after the fast landing in the Thaicom-8 mission, where the Falcon 9 nearly tipped over, SpaceX made changes in an attempt to reduce the speed. As others have mentioned, F9 seemed to hover more than usual before landing. This was because SpaceX may have been experimenting with a slightly different burn sequence in an attempt to reduce the speed more than last time. It is possible that this experiment took up too much LOX which is why this time it ran out, unlike the last two GTO missions. As a result of this miscalculation, the F9 lost thrust and hit the deck a little faster the Thaicom-8. Unfortunately, this time there was not enough aluminum honeycomb to save F9.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: SLC on 06/18/2016 01:28 am
Isn't it possible that during the few seconds of apparent "hovering", the stage was in fact leaning towards or away from the camera, and was busy making a necessary adjustment to its horizontal position towards or away from the camera?   Without a second camera angle we can't be sure.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Okie_Steve on 06/18/2016 02:40 am
Year of experiments. When you aim for the edge of the envelope some times you are in and some times you are out and it goes Foom!
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Torbjorn Larsson, OM on 06/18/2016 05:23 am
We have a CRUD [Clouded Rapid Unscheduled Disassembly].

I do hope SpaceX will learn from this. Musk's tweets implies this may be so, when the fog clears.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: deruch on 06/18/2016 06:45 am
Year of experiments. When you aim for the edge of the envelope some times you are in and some times you are out and it goes Foom!

Gwynne Shotwell's philosophy on test programs (originally in relation to Grasshopper):
Quote from: Gwynne Shotwell to Popular Mechanics
The tests are going beautifully, which fundamentally means we're not pushing the envelope hard enough.  We should have some failures… We need to push harder.

With all due respect to Grasshopper and F9R-dev1, I think these tests are harder.  So, not too surprising if there turn out to be a few more failures along the way.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: [email protected] on 06/18/2016 08:22 am
Maybe they recovered more stages that they thought, so they pushed a bit more
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: vanoord on 06/18/2016 09:17 am
Hard landing impacts the nozzles crushing them and driving the rocket engines upward, severing RP1 lines or possibly the tank itself. That could explain the pressure behind the smokes sudden expansion.

It *looked* as if the stage was sat on its legs immediately after landing, albeit only the outline of the left hand (as looking at it) leg was visible - the angles of the leg and the support looked broadly as they should have; and the stage seemed to be far enough off the deck for the nozzles not to have touched the deck.

I might suggest that a hard landing caused RP1 line(s) to rupture on impact, causing rapid spillage and the resultant fires. As for the collapse of the stage, the candidates would be either failure of the structure of the stage or a leg collapsing - which is consistent with previous experience.

It may become clearer what happened when the ASDS gets back to port (later today?) - the Deimos image *suggests* that there might be a lot of debris onboard, which should give more information.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Pete on 06/18/2016 09:36 am
My question is still this:
The general consensus is that there is *no way* for the landing stage to have a TWR < 1, even with just one engine running at maximum downthrottle.

Yet the video of the landing clearly shows the stage slowing down to almost a standstill, and then *increase* it's descent rate. Does this not require a TWR < 1 ?

From this I reason that the engine could *not* have been functioning normally, in those last 5 seconds before impact.
And equally, could not have been actually shut down, as neither the rate of descent nor the flame appearance matched a shutdown engine. Previous landing show engine shutdown time of << 1 second.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: andy_l on 06/18/2016 10:52 am

It may become clearer what happened when the ASDS gets back to port (later today?) - the Deimos image *suggests* that there might be a lot of debris onboard, which should give more information.

Which image are you referring to?

Cheers,


Andy
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Zpoxy on 06/18/2016 11:09 am
Look here:

https://twitter.com/deimosimaging/status/743153542362439680
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: LouScheffer on 06/18/2016 11:31 am
My question is still this:
The general consensus is that there is *no way* for the landing stage to have a TWR < 1, even with just one engine running at maximum downthrottle.

Yet the video of the landing clearly shows the stage slowing down to almost a standstill, and then *increase* it's descent rate. Does this not require a TWR < 1 ?

From this I reason that the engine could *not* have been functioning normally, in those last 5 seconds before impact.
And equally, could not have been actually shut down, as neither the rate of descent nor the flame appearance matched a shutdown engine. Previous landing show engine shutdown time of << 1 second.
From  this plot  (http://forum.nasaspaceflight.com/index.php?topic=40088.msg1550704#msg1550704) it looks like it never achieved hover, but did achieve constant vertical velocity (T/W = 1).

I've always wondered if they have different throttling limits for different situations.  For example (with made up numbers) maybe the normal lower limit is 40%.  But perhaps 30% is possible, but may damage the engine, and below 30% the engine simply does not work.

So in this case, perhaps the controller found itself in a situation where the normal minimum (40%) would bring it to a stop, then reverse, about 30 meters above the deck. (perhaps  due to needed extra acceleration at intermediate times, to correct for insufficient acceleration at the start (http://forum.nasaspaceflight.com/index.php?topic=40088.msg1550752#msg1550752), due to slow startup of one engine).  So now the controller reduces thrust to the emergency minimum of 30%, perhaps sacrificing the center engine in hopes of saving the stage.  This gives T/W=1, the rocket keeps (slowly) sinking, but runs out of fuel.  The controller cannot expedite the landing any more, so it does the best it can at the risk of running out of fuel.

Again, this is all speculation, but explains the shape of the graphs above.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: guckyfan on 06/18/2016 12:19 pm
it looks like it never achieved hover, but did achieve constant vertical velocity (T/W = 1).


Which is not hovering but means it is capable of hover.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: speedevil on 06/18/2016 01:54 pm
My question is still this:
The general consensus is that there is *no way* for the landing stage to have a TWR < 1, even with just one engine running at maximum downthrottle.

Yet the video of the landing clearly shows the stage slowing down to almost a standstill, and then *increase* it's descent rate. Does this not require a TWR < 1 ?

Initial engine failure on one of the side engines causes large position error towards or away from the barge from the perspective of the camera.
Control system senses it's going to miss the barge, and gimbals and possibly tilts the stage over to get as much horizontal authority as it can, followed by recovering, but running out of fuel before velocity is nulled.
?
We're not seeing a gradual hover, but the stage coming in hard sideways at a large decelleration.

Is the observed maximum tilt (towards or away from the camera) enough to add up to not requiring a lower than nominal thrust, taking into account maximum plausible horizontal tilt + gimbal?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: philw1776 on 06/18/2016 02:01 pm
Year of experiments. When you aim for the edge of the envelope some times you are in and some times you are out and it goes Foom!

Gwynne Shotwell's philosophy on test programs (originally in relation to Grasshopper):
Quote from: Gwynne Shotwell to Popular Mechanics
The tests are going beautifully, which fundamentally means we're not pushing the envelope hard enough.  We should have some failures… We need to push harder.

With all due respect to Grasshopper and F9R-dev1, I think these tests are harder.  So, not too surprising if there turn out to be a few more failures along the way.

Yes.  Given that Musk also publicly stated he expected a ~70% success rate, failures during this test the limits stage are expected.  Otherwise how do you know the payload/energy true limits outside of calculated models that we know contain certain assumptions.

I don't think that the booster design is yet re-fly reliably ready so this is the perfect time to RUD a few yet to be optimized 1st stages to perfect the long term higher flight rate re-use capability.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/18/2016 02:13 pm
I just don't see how it can even approach a TWR of 1.

Merlin 1D sea-level thrust: 845 kN
Merlin 1D minimum throttle: 55%
First stage dry weight: 22 tonnes
(source: spaceflight 101 (http://spaceflight101.com/spacerockets/falcon-9-ft/))

Assuming 3 tonnes of propellants at start of landing burn, at 55% throttle a single Merlin 1D engine provides 465 kN of thrust, and for a total mass of 25 tonnes that's a TWR of 1.88.

Even considering off-vertical thrust, at an extreme 45° angle the vertical component (465 kN * cos(45°) = 328 kN) would still result in a TWR of 1.3.

And I'm completely ignoring air drag here, which can be thought as reducing the effective weight of the stage, thus increasing TWR further.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: MikeAtkinson on 06/18/2016 02:27 pm
I just don't see how it can even approach a TWR of 1.

Merlin 1D sea-level thrust: 845 kN
Merlin 1D minimum throttle: 55%
First stage dry weight: 22 tonnes
(source: spaceflight 101 (http://spaceflight101.com/spacerockets/falcon-9-ft/))

Assuming 3 tonnes of propellants at start of landing burn, at 55% throttle a single Merlin 1D engine provides 465 kN of thrust, and for a total mass of 25 tonnes that's a TWR of 1.88.

Even considering off-vertical thrust, at an extreme 45° angle the vertical component (465 kN * cos(45°) = 328 kN) would still result in a TWR of 1.3.

And I'm completely ignoring air drag here, which can be thought as reducing the effective weight of the stage, thus increasing TWR further.

We think the Merlin 1D (full thrust) now has a minimum throttle of about 40%, it could even be as low as 30%. Given the choice of lowering thrust below the Merlin 1D's rated minimum and not being able to land, it is quite possible that the guidance/code software has code to lower the Merlin 1D thrust.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: the_other_Doug on 06/18/2016 03:37 pm
Or the stage was coming to a zero sink rate 30 meters above the deck, LOX depletion occurred, and the remaining descent was slowed only by air resistance and the thrust generated by the engine tail-off.  As has been pointed out many times, these engines don't just go to zero thrust instantaneously.

I believe that's more likely than a magical, hidden, never-before-mentioned ability to actually throttle deeper than we have been told the engine is capable of throttling...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: LouScheffer on 06/18/2016 04:26 pm
I've always wondered if they have different throttling limits for different situations.  For example (with made up numbers) maybe the normal lower limit is 40%.  But perhaps 30% is possible, but may damage the engine, and below 30% the engine simply does not work.

From the NASA document Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090037061.pdf) typical problems with throtttling too low are combustion and system instabilities, performance degradation, excessive heat transfer, and pump dynamics.  The pump problems, in turn, typically involve rotordynamic stability: running at shaft critical speeds, thrust bearing lift off, pump stall, boost pump bi-stability, and pump performance.

Most of these problems, in experiments, did not result in immediate engine failure.  The engines could be run well below their normal lower limit, though the instabilities often resulted in damage and the engines would have eventually failed.  The SSME (Space Shuttle Main Engine), for example, was rated down to 65% throttle, but would actually work down to 17%, though with lots of worries about the pumps.

For SpaceX, however, if the choice is running below the lower limit or losing the stage, surely it would be better to overstress the center engine in the hopes of saving everything else.  The center engine would then require a detailed inspection, or maybe even replacement, but that's still a big improvement over losing the whole stage.  So I would not be surprised if the SpaceX software will throttle below the lower limit if that's the only way to land.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: wannamoonbase on 06/18/2016 04:41 pm
Year of experiments. When you aim for the edge of the envelope some times you are in and some times you are out and it goes Foom!

Gwynne Shotwell's philosophy on test programs (originally in relation to Grasshopper):
Quote from: Gwynne Shotwell to Popular Mechanics
The tests are going beautifully, which fundamentally means we're not pushing the envelope hard enough.  We should have some failures… We need to push harder.

With all due respect to Grasshopper and F9R-dev1, I think these tests are harder.  So, not too surprising if there turn out to be a few more failures along the way.

Yes.  Given that Musk also publicly stated he expected a ~70% success rate, failures during this test the limits stage are expected.  Otherwise how do you know the payload/energy true limits outside of calculated models that we know contain certain assumptions.

I don't think that the booster design is yet re-fly reliably ready so this is the perfect time to RUD a few yet to be optimized 1st stages to perfect the long term higher flight rate re-use capability.

Agreed.  These GTO boosters are coming back toasted and despite some statements they don't seem readily re-fly able.  The LEO stages appear less abused and ready to rock and roll.

Until the F9 Fuller Thrust and design changes to improve condition I think SpaceX is wise to push the envelop and attempt things they may not want to on a recoverable vehicle in say 6-12 months.

I just try to keep things in perspective to that first grainy F9 landing video.  That wasn't too long ago and now they are landing and recovering stages.  2 years from now, who knows.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/18/2016 06:40 pm
I've always wondered if they have different throttling limits for different situations.  For example (with made up numbers) maybe the normal lower limit is 40%.  But perhaps 30% is possible, but may damage the engine, and below 30% the engine simply does not work.

From the NASA document Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090037061.pdf) typical problems with throtttling too low are combustion and system instabilities, performance degradation, excessive heat transfer, and pump dynamics.  The pump problems, in turn, typically involve rotordynamic stability: running at shaft critical speeds, thrust bearing lift off, pump stall, boost pump bi-stability, and pump performance.

Most of these problems, in experiments, did not result in immediate engine failure.  The engines could be run well below their normal lower limit, though the instabilities often resulted in damage and the engines would have eventually failed.  The SSME (Space Shuttle Main Engine), for example, was rated down to 65% throttle, but would actually work down to 17%, though with lots of worries about the pumps.

For SpaceX, however, if the choice is running below the lower limit or losing the stage, surely it would be better to overstress the center engine in the hopes of saving everything else.  The center engine would then require a detailed inspection, or maybe even replacement, but that's still a big improvement over losing the whole stage.  So I would not be surprised if the SpaceX software will throttle below the lower limit if that's the only way to land.

Exactly.  It's do or die, so you throttle down to whatever you need to, no questions asked.
And same with propellant depletion.  Even if it's sucking in He bubbles, what are you going to do - park and refuel?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: andy_l on 06/18/2016 08:16 pm
Look here:

https://twitter.com/deimosimaging/status/743153542362439680

Thanks. I'd seen a number of references to a satellite image but hadn't managed to find it.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cscott on 06/18/2016 08:59 pm
I've always wondered if they have different throttling limits for different situations.  For example (with made up numbers) maybe the normal lower limit is 40%.  But perhaps 30% is possible, but may damage the engine, and below 30% the engine simply does not work.

From the NASA document Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090037061.pdf) typical problems with throtttling too low are combustion and system instabilities, performance degradation, excessive heat transfer, and pump dynamics.  The pump problems, in turn, typically involve rotordynamic stability: running at shaft critical speeds, thrust bearing lift off, pump stall, boost pump bi-stability, and pump performance.

Most of these problems, in experiments, did not result in immediate engine failure.  The engines could be run well below their normal lower limit, though the instabilities often resulted in damage and the engines would have eventually failed.  The SSME (Space Shuttle Main Engine), for example, was rated down to 65% throttle, but would actually work down to 17%, though with lots of worries about the pumps.

For SpaceX, however, if the choice is running below the lower limit or losing the stage, surely it would be better to overstress the center engine in the hopes of saving everything else.  The center engine would then require a detailed inspection, or maybe even replacement, but that's still a big improvement over losing the whole stage.  So I would not be surprised if the SpaceX software will throttle below the lower limit if that's the only way to land.
If you're correct, why did the stage hover and crash?

It was because the engines couldn't throttle low enough to maintain a decent sink rate.

I don't think your argument matches the evidence.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Dante80 on 06/18/2016 09:14 pm
I just don't see how it can even approach a TWR of 1.

Merlin 1D sea-level thrust: 845 kN
Merlin 1D minimum throttle: 55%
First stage dry weight: 22 tonnes
(source: spaceflight 101 (http://spaceflight101.com/spacerockets/falcon-9-ft/))

Assuming 3 tonnes of propellants at start of landing burn, at 55% throttle a single Merlin 1D engine provides 465 kN of thrust, and for a total mass of 25 tonnes that's a TWR of 1.88.

Even considering off-vertical thrust, at an extreme 45° angle the vertical component (465 kN * cos(45°) = 328 kN) would still result in a TWR of 1.3.

And I'm completely ignoring air drag here, which can be thought as reducing the effective weight of the stage, thus increasing TWR further.

I believe that's more likely than a magical, hidden, never-before-mentioned ability to actually throttle deeper than we have been told the engine is capable of throttling...

We already know that M9 can go down to (not by, to) 40% reliably.
https://twitter.com/elonmusk/status/728753234811060224 (https://twitter.com/elonmusk/status/728753234811060224)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meithan on 06/18/2016 10:18 pm
We think the Merlin 1D (full thrust) now has a minimum throttle of about 40%, it could even be as low as 30%. Given the choice of lowering thrust below the Merlin 1D's rated minimum and not being able to land, it is quite possible that the guidance/code software has code to lower the Merlin 1D thrust.

Uhm, it's possible, but I haven't seen anything official-ish suggesting that's happening. You'd have to be able to throttle below 30% for TWR to be below 1.

But as someone said before, the strategy should be to master high-g landings since they're efficient propellant-wise, not give Falcon 9 the ability to hover. I'm not convinced by the "last resort" argument of such ability, but it's possible.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: John Alan on 06/18/2016 11:23 pm
Just to point out another advantage a lower available throttle setting for the M1D will provide...   ???

The core stage 9 engines on a FH...  :o

There is much to gain in throw weight if you can throttle those way back between say Max Q and Booster cutoff...
Then go back to max thrust with only G forces as you limiting item to watch, till MECO...
That acts just like cross-feed... but without the weight, complexity, and headache...  8)

I summary... there are TWO reasons SpaceX is likely working on a deeper throttle range...
ASDS landings AND FH core usage...

And being a pintle injector engine design...
My guess is the gas turbine in the turbo pump may be the area that things go wrong at low-low power settings...
Not optimized to go that slow and stalls out...
Remember a turboshaft engine at idle is sucking fuel like mad because it's also driving an air compressor...  :o
No such thing on a gas generator rocket engine... to 'load up" the power turbine above it's stall speeds and flows...
The moving pintle inside helps, by adding some back pressure to the prop flow and loading up the pump a bit..
But then at high throttle you got too much back pressure for the pump to overcome...
IF they could change the spring rate on that pintle on the fly... THEN...  :o
In hydraulic psi relief valves... there are ways to make that adjustable on the fly via a hydraulic or air override...
The pintle kinda serves that function as I understand it... sets back pressure to the pump... Hmmm...  :-\
Just my hand waving, Hydraulics and what I know about pumps... for what it's worth opinion...  ;)

The advantage of the deep throttle idea was covered in the past in FH threads... search for it if you want...
Just pointing that out, in case some here have missed that connection of need...  ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: speedevil on 06/19/2016 12:53 am
Just to point out another advantage a lower available throttle setting for the M1D will provide...   ???

The core stage 9 engines on a FH...  :o

There is much to gain in throw weight if you can throttle those way back between say Max Q and Booster cutoff...
Then go back to max thrust with only G forces as you limiting item to watch, till MECO...
That acts just like cross-feed... but without the weight, complexity, and headache...  8)

In principle, if you're confident enough on relights, you can put out the middle three engines too. In-flight restarts are another nice thing to learn.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Barmaglot on 06/19/2016 02:23 am
There is much to gain in throw weight if you can throttle those way back between say Max Q and Booster cutoff...
Then go back to max thrust with only G forces as you limiting item to watch, till MECO...
That acts just like cross-feed... but without the weight, complexity, and headache...  8)

Throttling the center would provide some benefits of cross-feed, but not all of them. With cross-feed, side boosters would consume their fuel 50% faster, which means they would stage at significantly lower velocity, which, simultaneously, would reduce the energy spent by the rocket on accelerating their structural mass, reduce energy required to decelerate them (which would directly translate into increased fraction of fuel spent on accelerating the payload) and leave the center fully fueled at booster separation, which would allow it to reserve a higher fuel fraction for deceleration and recovery after second stage separation.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Craftyatom on 06/19/2016 06:17 am
Just to point out another advantage a lower available throttle setting for the M1D will provide...   ???

The core stage 9 engines on a FH...  :o

There is much to gain in throw weight if you can throttle those way back between say Max Q and Booster cutoff...
Then go back to max thrust with only G forces as you limiting item to watch, till MECO...
That acts just like cross-feed... but without the weight, complexity, and headache...  8)

In principle, if you're confident enough on relights, you can put out the middle three engines too. In-flight restarts are another nice thing to learn.

Before anyone goes so far as to shut down engines and then re-start them later on in the flight, I think they'd pull a Titan and just not start the engines until further on in the ascent profile.  Sure, it increases gravity losses, but somehow I don't see the trade-off between the performance gain and safety going well.

Anyways, FH has plenty of performance margin at the moment for a number of payloads, and I don't think we'd see anyone agree to any of these "crazy" profiles just to lift their slightly-too-heavy bird.  All the same, I don't think SpaceX would try to get any "crazy" low throttle percentages with a payload on board.  It's likely that throttle capability will only benefit landing on the F9.

That said, it may help greatly with SpaceX's future developments.  We know they've got big plans for engines, and the more they learn about engine dynamics in unique and interesting situations, the better.  But that much has been said before.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: LouScheffer on 06/19/2016 12:56 pm
For SpaceX, however, if the choice is running below the lower limit or losing the stage, surely it would be better to overstress the center engine in the hopes of saving everything else.  The center engine would then require a detailed inspection, or maybe even replacement, but that's still a big improvement over losing the whole stage.  So I would not be surprised if the SpaceX software will throttle below the lower limit if that's the only way to land.
If you're correct, why did the stage hover and crash?

It was because the engines couldn't throttle low enough to maintain a decent sink rate.

I don't think your argument matches the evidence.
This is a good point.  My suspicion is that the software is not sophisticated enough to do the right thing in an off-nominal situation.

Assume the engine is rated to throttle between 40-100% (actual numbers unimportant).  Then the landing, and the trajectory, will be designed to keep the throttle always in this range.  Going outside this range would mean using the engine in a regime it's not spec'ed for, meaning at least a detailed inspection and perhaps a replacement.  Since SpaceX wants minimal refurbishement,  I'd guess the initial landing software will try hard to stay within these limits.

Now in the off-nominal case that occurred (slow start on one engine) the software should in theory realize that the original plan is now fatally flawed, and create a new plan, running out of limits on the center engine, if need be. But that's a lot more complex.

So as a software developer, I'm guessing they made the software good enough to handle the expected range of variations.  After the slow start of one engine, it kept trying to converge to the original plan, not realizing it was doomed to failure.  When it reached 100 meters up, going down too slowly, it simply reduced the thrust to the programmed minimum.  What is should have done is said "Holy ****", I'm going to run out of fuel before I hit, ignore those engine limits, and let me drop.  I'll sacrifice the center engine if need be.  But software to correctly handle off-nominal conditions is MUCH more complex, both in development and testing, particularly since there is an almost inexhaustible number of possible conditions.

So I'm guessing what we are seeing is a side effect of software that (in this version) could not correctly handle this case.  Better software, at least for the "slow-start" case, will likely be the fix that Musk spoke of.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CorvusCorax on 06/19/2016 08:24 pm
I have written controllers ( model aircraft, aka hobby UAV ) the most important lesson that keeps teaching itself is KISS. Don't make the controller any more complex than it needs to be.

SpaceX adheres to that. That cost the CRS-7 dragon - although a contingency routine in the software could have saved it. Such a contingency routine is additional risk ( could get triggered by accident if you combine a faulty sensor with an unlucky chain of events) and you don't want overly smart on board software deploy chutes just before Max-Q.

As such its very very unlikely they would have any logic in there that says " things went ooopsies, go to plan C: now the engines can be throttled beyond design ratings"

Because diagnosing the oopsies in the first place is very hard. Usually oopsies happen because either sensors or actuators behave outof spec. But then chances are, either your state estimation is unreliable, or your controller output will have "undefined" effects, both of which is very hard to handle. You can throw heuristics at it, classificators, even neural nets...
None of them are compatible with KISS.

SpaceX controllers are going to be complicated as hell already, since theres so many mode changes that affect the model. Leg deployment, engine starts and shutdowns, changes in weight and COG...

To keep this controllable ( the control system from a predictability pov), you need the simplest possible solution that gets the job done.

So I'd guess the lower and upper throttle limits are hard, and clipping, even if the controller wants a setting beyond the min/max

Same with engine gimbals or other actuator limits.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: douglas100 on 06/19/2016 09:11 pm
I suppose it depends on the root cause of the crash. If it was basically down to pushing the envelope too far, then they've learned some valuable lessons. The solution, then, would be not to approach that edge on future flights. If the slow start of the engine was hardware related then there might be some small engineering mods which would fix it. Rather than making software changes to override a hardware problem, it seems sensible to deal with the root cause. I agree with CorvusCorax: you simply can't expect the software to deal with every possible contingency.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: hrissan on 06/19/2016 10:43 pm
The stage is descending with constant velocity for several seconds, so either Merlin throttles below 40% or the S1 landing weight is more than was estimated here... Or both, in any proportion.

A lucky soul might ask Elon in Twitter...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/20/2016 12:58 pm
Something to talk about... ;)

https://www.youtube.com/watch?v=_FdS4osHmn4
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: John Alan on 06/20/2016 01:31 pm
Question that has bugged me all night...  :-\

Where are the legs???   ???

Must of burned up in the post crash RP-1 fire...  :o

Need a crane to remove them otherwise... which they would not mess with at sea...  ???
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kevin-rf on 06/20/2016 03:11 pm
Aren't the legs carbon fiber? That can burn...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/20/2016 03:32 pm
Question that has bugged me all night...  :-\

Where are the legs???   ???

Must of burned up in the post crash RP-1 fire...  :o

Need a crane to remove them otherwise... which they would not mess with at sea...  ???
I see two legs items underneath, one under octoweb another under the flattened tank and what looks like one actuator, piston)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: macpacheco on 06/20/2016 04:32 pm
Aren't the legs carbon fiber? That can burn...
All areas that could catch fire during re-entry/landing is covered by a layer of SPAM (SpaceX Proprietary Ablative Material).
SPAM is designed to slowly combust when it gets very hot, its also good thermal insulator. Technically it isn't even a fire, as SPAM burns only as long as its very hot.
This has been discussed ad nauseum in other threads. Please google it.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/20/2016 05:48 pm
Aren't the legs carbon fiber? That can burn...
All areas that could catch fire during re-entry/landing is covered by a layer of SPAM (SpaceX Proprietary Ablative Material).


a.  Legs are not covered with SPAM
b.  What "could catch fire during re-entry/landing" doesn't matter when there is released propellant
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Doesitfloat on 06/20/2016 08:58 pm
Aren't the legs carbon fiber? That can burn...

Sort of
The fiber filaments don't burn. They are just carbon. The resin holding it together can burn. In addition resin can get hot and lose it's mechanical properties reverting back into liquid. IRRC the term for this is "Onset of Tg". Or in my terms the temperature where your carbon fiber part turns back into goo.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: kdhilliard on 06/20/2016 10:00 pm
Also, this was the first launch I noticed that there seemed to be some sort of liquid running from the hold downs.  I'm guessing this was water and was meant to help protect them against damage from exhaust impingement but if so it was running well before ignition.

That flow through the hold downs is first visible in the Technical broadcast at T-9:40, a few seconds after the "M-1D Chill Down" call.  I suspect that it is intended to prevent the hold downs from freezing up.

~Kirk
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/20/2016 10:05 pm
Aren't the legs carbon fiber? That can burn...

Sort of
The fiber filaments don't burn. They are just carbon. The resin holding it together can burn. In addition resin can get hot and lose it's mechanical properties reverting back into liquid. IRRC the term for this is "Onset of Tg". Or in my terms the temperature where your carbon fiber part turns back into goo.

That would be true of Fiberglass.  Carbon will burn just fine.   Whether that happens before or after the resin fails, I don't know.

The failure of the resin, btw, is not a "turn back into liquid" - that would be true of a thermoplastic material, which has a Tg (glass transition) temperature.  A two-part resin will generally just fail.  Burn, decompose, etc.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: speedevil on 06/20/2016 10:23 pm
The failure of the resin, btw, is not a "turn back into liquid" - that would be true of a thermoplastic material, which has a Tg (glass transition) temperature.  A two-part resin will generally just fail.  Burn, decompose, etc.
Epoxy resin does not fully cure all the way.
It will cure to some point, and be solid under the glass transition temperature.
If it later exceeds the Tg, it can go significantly more flexible and gel-like, not solid-like, and cure more.

This can be in some cases going along with decomposition, but it depends how high the Tg is.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/20/2016 10:49 pm
FYI...
https://www.youtube.com/watch?v=w608hwWqRQI
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/20/2016 11:04 pm
FYI...
https://www.youtube.com/watch?v=w608hwWqRQI

Wow - lovely - I wouldn't have imagined.  What resin is that?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: CorvusCorax on 06/20/2016 11:09 pm
Why are the legs gone?

To answer that, we could go back in time, to May 6, 1937, Lakehurst, New Jersey.

The largest air ship ever built, the LZ129 Hindenburg - a flying Titanic, a luxury liner in the sky, marvel of an era, and kept aloft by highly flammable hydrogen -  caught fire during landing approach after a catastrophic series of events (too harsh control manoeuvres cause wires to rip - whip-slashing through the structure, damaging hydrogen cells, hydrogen accumulates under the skin, slowly diffusing through the seams while reaching explosive concentrations within - all under thunderstormy high V/m atmospheric conditions, then as the anchor cable gets lowered, there's a discharge spark --> BOOM )

The ship turned into a giant fireball in midair and crashed. But the majority of the hydrogen deflagrated in less than half a minute.

Two thirds of the people on board actually survived the crash. One third died, mostly from burns. But what killed them wasn't the hydrogen deflagration but the also burning diesel fuel that was spilled and set ablaze in the crash, while trapped in the debris. Not unlike what kills people in contemporary airline crashes. And that diesel kept burning for several hours.

The same would have happened here. We have lot's of RP-1 spilled, but no oxidizer but air. So instead of a quick RUD, we have hundreds of liters spilled on deck, pooling around the debris, and burning continuously. Applying localized heat for possibly a long duration. (The drone ship has fire suppression, but water is only of limited use against an oil fire and in the sat image 40 minutes later there was still smoke visible)

Any thermal protection on the stage, be it SPAM or cork or anything else ablative would likely have been consumed by then. The same goes for non-fire proof components of the stage. Wire insulations, hoses, possibly carbon fibre structures.

As it was burning in the open, the kerosene fire wouldn't have been hot enough to set aluminium on fire (Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?) but likely hot enough - and long enough to partially melt it, or at least soften it enough to loose its shape under its own weight and deform.

Whether the legs would have survived that depends on the thickness of material and the resin used.

This is a very informative PDF on fire behaviour or aviation carbon composites:

http://www.fire.tc.faa.gov/pdf/07-57.pdf

Continued application of an external flame source is sort of the weak point of carbon fibre structures. If the resin itself is flammable, it would burn kinda like wood, gassing out burning vapors and leaving behind an empty husk of charred fibres with no cohesion to each other. If they are also in contact with the RP-1 there might also be a wick-effect - where RP-1 is being soaked up by delaminated composites through capillary effects and burns very efficiently from its surface, like wax on a candle wick.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: enzo on 06/20/2016 11:27 pm
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/20/2016 11:54 pm
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.

Cute.

But Google Aluminum.   QED. 
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/20/2016 11:58 pm
FYI...
https://www.youtube.com/watch?v=w608hwWqRQI

Wow - lovely - I wouldn't have imagined.  What resin is that?
Not sure specifically in that video but it could be something like PyroSic, an inorganic glass/ceramic matrix. It comes from motor-sports and AAR (All American Racing) builds race cars who also happened to build the legs on Falcon. Used for turbine hot sections as well.

http://www.compositesworld.com/articles/resins-for-the-hot-zone-part-ii-bmis-ces-benzoxazines-and-phthalonitriles
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: chalz on 06/21/2016 05:28 am
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.

Cute.

But Google Aluminum.   QED.
According to my searching the one thing Davy never called it was Aluminium so Enzo is rude about him for no reason. And to answer Covus' enquiry I couldn't find a definitive explanation. The presumption might be that they are using Davy's settled choice - he called it Alumium initially, then Aluminum. An apocryphal alternative is that early in the life of Alcoa it was misspelled on stationary (from Aluminium) but the misspelling stuck and their dominance cemented the usage in America.

*Also you can't say QED when you have asked someone to do the work, you have to do the demonstrating. :P
*Also https://xkcd.com/386/  :-X
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Comga on 06/21/2016 06:42 am
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.

Cute.

But Google Aluminum.   QED.
According to my searching the one thing Davy never called it was Aluminium so Enzo is rude about him for no reason. And to answer Covus' enquiry I couldn't find a definitive explanation. The presumption might be that they are using Davy's settled choice - he called it Alumium initially, then Aluminum. An apocryphal alternative is that early in the life of Alcoa it was misspelled on stationary (from Aluminium) but the misspelling stuck and their dominance cemented the usage in America.

*Also you can't say QED when you have asked someone to do the work, you have to do the demonstrating. :P
*Also https://xkcd.com/386/  :-X

Lighten up, and can we get back on topic?
See, CorvusCorax and enzo? You can't crack nerd jokes, even good ones, around here without starting a nerd battle.
Let's just take his point and continue:  The legs were probably not incinerated, so what happened to them and where are they?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Steven Pietrobon on 06/21/2016 06:54 am
Let's just take his point and continue:  The legs were probably not incinerated, so what happened to them and where are they?

The legs are still there, just badly damaged. The black object looks like a leg to me.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsnellenberger on 06/21/2016 02:21 pm
Let's just take his point and continue:  The legs were probably not incinerated, so what happened to them and where are they?

The legs are still there, just badly damaged. The black object looks like a leg to me.

I'm sorry, but you'll have to be a little more specific here...  :)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Kabloona on 06/21/2016 02:54 pm
Quote
I'm sorry, but you'll have to be a little more specific here... 

More specifically, the black object looks like *half* a leg.  ;)
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Mike_1179 on 06/21/2016 03:05 pm
Let's just take his point and continue:  The legs were probably not incinerated, so what happened to them and where are they?

The legs are still there, just badly damaged. The black object looks like a leg to me.

I'm sorry, but you'll have to be a little more specific here...  :)

Here's a before image of a leg. https://pbs.twimg.com/media/BJSV3UQCAAITfKN.jpg

Compare that to this
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: meekGee on 06/21/2016 11:04 pm
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.

Cute.

But Google Aluminum.   QED.
According to my searching the one thing Davy never called it was Aluminium so Enzo is rude about him for no reason. And to answer Covus' enquiry I couldn't find a definitive explanation. The presumption might be that they are using Davy's settled choice - he called it Alumium initially, then Aluminum. An apocryphal alternative is that early in the life of Alcoa it was misspelled on stationary (from Aluminium) but the misspelling stuck and their dominance cemented the usage in America.

*Also you can't say QED when you have asked someone to do the work, you have to do the demonstrating.
*Also https://xkcd.com/386/  :-X

Lighten up, and can we get back on topic?
See, CorvusCorax and enzo? You can't crack nerd jokes, even good ones, around here without starting a nerd battle.
Let's just take his point and continue:  The legs were probably not incinerated, so what happened to them and where are they?
We're as light as an aluminium lithum alloy
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: psionedge on 06/22/2016 04:42 am
(Anyone know the reason why is it called 'aluminum' by Americans? I mean, they don't call Strontium Strontum or Barium Barum - who misspelled Aluminium and had it stick?)
It was foolishly misspelled by the British lad who named it, Sir Humphry Davy. By the way, platinum and molybdenum called and they object to your insensitivity.

Cute.

But Google Aluminum.   QED.
Cute. But here's the google fight: http://www.googlefight.com/aluminum-vs-aluminium.php
Aluminum 100 - 14 Aluminium
Quite the shellacking...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Jim on 06/22/2016 12:52 pm

The same would have happened here. We have lot's of RP-1 spilled, but no oxidizer but air. So instead of a quick RUD, we have hundreds of liters spilled on deck, pooling around the debris, and burning continuously.

Wrong.  It would not pool.  It is under pressure and there would still be some LOX.  It would have fireballed.  Like a rocket crashes

and in the sat image 40 minutes later there was still smoke visible)


What smoke?  It was clouds.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: rsnellenberger on 06/22/2016 05:04 pm

The same would have happened here. We have lot's of RP-1 spilled, but no oxidizer but air. So instead of a quick RUD, we have hundreds of liters spilled on deck, pooling around the debris, and burning continuously.

Wrong.  It would not pool.  It is under pressure and there would still be some LOX.  It would have fireballed.  Like a rocket crashes

and in the sat image 40 minutes later there was still smoke visible)


What smoke?  It was clouds.

How much RP-1 remain in the 9 Merlin engine's regen cooling tubes after shutdown - liters, gallons?   I'm mindful of the first regen-engine Falcon-1, where the thrust from the residual fuel after shutdown was sufficient to push the first stage back into the second stage...
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cambrianera on 06/22/2016 05:11 pm
A broken nozzle would dump pressurized RP-1 into the surrounding area.
Only RP-1, not LOX.
This would explain the black smoke around the rocket, and the lack of fireball.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: envy887 on 06/22/2016 05:40 pm
How much RP-1 remain in the 9 Merlin engine's regen cooling tubes after shutdown - liters, gallons?   I'm mindful of the first regen-engine Falcon-1, where the thrust from the residual fuel after shutdown was sufficient to push the first stage back into the second stage...

Wasn't that F1 nozzle ablative and not regen cooled? Should be no RP-1 in there.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: whitelancer64 on 06/22/2016 05:59 pm
How much RP-1 remain in the 9 Merlin engine's regen cooling tubes after shutdown - liters, gallons?   I'm mindful of the first regen-engine Falcon-1, where the thrust from the residual fuel after shutdown was sufficient to push the first stage back into the second stage...

Wasn't that F1 nozzle ablative and not regen cooled? Should be no RP-1 in there.

The Merlin 1A and 1B (never flown) were ablative. The Merlin 1C and 1D are regeneratively cooled.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: envy887 on 06/22/2016 06:12 pm
How much RP-1 remain in the 9 Merlin engine's regen cooling tubes after shutdown - liters, gallons?   I'm mindful of the first regen-engine Falcon-1, where the thrust from the residual fuel after shutdown was sufficient to push the first stage back into the second stage...

Wasn't that F1 nozzle ablative and not regen cooled? Should be no RP-1 in there.

The Merlin 1A and 1B (never flown) were ablative. The Merlin 1C and 1D are regeneratively cooled.

Nevermind, the recontact was on a later Falcon 1 with the regen cooled Merlin 1-C. I thought it was on the second flight. Would there be enough RP-1 in the cooling plumbing to cause that much smoke?
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: cambrianera on 06/22/2016 06:53 pm
http://forum.nasaspaceflight.com/index.php?topic=32983.msg1469792#msg1469792
The nozzles do have cooling passages. On one of the pics with them in the Octo you can sorta see the drain plugs (very small allen plug) near the bottom edge. As far as material and what flows in it I can't speak to that  ;)

Drain plugs circled in red. Nozzle bells are part of regenerative RP-1 flow.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/22/2016 07:47 pm
From "Tony the Video Master"  update post! :)

There are your pancaked engine bells (4:33) Doug! ;D

https://www.youtube.com/watch?v=-SRhuQji2nw
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: sevenperforce on 06/22/2016 07:52 pm
A rare look at the other end of the octaweb (1:25). Presumably everything else went kablooey...pretty cleanly.

(4:33) Accordioned indeed.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Rocket Science on 06/22/2016 08:36 pm
A rare look at the other end of the octaweb (1:25). Presumably everything else went kablooey...pretty cleanly.

(4:33) Accordioned indeed.
Looks to be a leg behind it on the deck as it was lifted up....
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Space Ghost 1962 on 06/22/2016 08:40 pm
Less damage post entry burn around stage outer base above engine nozzles, possibly less hot gas intrusion inside the octoweb. Can anyone make out the top nozzle "gaskets"?

Hard to gauge with the impact damage. Pity that the terminal guidance / landing burn failed, it might have been that this one showed certain improvements obscured by other damage.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Fluke72 on 06/23/2016 04:34 am
http://forum.nasaspaceflight.com/index.php?topic=32983.msg1469792#msg1469792
The nozzles do have cooling passages. On one of the pics with them in the Octo you can sorta see the drain plugs (very small allen plug) near the bottom edge. As far as material and what flows in it I can't speak to that  ;)

Drain plugs circled in red. Nozzle bells are part of regenerative RP-1 flow.
correct and fyi the nozzle when drained post test runs equals 3-4 gallons.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: pechisbeque on 09/05/2016 09:56 pm
I'll class this as an update - but please discuss in the discussion thread to keep this thread purely on updates.

So what happened? Based on the unusual silence from all parties, various assumptions (yikes, "ain't nobody got time for that"!) and folk at the Cape, it would appear ULA and SpaceX had their bookings lined up at the Cape, but after the scrub on Thursday, and potentially as late as on the day on Friday, the NROL folk said "hold on, I know there's very little chance of a problem, but I don't want our very expensive spy sat at ANY risk while still out there on top of the Delta IV-H" based on the tiny chance the F9 had a bad day during the Static Fire (not that I assume a F9 RUD on SLC-40 would result in harm coming to SLC-37....but I suppose if there's even a slim chance, that was the concern...you don't want a flying grid fin impacting on national security, do you!).

Or it could all be bollocks, but until someone gives us an official statement, which is unlikely if the above is correct, that's what I'm thinking.

Was there ever any confirmation of this theory? If correct, it seems like a remarkably prescient request from the NRO.
It seems no one cared this much about OSIRIS-REx despite being even closer to SLC-40.  :'(
I'm glad everything is fine.
Title: Re: SpaceX Falcon 9 - Eutelsat 117W B & ABS 2A - SLC-40 - June - DISCUSSION
Post by: Robotbeat on 09/06/2016 01:45 pm
I'll class this as an update - but please discuss in the discussion thread to keep this thread purely on updates.

So what happened? Based on the unusual silence from all parties, various assumptions (yikes, "ain't nobody got time for that"!) and folk at the Cape, it would appear ULA and SpaceX had their bookings lined up at the Cape, but after the scrub on Thursday, and potentially as late as on the day on Friday, the NROL folk said "hold on, I know there's very little chance of a problem, but I don't want our very expensive spy sat at ANY risk while still out there on top of the Delta IV-H" based on the tiny chance the F9 had a bad day during the Static Fire (not that I assume a F9 RUD on SLC-40 would result in harm coming to SLC-37....but I suppose if there's even a slim chance, that was the concern...you don't want a flying grid fin impacting on national security, do you!).

Or it could all be bollocks, but until someone gives us an official statement, which is unlikely if the above is correct, that's what I'm thinking.

Was there ever any confirmation of this theory? If correct, it seems like a remarkably prescient request from the NRO.
It seems no one cared this much about OSIRIS-REx despite being even closer to SLC-40.  :'(
I'm glad everything is fine.
NRO has been around long enough to remember pad explosions. And those birds are ridiculously expensive.