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SpaceX Vehicles and Missions => SpaceX Missions Section => Topic started by: Galactic Penguin SST on 02/21/2014 07:00 AM

Title: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Galactic Penguin SST on 02/21/2014 07:00 AM
Discussion Thread for the SpaceX Falcon 9 / SES-9 mission.

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.

SES-9 is a Boeing BSS-702HP satellite ordered back in October 2012: http://www.boeing.com/boeing/defense-space/ic/sis/features.page? (http://www.boeing.com/boeing/defense-space/ic/sis/features.page?)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/21/2014 12:51 PM
Well the dice and moolah are definitely rolling in.....  ::)

Peter B. de Selding ‏@pbdes
SES adds another SpaceX Falcon 9: After yesterday's SES-10 for late 2016 over LatinAm, co. says AsiaPac SES-9 to launch on F9 in early 2015.

SES-9 is a Boeing BSS-702HP satellite ordered back in October 2012: http://www.boeing.com/boeing/defense-space/ic/sis/features.page? (http://www.boeing.com/boeing/defense-space/ic/sis/features.page?)

Wonder what the mass will be?  One 702 was 5900 kg (Inmarsat-5), but Mexsat was 5400 kg.  Presumably this will be at the very low end of the range, since the Falcon can't do any more, the satellite is designed for Xenon propuslsion, and it's got very high power solar panels.

http://www.boeing.com/boeing/defense-space/space/bss/factsheets/702/702fleet.page

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Herb Schaltegger on 02/21/2014 02:09 PM
Good question about the mass. Directv 10, 11 and 12 are based on the Boeing 702 bus as well, but massed over 6,000 kg at launch. However, the claimed "start of life" on-orbit mass, per the Boeing fact sheet released at the time, was only 3,700 kg. D10 and 12 were launched by Proton, so perhaps a lot of that mass was necessary due to the inclination of the launch site. D11 was launched by SeaLaunch so that wouldn't apply, obviously.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/21/2014 02:11 PM
Lots of complication and flexibility, here. Lots of that mass must be propellant for orbital inclination, and if you take your time, you can use electric propulsion to do orbit insertion, so that gives the customer a lot of margin for negotiating with launch providers.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/21/2014 05:41 PM
Ariane 5, Proton-M and Sea Launch all quote the same delta-v deficit to GSO: 1,500m/s. Save for the American launchers 1,500m/s is the stock GTO. Supersynchronous might earn you a few percents, but I still can't believe the Falcon 9 v1.1 would do so much.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/21/2014 06:10 PM
Also by Peter B. Selding:

Quote
Peter B. de Selding ‏@pbdes 3h
SES: 'SES-9 sat to launch on SpaceX Falcon 9 will weigh ~5,330kg at launch into a sub-synchronous orbit.' Nearing rocket's capacity ceiling.
So this will be a subsynchronous mission.

And

Quote
Peter B. de Selding ‏@pbdes 7h

SES's Bausch: 2 new deals w/ SpaceX Falcon9 part of original contract (1 firm, 3 options) including SES 8 in Dec. 1 more sat left to assign.
We can expect an additional SES/SpaceX launch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sweet-d on 02/23/2014 02:32 AM
As always more good news for spacex
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 04/11/2014 07:38 AM
http://www.spacenews.com/article/launch-report/40165ses-books-spacex-falcon-9-for-hybrid-satellite%E2%80%99s-debut


Quote
Speaking here April 10 during the Space Access conference organized by Astech Paris Region, Olivier Lebrethon, SES manager for new launch risks...<snip>...said that for SES-9, the company will use both the electric propulsion and chemical propulsion systems to reach final geostationary position about three months after launch — much longer than using chemical only, but shorter than an all-electric solution. The satellite is scheduled for launch in 2015.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Galactic Penguin SST on 01/22/2015 02:28 PM
Interesting to see that the launch of SES-9 may use the higher thrust Merlin 1D engines.

Peter B. de Selding @pbdes
SES: We may skip spring SpaceX launch slot & wait till mid-year to let someone else be 1st using Falcon 9 main engine in full-thrust regime.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevin-rf on 01/22/2015 02:39 PM
What does that even mean? Merlin 1D rev 2?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Galactic Penguin SST on 01/22/2015 02:45 PM
What does that even mean? Merlin 1D rev 2?

Didn't Elon Musk said that the Merlin 1D as is could actually go for a higher thrust soon?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/22/2015 02:57 PM
Huh. The elusive F9 performance numbers just got even more elusive. Real vs. published numbers vs. caveats going along with those published numbers...

Also, the guys working F9 certification will love this change, I'm sure  ::)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jarnis on 01/22/2015 03:24 PM
Heh, Merlin 1Ds remind me of today's processors and graphics cards.

"What is the performance of this thing?" - "Well, it depends..."
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 01/22/2015 03:26 PM
What does that even mean? Merlin 1D rev 2?

Didn't Elon Musk said that the Merlin 1D as is could actually go for a higher thrust soon?

Yes, it sounds like the 165klbf sea level thrust uprating discussed here:

http://forum.nasaspaceflight.com/index.php?topic=32983.msg1131598#msg1131598

And the original quote from Elon referencing the 165klbf number:

http://forum.nasaspaceflight.com/index.php?topic=32998.msg1130641#msg1130641
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/22/2015 04:20 PM
The fabeled 16.67 tonne NLS-2 no holds barred F9?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dudely on 01/22/2015 04:30 PM
It is likely that this increase is coming now because of propellant densification? That is, they wish to keep the same T/W, but with more total fuel available?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 01/22/2015 05:01 PM
Huh. The elusive F9 performance numbers just got even more elusive. Real vs. published numbers vs. caveats going along with those published numbers...

Also, the guys working F9 certification will love this change, I'm sure  ::)

Upgrades happen. RS-68A didn't cause the entire Delta IV to be re-certified, and this would be even less of a change.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 01/23/2015 03:16 AM
Huh. The elusive F9 performance numbers just got even more elusive. Real vs. published numbers vs. caveats going along with those published numbers...

Also, the guys working F9 certification will love this change, I'm sure  ::)

Upgrades happen. RS-68A didn't cause the entire Delta IV to be re-certified, and this would be even less of a change.

Do we know there are changes to M1D in order to get higher thrust levels ?
If there aren't, I don't see how this would change certification, DoD might consider those higher thrust levels uncertified initially, pending enough successful launches using higher thrust levels before certifying that.
If there are changes, the unchanged version of the engine would be available for DoD launches. They don't have to certify the new version until there is enough launch data to certify this mod.
The real issue is if this causes reliability problems. I'm sure SpaceX has tested those higher thrust levels at the stand (or the new version) to exhaustion before using that in a launch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MP99 on 01/23/2015 09:03 AM


Huh. The elusive F9 performance numbers just got even more elusive. Real vs. published numbers vs. caveats going along with those published numbers...

Also, the guys working F9 certification will love this change, I'm sure  ::)

Upgrades happen. RS-68A didn't cause the entire Delta IV to be re-certified, and this would be even less of a change.

Do we know there are changes to M1D in order to get higher thrust levels ?
If there aren't, I don't see how this would change certification, DoD might consider those higher thrust levels uncertified initially, pending enough successful launches using higher thrust levels before certifying that.
If there are changes, the unchanged version of the engine would be available for DoD launches. They don't have to certify the new version until there is enough launch data to certify this mod.
The real issue is if this causes reliability problems. I'm sure SpaceX has tested those higher thrust levels at the stand (or the new version) to exhaustion before using that in a launch.

Certification is a government thing.

This is simply a commercial organisation assessing a risk, and costs associated with minimising that risk. As you say "the real issue is if this causes reliability problems."

Running the M1D @ 112% looks like it will reduce margins in both engines and vehicle structure. It occurs to me that recovering an intact stage would allow engineers to look for any signs of margins being less than expected, which could reduce the risk from increased thrust.

Cheers, Martin
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MP99 on 01/23/2015 09:05 AM
Interesting to see that the launch of SES-9 may use the higher thrust Merlin 1D engines.

Peter B. de Selding @pbdes
SES: We may skip spring SpaceX launch slot & wait till mid-year to let someone else be 1st using Falcon 9 main engine in full-thrust regime.

Hmm, sounds like a 112% flight is closer than we'd realised.

Cheers, Martin
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: notsorandom on 01/23/2015 01:50 PM
It is likely that this increase is coming now because of propellant densification? That is, they wish to keep the same T/W, but with more total fuel available?
That could be but they would see a benefit to their payload capacity even without increasing the amount of propellant. A higher T/W means less time fighting gravity. The Antares launch vehicle is swapping out its engines without a propellant increase and it is getting a better payload capacity. Because engine thrust is pretty tightly correlated with the expense of the engine and tanks and propellant are relatively cheap designers typically have optimized on getting the most out of a given amount of thrust rather then a given amount of propellant. So most rockets without optional add on boosters have a pretty low T/W. The Russians have a few that buck this trend for various reasons.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: 2552 on 01/30/2015 11:40 PM
Space News: SES Rethinking Being First To Fly a Full-throttle Falcon 9 (http://spacenews.com/ses-rethinking-being-first-to-fly-on-a-full-throttle-falcon-9/)

Quote
“You know SpaceX is introducing into their manifest ... a modification of the current engine, with about a 20 percent increase in thrust," said Martin Halliwell, SES’s chief technical officer. "We’re making a decision internally as to whether we want to be the first to fly it.”
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zardar on 02/20/2015 09:54 AM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given CRS-6 in ~April, and CRS-7 in ~June, that would most likely put SES-9 in May?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: TrevorMonty on 02/20/2015 10:39 AM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines. They did this in beginning of 2014 with a 3D printed part fitted to one of the engines. One of the many bonuses of having multiple engines.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zardar on 02/20/2015 11:09 AM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines. They did this in beginning of 2014 with a 3D printed part fitted to one of the engines. One of the many bonuses of having multiple engines.

Its possible the "upgraded" engine may have flown, but this will be the first time it will have flown with the increased thrust.

And even "upgraded" may be a misnomer, since they may well be the same engines, just qualified for the higher output, along with perhaps control software upgrades and changes to propellant flow/ratios etc.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 02/20/2015 12:54 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:

Quote
SES: What a difference 1 sat makes: If SpaceX launches SES-9 in Q2, 2015-2017 CAGR is 5%. If in Q3, CAGR is 3.5%. Co has 54-sat fleet.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: eweilow on 02/20/2015 12:55 PM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines. They did this in beginning of 2014 with a 3D printed part fitted to one of the engines. One of the many bonuses of having multiple engines.

Its possible the "upgraded" engine may have flown, but this will be the first time it will have flown with the increased thrust.

And even "upgraded" may be a misnomer, since they may well be the same engines, just qualified for the higher output, along with perhaps control software upgrades and changes to propellant flow/ratios etc.

It will especially be the first time it flies with all nine engines having higher thrust figures.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Antares on 02/20/2015 12:56 PM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines.

Wrong
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/20/2015 12:58 PM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines.

Wrong
Actually, right. They flew a Merlin that had a 3D printed LOx valve on one of their previous flights.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: TrueBlueWitt on 02/20/2015 01:07 PM
Space News: SES Rethinking Being First To Fly a Full-throttle Falcon 9 (http://spacenews.com/ses-rethinking-being-first-to-fly-on-a-full-throttle-falcon-9/)

Quote
“You know SpaceX is introducing into their manifest ... a modification of the current engine, with about a 20 percent increase in thrust," said Martin Halliwell, SES’s chief technical officer. "We’re making a decision internally as to whether we want to be the first to fly it.”

120%? That's 175klb. I don't think we've seen anything over 112% before for the upgrade have we?  This is along with densification would allow enough margin for boost back even with com SATs? How they get to 53t Without cross feed for FH?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Antares on 02/20/2015 01:10 PM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines.
Wrong
Actually, right. They flew a Merlin that had a 3D printed LOx valve on one of their previous flights.

Sigh.  I deleted the part about the DMLS valve.  He said he doubts it's the first flight of the engine.  I said wrong.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dudely on 02/20/2015 02:37 PM
Agreed, there is no way for them to test this without doing it to all engines at once. That goes for propellent densification as well as increased thrust.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/20/2015 02:40 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:

Quote
SES: What a difference 1 sat makes: If SpaceX launches SES-9 in Q2, 2015-2017 CAGR is 5%. If in Q3, CAGR is 3.5%. Co has 54-sat fleet.
Here's my thinking on their thinking, obviously guessing.

From the second SES quote above, a Q2 launch helps their bottom line.  So request a Q2 launch on the old F9, or the enhanced?  Assuming no more fuel, improved thrust helps only gravity losses + a tiny boost to ISP.  Gravity losses are typically 1-1.5 km/sec.  The exact calculations are complex (more power helps a lot at takeoff, but not at all when acceleration limited, drag values go up, etc.) Make a wild guess and say losses are reduced by 10%, or 150 m/s or so.  That gives them 150 m/s more for GTO injection, which translates (not 1:1, but not too far different) to 150 m/s less needed by the satellite.  Since GEO stationkeeping is around 50 m/s per year, that's 3 years of extra life.

So I think that's the gamble - 3 years of extra life vs. extra risk of exploding on the pad.  So which way to bet?   If the satellite lasts for 15 years, then the expected years of life lost is failure probability x 15. So if there's less than a 20% chance of blowing up, go for the extra life.  SpaceX must have convinced them the odds of failure are less than 20%. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Eerie on 02/20/2015 04:36 PM
Agreed, there is no way for them to test this without doing it to all engines at once. That goes for propellent densification as well as increased thrust.

Hmm...

Why not put a new engine in the middle position and run it with increased thrust?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Barrie on 02/20/2015 04:44 PM
I was wondering if the recent extra-loud test at McGregor might have been something to do with convincing SES the uprating is safe.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zardar on 02/20/2015 04:47 PM
Here's my thinking on their thinking, obviously guessing.

That gives them 150 m/s more for GTO injection, which translates (not 1:1, but not too far different) to 150 m/s less needed by the satellite.  Since GEO stationkeeping is around 50 m/s per year, that's 3 years of extra life.


Also, with the electric thruster used for apogee-raising on the sat, it takes 4-6 months to raise the sat to GSO.
If a more powerful F9 can lift it higher, not only will it save sat lifetime, it can get into a position to start earning revenue several months sooner. That will pull future revenue into 2015, making the beancounters very happy when it comes to preparing the annual accounts.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/20/2015 05:12 PM
I doubt this is first flight of this engine, they have been testing modified engines by flying 1 in F9 along with 8 standard/proven engines.
Wrong
Actually, right. They flew a Merlin that had a 3D printed LOx valve on one of their previous flights.

Sigh.  I deleted the part about the DMLS valve.  He said he doubts it's the first flight of the engine.  I said wrong.
But this is the Internet, so anything you say (or that people think you say) will be picked apart for the most inconsequential, cosmetic flaw. ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: TrevorMonty on 02/20/2015 05:29 PM
Agreed, there is no way for them to test this without doing it to all engines at once. That goes for propellent densification as well as increased thrust.

Hmm...

Why not put a new engine in the middle position and run it with increased thrust?
They can run one at max power and throttle back the ones around it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MTom on 02/20/2015 06:58 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:


I wouldn't be surprised if this was part of a dealing for some discount of the launch price too.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 02/20/2015 07:15 PM
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Barrie on 02/20/2015 07:20 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:


I wouldn't be surprised if this was part of a dealing for some discount of the launch price too.
Yes, but I suspect it is money off a future launch rather than off this one, where the ink is already dry.  It's probably more than a free beanie for spending more than $50.   :D
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ChrisWilson68 on 02/20/2015 07:29 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:


I wouldn't be surprised if this was part of a dealing for some discount of the launch price too.
Yes, but I suspect it is money off a future launch rather than off this one, where the ink is already dry.  It's probably more than a free beanie for spending more than $50.   :D

I agree.  I wouldn't be surprised if the earlier public statements from SES about choosing not to be the first customer for the uprated F9 were really just part of the negotiations with SpaceX to win more concessions on some future launch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mme on 02/20/2015 07:43 PM
According to Peter B. de Selding from SpaceNews:
"SES: We have decided to be inaugural customer for enhanced-version SpaceX Falcon 9 main engine, w/ our SES-9 aiming for Q2 launch."

Given SES' previously stated uncertainty about being the inaugural customer, I think it's interesting why they decided to do it (besides, obviously, being confident in data from SpaceX about any risks). I wonder if Peter B. de Selding's other tweet (https://twitter.com/pbdes/status/568717723552915456) gives a clue:


I wouldn't be surprised if this was part of a dealing for some discount of the launch price too.
Yes, but I suspect it is money off a future launch rather than off this one, where the ink is already dry.  It's probably more than a free beanie for spending more than $50.   :D

I agree.  I wouldn't be surprised if the earlier public statements from SES about choosing not to be the first customer for the uprated F9 were really just part of the negotiations with SpaceX to win more concessions on some future launch.

I think they reviewed the data and decided it seemed "safe enough" and they want to start making money ASAP.  As per:
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Barrie on 02/20/2015 08:12 PM
I think they reviewed the data and decided it seemed "safe enough" and they want to start making money ASAP.  As per:
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/

Oh, that too.  Multiple factors play into most decisions, I think.  If it was all about that rational analysis, why play hard-to-get so publicly ie tweeting 'we are not sure about this'?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/20/2015 08:43 PM
On the subject of SES-9 itself, the previously linked article states:
Quote
SES-9 is one of several satellites SES has ordered that will use electric propulsion to climb from the rocket’s drop-off point to final geostationary orbit 36,000 kilometers over the equator. Electric propulsion accords huge savings in a satellite’s launch mass compared to chemical propellant, but at a price: The satellite takes several months, not weeks, to reach its operating position.
So far, so good.  But the previous article http://spacenews.com/ses-rethinking-being-first-to-fly-on-a-full-throttle-falcon-9/ notes:
Quote
SES-9, a Boeing Space and Intelligence Systems 702-HP spacecraft expected to weigh 5,300 kilograms at launch, is near the limit of what the current Falcon 9 v1.1 vehicle can carry and was to be placed into a subsynchronous orbit.SES-9 then would use its on-board propulsion to climb to final geostationary orbit.

5.3 metric tons is a pretty darn substantial size, and this is with "huge mass savings" due to being all-electric.  What would it have weighed with a conventional chemical engine for orbit raising/circularization?  Something north of 6 tons?

Also of note in that article:
Quote
One of the benefits of the Merlin 1D performance upgrade is that it will permit SpaceX to launch payloads with the same maximum weight as it does currently while at the same time preserving capacity so that the first stage can power itself to an unmanned oceangoing barge to be recovered and reused.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/20/2015 09:13 PM
Here's my thinking on their thinking, obviously guessing.

That gives them 150 m/s more for GTO injection, which translates (not 1:1, but not too far different) to 150 m/s less needed by the satellite.  Since GEO stationkeeping is around 50 m/s per year, that's 3 years of extra life.
Also, with the electric thruster used for apogee-raising on the sat, it takes 4-6 months to raise the sat to GSO.  If a more powerful F9 can lift it higher, not only will it save sat lifetime, it can get into a position to start earning revenue several months sooner. That will pull future revenue into 2015, making the beancounters very happy when it comes to preparing the annual accounts.
I don't think this is correct.  The overall magnitude of the orbit raising is 1500-1800 m/s.  The better F9 can only affect this by 100-150 m/sec or so.  So it only reduces the thrusting time by a week or two.  Launching earlier, on the other hand, can save months.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: swervin on 02/21/2015 02:24 PM
Strictly a question, not conjecture or rumor starting:

Is it possible SpX reworked the financial details of the contract; sweeting the deal for SES to 'be the first?'

I've seen no articles to date mention anything to this effect, but I believe SpX has done this in the past for 'first customers?'... I think?

Thanks,
Splinter
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/21/2015 03:20 PM
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/

Quote
SES Chief Financial Officer Padraig McCarthy said during the conference call that if SES-9 is launched by June, SES’s average annual revenue between 2015 and 2017 is likely to grow by 4 percent. If the launch slips beyond June, the compound annual revenue growth will be just 3.5 percent.

That was not what the stock market wanted to hear, and despite a 10 percent increase in the SES dividend and the generally positive effects on SES of the rising U.S. dollar, the company’s shares fell by some 4.5 percent Feb. 20.

Seems to me that's the crux of it right there. SpaceX may not have had to sweeten the deal at all.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Llian Rhydderch on 02/21/2015 11:59 PM
Strictly a question, not conjecture or rumor starting:

Is it possible SpX reworked the financial details of the contract; sweeting the deal for SES to 'be the first?'

I've seen no articles to date mention anything to this effect, but I believe SpX has done this in the past for 'first customers?'... I think?

Thanks,
Splinter

And that is a good question. 

It is clear to me that:
1) SpaceX often changes the elements that make up the launch service product offering mix: price, product, detailed terms and conditions.
2) Most of these details are proprietary to individual launch contracts between SpaceX and their customers, and are not something a bunch of folks on the internet are privy to.  (even the folks who are enmeshed in the technical flow of launch vehicles and payloads and work for some private or government entity involved with launch services or payloads.)

But, hey, this is the internet.  So many will opine on such matters with more certainty in their locution than they have any knowledge that would support.


Edit:  clarified a thought.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 02/23/2015 04:32 AM
I don't think they would go for it unless they felt it was safe. This is a big bird for them, launching it on a vehicle they weren't sure about would be bad risk management.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 02/23/2015 12:26 PM
On the subject of SES-9 itself, the previously linked article states:
Quote
SES-9 is one of several satellites SES has ordered that will use electric propulsion to climb from the rocket’s drop-off point to final geostationary orbit 36,000 kilometers over the equator. Electric propulsion accords huge savings in a satellite’s launch mass compared to chemical propellant, but at a price: The satellite takes several months, not weeks, to reach its operating position.
So far, so good.  But the previous article http://spacenews.com/ses-rethinking-being-first-to-fly-on-a-full-throttle-falcon-9/ notes:
Quote
SES-9, a Boeing Space and Intelligence Systems 702-HP spacecraft expected to weigh 5,300 kilograms at launch, is near the limit of what the current Falcon 9 v1.1 vehicle can carry and was to be placed into a subsynchronous orbit.SES-9 then would use its on-board propulsion to climb to final geostationary orbit.

5.3 metric tons is a pretty darn substantial size, and this is with "huge mass savings" due to being all-electric.  What would it have weighed with a conventional chemical engine for orbit raising/circularization?  Something north of 6 tons?

SES-9 is not an all-electric satellite.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/23/2015 01:58 PM
SES-9 is not an all-electric satellite.

Seems you are correct based on Gunter's: http://space.skyrocket.de/doc_sdat/ses-9.htm
Quote
The spacecraft will carry a xenon ion propulsion system (XIPS) for all on-orbit maneuvering and a chemical bi-propellant system for initial orbit raising.
but Space News says:
Quote
SES-9 is one of several satellites SES has ordered that will use electric propulsion to climb from the rocket’s drop-off point to final geostationary orbit 36,000 kilometers over the equator. Electric propulsion accords huge savings in a satellite’s launch mass compared to chemical propellant, but at a price: The satellite takes several months, not weeks, to reach its operating position.

So, the reason it will take months to get to GSO is because it is being dropped off further from GSO than if it were to be launched on an Ariane V or Proton?  Even though it is using a chemical propellant to reach GSO?  And Space News is just wrong about electric being used to get to GSO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Antares on 02/23/2015 02:24 PM
I don't think they would go for it unless they felt it was safe. This is a big bird for them, launching it on a vehicle they weren't sure about would be bad risk management.

Good point, since it led me to another thought.  The only way a lower price would make sense, if the bird cannot be lost (note Eutelsat rolled the dice on the first of each EELV), is if underperformance is the main concern.  The SV would have to make up the underburn.  The lower price wouldn't make a measure for complete failure.  I suppose insurance costs could be moved from SES to SpaceX, and SpaceX could pay for a replacement bird and reflight; but that would be a lot of cost risk for the Hawthorneans.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 02/23/2015 02:34 PM
SES-9 is not an all-electric satellite.

Seems you are correct based on Gunter's: http://space.skyrocket.de/doc_sdat/ses-9.htm
Quote
The spacecraft will carry a xenon ion propulsion system (XIPS) for all on-orbit maneuvering and a chemical bi-propellant system for initial orbit raising.
but Space News says:
Quote
SES-9 is one of several satellites SES has ordered that will use electric propulsion to climb from the rocket’s drop-off point to final geostationary orbit 36,000 kilometers over the equator. Electric propulsion accords huge savings in a satellite’s launch mass compared to chemical propellant, but at a price: The satellite takes several months, not weeks, to reach its operating position.

So, the reason it will take months to get to GSO is because it is being dropped off further from GSO than if it were to be launched on an Ariane V or Proton?  Even though it is using a chemical propellant to reach GSO?  And Space News is just wrong about electric being used to get to GSO.

If you read the 702 description on that site (linked from the SES-9 page) it actually sounds like you have the option of using two different sets of thrusters for orbit raising depending on how much mass you want to end up with.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 02/23/2015 04:09 PM
If you read the 702 description on that site (linked from the SES-9 page) it actually sounds like you have the option of using two different sets of thrusters for orbit raising depending on how much mass you want to end up with.

From Boeing website http://www.boeing.com/boeing/defense-space/ic/sis/features.page (http://www.boeing.com/boeing/defense-space/ic/sis/features.page), one can find
- SES-9 has a liquid apogee engine
- electric orbit raising, even partial, is not depicted

so my feeling electrical thrusters are only used on-station; for sure it is not an all-electric sat.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Herb Schaltegger on 02/23/2015 11:48 PM
If you read the 702 description on that site (linked from the SES-9 page) it actually sounds like you have the option of using two different sets of thrusters for orbit raising depending on how much mass you want to end up with.

From Boeing website http://www.boeing.com/boeing/defense-space/ic/sis/features.page (http://www.boeing.com/boeing/defense-space/ic/sis/features.page), one can find
- SES-9 has a liquid apogee engine
- electric orbit raising, even partial, is not depicted

so my feeling electrical thrusters are only used on-station; for sure it is not an all-electric sat.

Just to let you know, that's pretty much verbatim from Boeing's 702HP spacecraft bus stock specs. It wouldn't be the first time that a public webpage used generic data that was simply incorrect in the as-built configuration.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/24/2015 03:40 AM
If you read the 702 description on that site (linked from the SES-9 page) it actually sounds like you have the option of using two different sets of thrusters for orbit raising depending on how much mass you want to end up with.

From Boeing website http://www.boeing.com/boeing/defense-space/ic/sis/features.page (http://www.boeing.com/boeing/defense-space/ic/sis/features.page), one can find
- SES-9 has a liquid apogee engine
- electric orbit raising, even partial, is not depicted

so my feeling electrical thrusters are only used on-station; for sure it is not an all-electric sat.

This graphic for a generic 702 mission shows the liquid apogee engine being used to raise perigee, then the XIPS to circularize, so the XIPS is not just for on-station.

http://www.boeing.com/assets/pdf/defense-space/space/bss/factsheets/702/wgs_flight_deployment.pdf
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 02/24/2015 07:58 AM
Kabloona, Herb, thank you.

So I understand this sat may perform a partial electrical orbit raising, wait and see !
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 03/02/2015 03:56 AM
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/

Elon just tweeted about upcoming F9 performance upgrades: https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mariusuiram on 03/02/2015 04:04 AM

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?

I was under the impression that you need to do all 3 otherwise the enhancement is tiny. That is, you cant just increase thrust without increasing fuel and expect a significant improvement.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 03/02/2015 04:06 AM
And the full write-up on the SES decision to fly first on the uprated F9

http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/

Elon just tweeted about upcoming F9 performance upgrades: https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?
I kind of doubt it'll all be that flight, but still WOW. Even a tank stretch! That's a significant performance boost, indeed! Not nearly as much as v1.0->v1.1 (which about doubled the performance to LEO and even more to GTO), but still big. And if it gets you first stage reuse for the payloads that used to need expending of the whole rocket... SpaceX just doesn't relent, do they?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 03/02/2015 04:07 AM
...I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?

I was under the impression that you need to do all 3 otherwise the enhancement is tiny. That is, you cant just increase thrust without increasing fuel and expect a significant improvement.
(PLEASE edit your quote tags!!!!)

Reducing gravity losses is not insignificant.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 03/02/2015 04:08 PM

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?

I was under the impression that you need to do all 3 otherwise the enhancement is tiny. That is, you cant just increase thrust without increasing fuel and expect a significant improvement.
Well, we can guess at some numbers.  Start with today's launch (EutelSat/ABS) as a benchmark.  If we want to make it re-usable, need to add legs and grid fins (assume 4t total) and save some fuel.  Assuming no boostback (barge landing) maybe 15t (This is a huge uncertainty in the calculation, and only SpaceX knows for sure).  So your empty mass is 19t more, and your fuel used 15t less.  Assuming ISP=311, empty stage=20t, upper stage mass=100t, you get a hit of 425 m/s at staging.  You need to make this up somehow.

First, higher thrust.  This reduces gravity losses, which are 1-1.5 km/sec on a typical rocket.  This depends a lot on the details of the trajectory, but make a wild guess and say a 10% improvement, or 150 m/sec.

Next, cooled fuel.  Say you can get 6% more fuel in each stage.   Now you lose some of your gravity loss gain, since your rocket weighs more, but you get about 225 m/s more delta-v.  So perhaps cooled fuel + higher thrust gives you 300 m/s.  Still too short to allow recovery on 4.2t satellite launches.

Now stretch the second stage by 10%.  This hurts the first stage delta-v by 150 m/s - it's pushing more mass.  But the second stage goes up by 300 m/s or so.   The overall gain of 450 m/s is now more than the re-use loss, and you can launch 4.2t satellites from the Cape and still recover the first stage.

Finally, moving to Texas helps by another 40 m/s (10 m/s for Earth rotation, 30 m/s less plane change). So the net result, I think, is at least 4.5t with recovery. 

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 03/02/2015 04:33 PM

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?

I was under the impression that you need to do all 3 otherwise the enhancement is tiny. That is, you cant just increase thrust without increasing fuel and expect a significant improvement.
Well, we can guess at some numbers.  Start with today's launch (EutelSat/ABS) as a benchmark.  If we want to make it re-usable, need to add legs and grid fins (assume 4t total) and save some fuel.  Assuming no boostback (barge landing) maybe 15t (This is a huge uncertainty in the calculation, and only SpaceX knows for sure).  So your empty mass is 19t more, and your fuel used 15t less.  Assuming ISP=311, empty stage=20t, upper stage mass=100t, you get a hit of 425 m/s at staging.  You need to make this up somehow.

First, higher thrust.  This reduces gravity losses, which are 1-1.5 km/sec on a typical rocket.  This depends a lot on the details of the trajectory, but make a wild guess and say a 10% improvement, or 150 m/sec.

Next, cooled fuel.  Say you can get 6% more fuel in each stage.   Now you lose some of your gravity loss gain, since your rocket weighs more, but you get about 225 m/s more delta-v.  So perhaps cooled fuel + higher thrust gives you 300 m/s.  Still too short to allow recovery on 4.2t satellite launches.

Now stretch the second stage by 10%.  This hurts the first stage delta-v by 150 m/s - it's pushing more mass.  But the second stage goes up by 300 m/s or so.   The overall gain of 450 m/s is now more than the re-use loss, and you can launch 4.2t satellites from the Cape and still recover the first stage.

Finally, moving to Texas helps by another 40 m/s (10 m/s for Earth rotation, 30 m/s less plane change). So the net result, I think, is at least 4.5t with recovery.

GTO payload increases to 4+ mT -- plus reuse -- could shatter the launch market for all-electric sat launches such as the dual 702SP launch just completed.  Imagine even a halving of the cost for a dual launch or a relatively large bird on a reflight vehicle a couple years hence... or launching this 5.3mT SES sat in expendible mode for $60M-ish.  Must be giving the Ariane folks nightmares!

Mods: this is a good discussion, but probably should be moved somewhere other than missions section
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 03/02/2015 05:33 PM

I wonder if all 3 enhancements - including the slight upper stage stretch(?) - will debut on this flight?

I was under the impression that you need to do all 3 otherwise the enhancement is tiny. That is, you cant just increase thrust without increasing fuel and expect a significant improvement.
Well, we can guess at some numbers.  Start with today's launch (EutelSat/ABS) as a benchmark.  If we want to make it re-usable, need to add legs and grid fins (assume 4t total) and save some fuel.  Assuming no boostback (barge landing) maybe 15t (This is a huge uncertainty in the calculation, and only SpaceX knows for sure).  So your empty mass is 19t more, and your fuel used 15t less.  Assuming ISP=311, empty stage=20t, upper stage mass=100t, you get a hit of 425 m/s at staging.  You need to make this up somehow.

First, higher thrust.  This reduces gravity losses, which are 1-1.5 km/sec on a typical rocket.  This depends a lot on the details of the trajectory, but make a wild guess and say a 10% improvement, or 150 m/sec.

Next, cooled fuel.  Say you can get 6% more fuel in each stage.   Now you lose some of your gravity loss gain, since your rocket weighs more, but you get about 225 m/s more delta-v.  So perhaps cooled fuel + higher thrust gives you 300 m/s.  Still too short to allow recovery on 4.2t satellite launches.

Now stretch the second stage by 10%.  This hurts the first stage delta-v by 150 m/s - it's pushing more mass.  But the second stage goes up by 300 m/s or so.   The overall gain of 450 m/s is now more than the re-use loss, and you can launch 4.2t satellites from the Cape and still recover the first stage.

Finally, moving to Texas helps by another 40 m/s (10 m/s for Earth rotation, 30 m/s less plane change). So the net result, I think, is at least 4.5t with recovery.

GTO payload increases to 4+ mT -- plus reuse -- could shatter the launch market for all-electric sat launches such as the dual 702SP launch just completed.  Imagine even a halving of the cost for a dual launch or a relatively large bird on a reflight vehicle a couple years hence... or launching this 5.3mT SES sat in expendible mode for $60M-ish.  Must be giving the Ariane folks nightmares!

Mods: this is a good discussion, but probably should be moved somewhere other than missions section
Yes, I second the motion, there's a reuse penalty thread in the reusable section, it's starting to go there too...   
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 03/21/2015 10:37 AM
hey is this launching before jason-3 or what (and if so will it have legs)? i cant imagine may and june going by without a single launch. I remember last year when shotwell claimed they'd be launching on a twice a month cadence this year.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 03/22/2015 03:55 AM
hey is this launching before jason-3 or what (and if so will it have legs)? i cant imagine may and june going by without a single launch. I remember last year when shotwell claimed they'd be launching on a twice a month cadence this year.

Am i gonna have to become an L2 member in order for someone to answer this? I would if it didn't cost 90 dollars a year!!!!!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Owlon on 03/22/2015 04:26 AM
hey is this launching before jason-3 or what (and if so will it have legs)? i cant imagine may and june going by without a single launch. I remember last year when shotwell claimed they'd be launching on a twice a month cadence this year.

Am i gonna have to become an L2 member in order for someone to answer this? I would if it didn't cost 90 dollars a year!!!!!

You should become an L2 member out of love for the site, not for information! (though it certainly is a nice incentive)  ;)

The public statements currently point to this launching in May and Jason-3 launching July 22. That was before the helium issue on the Turkmensat F9, so the schedule going forward may be impacted--currently it sounds like CRS-6 April 10th or so, and Turkmensat later in April. I wouldn't expect SES-9 to slip past May, personally. As far as legs and recovery go, I have no clue.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 03/22/2015 07:02 AM
You should become an L2 member out of love for the site, not for information! (though it certainly is a nice incentive)  ;)

The public statements currently point to this launching in May and Jason-3 launching July 22. That was before the helium issue on the Turkmensat F9, so the schedule going forward may be impacted--currently it sounds like CRS-6 April 10th or so, and Turkmensat later in April. I wouldn't expect SES-9 to slip past May, personally. As far as legs and recovery go, I have no clue.

There has to be legs on ses-9, i mean thats exactly what the upgrade is for to be able to retrieve the booster "on all types of launches" (am i correct here?)

if there aren't legs on ses-9 then why the upgrade?

edit/Lar: Fix quotes and while I was at it, remove needless wording. Please fix your own quotes people. It's not that hard, usually.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Hauerg on 03/22/2015 07:36 AM
...
 As far as legs and recovery go, I have no clue.

At 5300kg (IIRC) there should be not enough margin for recovery.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 03/22/2015 07:50 AM
At 5300kg (IIRC) there should be not enough margin for recovery.

well then i'd say the upgrade is pointless and useless?

Edit/CR: what Lar said re fixing your quotes!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 03/22/2015 07:52 AM
hey is this launching before jason-3 or what (and if so will it have legs)?

Schedules are always subject to change but currently most show it earlier than the July 22nd launch date for Jason-3. 

As to legs....Not at all likely, but there isn't enough public info to be 100% definitive.  Legs are only useful if they are going to attempt booster recovery.  Up to now, recovery attempts on launches sending comsats to GTO have not been possible due to the performance limitations of the rocket.  Thus making the addition of legs a needless mass penalty.  According to Elon's tweet (https://twitter.com/elonmusk/status/572257004938403840), recovery of boosters from GTO launches requires: 1. Increased thrust; 2. Subcooling LOX; 3. +10% volume on 2nd stage.  But, you should note that the tweet didn't specify for what payload masses booster recovery would then be possible.  i.e. Booster recovery on some GTO launches will be possible, but only for payloads of up to X metric tons.  We don't yet know what X will be.  But, IMHO, it is likely to be less than SES-9's mass.

Quote
well then i'd say the upgrade is pointless and useless?
  And you'd be wrong.  Don't forget that upgrading will let them launch heavier payloads! :)  A point which is relevant for this mission.  The SpaceX website currently lists the F9 performance limit for payload to GTO as 4,850kg.  With NASA's ELVperformance calculator, when using the orbital target from the ABS/Eutelsat GTO mission, the F9 was calculated as capable of lofting 4735kg.  Per Gunter's site, SES-9 will be 5330kg.  i.e. Taking the numbers at face value, the payload weighs more than the F9 is currently capable of lofting to GTO...unless there's at least some upgrade.  [Please don't anyone reply to this comment with discussion about whether or not SpaceX's numbers are sandbagged to allow for recovery, etc].

There's been lots of information out there, including statements from Elon, that this mission will feature the higher thrust performance of the M1d engines (M1d+?).  Otherwise, it hasn't seemed that they would be able to launch a payload of this size.  So, higher thrust is a given.  There's been much speculation and discussion on this site, and others, as to whether running at higher thrust also requires the subcooling/densification to substantially increase capability (as yet, I have seen no definitive public statements which could resolve that point).  So, the F9 for the SES-9 launch may or may not use subcooled LOX/RP-1.  There has also been much discussion on exactly how the 2nd stage volume increase will be achieved--2nd stage stretch vs. bulkhead shift post-densification of the LOX/prop vs. other guesses.  As yet, there have neither been any official statements as to the exact method to achieve it nor any direct comments on the expected timing of its introduction.  Depending on how involved the process is to achieve the gains, it could be as early as SES-9 or not for some time yet.

To recap, legs would only make sense if the mission will have all three of the things Elon tweeted--1. Higher thrust--check; 2. Subcooled LOX--maybe; 3. +10% vol.--maybe (IMHO less likely than #2)-- AND the increased performance allowed enough margin to recover the booster when launching a 5.3mt payload to GTO.  While I'm very doubtful that they would give enough margin for recovery, they will at least let the F9 launch a payload of this size to GTO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 03/23/2015 09:21 AM
Per Gunter's site, SES-9 will be 5330kg.  i.e. Taking the numbers at face value, the payload weighs more than the F9 is currently capable of lofting to GTO...unless there's at least some upgrade. 

But who said SpaceX committed to inject SES-9 on a GTO ?
It might be 5330kg on a sub-GTO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 03/23/2015 01:39 PM
Per Gunter's site, SES-9 will be 5330kg.  i.e. Taking the numbers at face value, the payload weighs more than the F9 is currently capable of lofting to GTO...unless there's at least some upgrade. 

But who said SpaceX committed to inject SES-9 on a GTO ?
It might be 5330kg on a sub-GTO.
I strongly suspect it will be at least GTO.  Start from the last launch, Eutelsat, which put 4168 kg into an orbit where the second burn was about 2690 m/s.  If we assume the mass goes up from 4168 to 5330, and the second stage masses 5t, then they lose about 380 m/s.  Then with ~2300 m/s from LEO, they can get to about 33,700 km, still short of GEO at 35,768 km.  So the existing Falcon would indeed be sub-GTO with about 1920 m/s to go.

You would need about 35 m/s more from the rocket to get the apogee to GTO, with no inclination change, which would yield an 1830 m/s deficit or so.

Now the bigger engines, even with no other changes, will reduce the gravity loss.  Lots of things go into this, but to a first approximation 15% greater thrust yields 15% greater acceleration, or 15% less time fighting gravity for the first stage.   If the vertical part of the flight is 100 seconds, and you can save 15 seconds from that, then you've reduced the gravity losses by 150 m/s.  This would let you get a 43,800 km apogee, or super GTO, with 1750 m/s to go.  But it would be better to reduce the inclination some rather than shoot for the highest apogee.  For the same performance you could get a 37,500 km apogee at 24.31 degrees, or 1720 m/s.

So even with no sub-cooling, and no stretch, they should be able to hit slightly super-synchronous for this mission.  And the 200 m/s of reduced satellite maneuver means 4 more years of satellite life, more or less.  Presumably that's why SES is agreeing to this.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 03/23/2015 01:49 PM
Also, if you interpret Gwynne's recent comments to mean that the upgraded F9 will put 30% more payload into GTO, multiply the ABS/Eutelsat payload mass of 4168 kg by 1.3 and you get about 5400 kg to the same orbit, which is just a tad more than the SES-9 mass. So that seems to be a reasonable interpetation of her statement.

Quote
In March 16 and 17 appearances at the Satellite 2015 conference here, Shotwell said the new-version Falcon 9, which has yet to be named, will be about 30 percent more powerful than the rocket’s current version.

http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 03/23/2015 03:03 PM
But remember one year ago :

Also by Peter B. Selding:

Quote
Peter B. de Selding ‏@pbdes 3h
SES: 'SES-9 sat to launch on SpaceX Falcon 9 will weigh ~5,330kg at launch into a sub-synchronous orbit.' Nearing rocket's capacity ceiling.
So this will be a subsynchronous mission.

Now, maybe the upgraded version will do better, but probably not granted.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 03/24/2015 02:24 AM
But remember one year ago :
Also by Peter B. Selding:
Quote
Peter B. de Selding ‏@pbdes 3h
SES: 'SES-9 sat to launch on SpaceX Falcon 9 will weigh ~5,330kg at launch into a sub-synchronous orbit.' Nearing rocket's capacity ceiling.
So this will be a subsynchronous mission.
Now, maybe the upgraded version will do better, but probably not granted.

That information is well out of date now.  If you read PBdeS' article on SES rethinking being first to fly (http://spacenews.com/ses-rethinking-being-first-to-fly-on-a-full-throttle-falcon-9) (2015-01-30) on the upgraded engines you have this:
Quote from: Peter B. de Selding
...[SES' chief technical officer] Halliwell said. “You know SpaceX is introducing into their manifest a new engine, or a modification of the current engine, with about a 20 percent increase in thrust. We’re making a decision internally as to whether we want to be the first to fly it.”
SES-9, a Boeing Space and Intelligence Systems 702-HP spacecraft expected to weigh 5,300 kilograms at launch, is near the limit of what the current Falcon 9 v1.1 vehicle can carry and was to be placed into a subsynchronous orbit. [emphasis added]
 
Which sounds to me like they originally contracted for the non-upgraded F9v1.1 to sub-GTO but have since changed to the upgraded F9 (or at least higher thrust) to GTO.  The only question then being whether they actually wanted to be first.  Something they've since decided was worth the risk. 


Per Gunter's site, SES-9 will be 5330kg.  i.e. Taking the numbers at face value, the payload weighs more than the F9 is currently capable of lofting to GTO...unless there's at least some upgrade. 
But who said SpaceX committed to inject SES-9 on a GTO? It might be 5330kg on a sub-GTO.
I think that is exactly what happened.  My original comment wasn't perfectly accurate as it did assume a GTO target.  But that isn't really relevant to the overall point I was making--even without enough margin to allow for booster recovery, the upgrades aren't pointless or useless.  They'll allow SpaceX to compete for heavier payloads on a more equal basis.  This launch would be a good case in point.  With the upgrade they'll be able to put SES-9 in a GTO instead of sub-GTO.  That's not a trivial difference to their customers.  If you read any of the analyses that LouScheffer has written in this thread, you'll see that even just the higher thrust without any of the other upgrades could potentially extend satellite operational life by a few years.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nicfit on 03/24/2015 07:59 AM
OK, I see your point, thanks for the large explanation.

2 open point on this mission then :
- GTO or sub-GTO injection
- then electrical or chemical orbit raising en route to GEO
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 03/24/2015 12:24 PM
open point on this mission then :
...[snip]...
- then electrical or chemical orbit raising en route to GEO

It's a 702HP bus with biprop for orbit raising, so there's no "or."
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 03/24/2015 04:49 PM
It could be an inclusive "or."
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 04/28/2015 07:32 PM
With Turkmensat done, pad abort in may, CRS-7 in june and JSON in July, its looking like a slow next 3 months.
Is there any info about this launch actually taking place in Q2 2015 ?
Yes, one launch / testing activity per month for LC40 is slow for SpaceX in my book.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 04/28/2015 07:57 PM
With Turkmensat done, pad abort in may, CRS-7 in june and JSON in July, its looking like a slow next 3 months.
Is there any info about this launch actually taking place in Q2 2015 ?
Yes, one launch / testing activity per month for LC40 is slow for SpaceX in my book.

This flight will almost certainly be in Q3, they still have to build and qualify the new version of the rocket.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevinof on 04/28/2015 07:59 PM
Er... what new version?  Do you mean the engine upgrade?


With Turkmensat done, pad abort in may, CRS-7 in june and JSON in July, its looking like a slow next 3 months.
Is there any info about this launch actually taking place in Q2 2015 ?
Yes, one launch / testing activity per month for LC40 is slow for SpaceX in my book.

This flight will almost certainly be in Q3, they still have to build and qualify the new version of the rocket.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 04/28/2015 08:06 PM
Er... what new version?  Do you mean the engine upgrade?


With Turkmensat done, pad abort in may, CRS-7 in june and JSON in July, its looking like a slow next 3 months.
Is there any info about this launch actually taking place in Q2 2015 ?
Yes, one launch / testing activity per month for LC40 is slow for SpaceX in my book.

This flight will almost certainly be in Q3, they still have to build and qualify the new version of the rocket.

Not just the engine thrust upgrade. The sub-cooled propellant (densification) is part of it, which probably causes some tweaks. This flight could also fly the stretched upper stage, but that is not known yet.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevinof on 04/28/2015 08:07 PM
True. Forgot about the other "bits".


Er... what new version?  Do you mean the engine upgrade?


With Turkmensat done, pad abort in may, CRS-7 in june and JSON in July, its looking like a slow next 3 months.
Is there any info about this launch actually taking place in Q2 2015 ?
Yes, one launch / testing activity per month for LC40 is slow for SpaceX in my book.

This flight will almost certainly be in Q3, they still have to build and qualify the new version of the rocket.

Not just the engine thrust upgrade. The sub-cooled propellant (densification) is part of it, which probably causes some tweaks. This flight could also fly the stretched upper stage, but that is not known yet.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/29/2015 06:05 AM
This SES press release is saying 2Q/3Q for SES 9.

http://www.ses.com/4233325/news/2015/20659801
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 04/29/2015 01:50 PM
This SES press release is saying 2Q/3Q for SES 9.

http://www.ses.com/4233325/news/2015/20659801

That's from a couple months ago.  SpaceX has said the next launch is CRS-7 on June 19 (or somewhere around there if they have to adjust cargo), Gwynne said "Summer" for the upgraded version fairly recently.  2Q does not seem realistic now.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 04/29/2015 02:32 PM
This SES press release is saying 2Q/3Q for SES 9.

http://www.ses.com/4233325/news/2015/20659801

That's from a couple months ago.  SpaceX has said the next launch is CRS-7 on June 19 (or somewhere around there if they have to adjust cargo), Gwynne said "Summer" for the upgraded version fairly recently.  2Q does not seem realistic now.
They just did a 13 day turnaround... Maybe they'll do an 11 day turnaround? ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 04/30/2015 05:30 PM
https://twitter.com/pbdes/status/593811524898131968 (https://twitter.com/pbdes/status/593811524898131968)
Tweet from @pbdes
SES: SpaceX has confirmed that our large SES-9 sat, new capacity over Asia, will launch on Falcon 9 before October.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 04/30/2015 06:17 PM
So either August before CRS-8 or 2nd half of September after CRS-8?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 05/01/2015 03:34 AM
https://twitter.com/pbdes/status/593811524898131968 (https://twitter.com/pbdes/status/593811524898131968)
Tweet from @pbdes
SES: SpaceX has confirmed that our large SES-9 sat, new capacity over Asia, will launch on Falcon 9 before October.

That's interesting.  I had assumed that they would work really hard to go before the end of June based on the financial statements reported in February:
https://twitter.com/pbdes/status/568717723552915456
Quote
SES: What a difference 1 sat makes: If SpaceX launches SES-9 in Q2, 2015-2017 CAGR is 5%. If in Q3, CAGR is 3.5%. Co has 54-sat fleet.
http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/
Quote
SES Chief Financial Officer Padraig McCarthy said during the conference call that if SES-9 is launched by June, SES’s average annual revenue between 2015 and 2017 is likely to grow by 4 percent. If the launch slips beyond June, the compound annual revenue growth will be just 3.5 percent.

I mean, June is still before October but from the wording of the new tweet it makes it sound like August or September is more the range he's taking about.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ZachS09 on 05/01/2015 08:29 PM
How about July 15? Info comes from the Rocket Launch Viewing page of www.launchphotography.com (http://www.launchphotography.com).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 05/02/2015 07:25 AM
This SES press release is saying 2Q/3Q for SES 9.

http://www.ses.com/4233325/news/2015/20659801

Just noticed, you linked to the release from February 20th.  Their 1st quarter results release from April 30th (2 days after you posted) is now saying 3Q 2015.  It's in the table close to the bottom of the document.

http://www.ses.com/4233325/news/2015/21153079

edit: parenthetical remark
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: averagespacejoe on 05/02/2015 08:00 PM
Spaceflightnow has a update showing July 15th which at a minimum is the most precise date I have seen for this yet. Although precision does not equal accuracy and everything is subject to shifts to the right.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Orbiter on 06/08/2015 12:06 AM
Spaceflightnow has a update showing July 15th which at a minimum is the most precise date I have seen for this yet. Although precision does not equal accuracy and everything is subject to shifts to the right.

Now slipped to NET August after Jason-3 per SFN.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 06/10/2015 03:55 PM
Hmmm, thought the group had settled on this satellite using standard chemical propulsion for orbit raising, but this article popped up today.  Anyone know if the site usually has good reporting?

http://advanced-television.com/2015/06/09/ses-eyes-down-look-beyond-the-top-line/ (http://advanced-television.com/2015/06/09/ses-eyes-down-look-beyond-the-top-line/)
Quote
This satellite, destined to serve Asia, already has excellent pre-sales, but because it is an all-electric satellite it will take 4-6 months to get into orbit – and only then will it start earning its keep.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/10/2015 07:38 PM
Hmmm, thought the group had settled on this satellite using standard chemical propulsion for orbit raising, but this article popped up today.  Anyone know if the site usually has good reporting?

http://advanced-television.com/2015/06/09/ses-eyes-down-look-beyond-the-top-line/ (http://advanced-television.com/2015/06/09/ses-eyes-down-look-beyond-the-top-line/)
Quote
This satellite, destined to serve Asia, already has excellent pre-sales, but because it is an all-electric satellite it will take 4-6 months to get into orbit – and only then will it start earning its keep.

The satellite is a Boeing 702HP, which has both biprop and electric propulsion:

http://boeing.mediaroom.com/2012-10-10-Boeing-to-Build-702HP-Communications-Satellite-for-SES
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sublimemarsupial on 06/17/2015 03:56 PM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rcoppola on 06/17/2015 04:02 PM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112
I love SES. They are the perfect partner to what SpaceX is trying to achieve. Good for them!

It's technically possible.  CR7 needs to return successfully and be inspected and put through a rigorous re-flight program in NM. THEN if SES-9 returns and gains qualification for re-use, then there we go. Just the fact SES is already publicly putting this out there, must cause shivers to run down the spines of the industry. I mean, how exactly do you compete against this capability and the launch deals it will provide to companies such as SES?

Edit: Forgot about Jason3, so that should be thrown in there as well. The other thing I didn't take into consideration is the fact that SES-9 is the first v1.2. So I'm not sure what results from v1.1 core re-flight testing and Qual will be applied to a V1.2 core. I would think many variances/tolerances would port over though. Regardless, all super interesting.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: e of pi on 06/17/2015 04:24 PM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112
They might have the margin to recover the first stage on that flight? SES-9 is 5.3 metric tons! I mean, that's amazing news, but I also I'm astounded it's technically feasible.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/17/2015 04:39 PM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112
They might have the margin to recover the first stage on that flight? SES-9 is 5.3 metric tons! I mean, that's amazing news, but I also I'm astounded it's technically feasible.

If it is, then this opens up some interesting possibilities for SpaceX and tightens the screws on the competition significantly.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 06/17/2015 04:56 PM
We've known for a while now that the purpose of the "1.2" upgrades are to enable barge recovery of GTO flights.  This is admittedly a heavier payload than I had been imagining in such a scenario.

It almost seems to me that SES is pressuring SpaceX here as well, in terms of trying to establish a lower price for a reflows core.  Regardless, it is great to see this kind of discussion taking place.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/17/2015 05:23 PM
So will Boeing and Airbus respond by discounting satellite manufacturing if the client uses their (ULA's and Ariene's) LV? In fact maybe they already do.

Once SpaceX has a handle on their own constellation will they start building satellites for clients?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 06/17/2015 05:28 PM
So will Boeing and Airbus respond by discounting satellite manufacturing if the client uses their (ULA's and Ariene's) LV? In fact maybe they already do.


No, Boeing can not do that.  That is not allowed per FTC.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: davey142 on 06/17/2015 05:57 PM
So will Boeing and Airbus respond by discounting satellite manufacturing if the client uses their (ULA's and Ariene's) LV? In fact maybe they already do.

Once SpaceX has a handle on their own constellation will they start building satellites for clients?
If anything, Boeing is actually helping SpaceX with their 702sp satellites.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 06/17/2015 06:12 PM
Here's one SpaceX employee's view on the SES request:

Quote
@mattsachtler: This is one of the most exciting things I've heard in a long time. Customers legit interested in reflight is huge. https://t.co/x7XBGfaAOa

https://twitter.com/mattsachtler/status/611220126528991232 (https://twitter.com/mattsachtler/status/611220126528991232)

I agree.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CJ on 06/17/2015 06:43 PM
I'm very, very intrigued by SES having a interest in doing this (flying on a recovered core). It does not surprise me per se, because they have clear motive ($$$), but I'm shocked to see them express such interest before the first recovered core has been examined. This is a huge vote of confidence for SpaceX, and IMHO great news.   

However... I'd be willing to bet that SES would not want their launch to be the first-ever relfight of a recovered core. I'd bet they'd want to see a test relight of one first, even if it's just a grasshopper-style hop.   

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/17/2015 06:53 PM
I'm very, very intrigued by SES having a interest in doing this (flying on a recovered core). It does not surprise me per se, because they have clear motive ($$$), but I'm shocked to see them express such interest before the first recovered core has been examined. This is a huge vote of confidence for SpaceX, and IMHO great news.   

However... I'd be willing to bet that SES would not want their launch to be the first-ever relfight of a recovered core. I'd bet they'd want to see a test relight of one first, even if it's just a grasshopper-style hop.

Aren't they going first with the higher thurst Merlin's and densified propellant?

Also, I think that tweet was a prelude towards playing up how awesome they are to participate in being the first to put a payload on a reflown core.  Someone has to be first, SES certainly has been a good customer so far, they are getting some sorts of breaks from SpaceX for doing all this, SpaceX is getting a lot from them, this tweet is a net benefit to SpaceX too (presuming that recovery is working).  A lot is riding on the Crs/Spx-7 recovery now. Though maybe if there were still issues the Jason 3 core could still save the day.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: friendly3 on 06/17/2015 07:49 PM
However... I'd be willing to bet that SES would not want their launch to be the first-ever relfight of a recovered core. I'd bet they'd want to see a test relight of one first, even if it's just a grasshopper-style hop.

Why? SES was the first to launch a GTO sat on a Falcon 9 (SES-8) and they will also be the first to use the 1.2 version.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 06/17/2015 08:44 PM
SpaceX is going to be testing the first reused stage a lot anyway. Launch failures for paying customers are definitely not in SpaceX's interests.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/17/2015 10:54 PM
SpaceX is going to be testing the first reused stage a lot anyway. Launch failures for paying customers are definitely not in SpaceX's interests.

However SES-10 is scheduled for a year from now. Plenty of time to test the first recovered core a lot. By the time SES-10 is ready to go I bet they have recovered 8 more cores after the first.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 06/17/2015 11:43 PM
Reusable doesn't have to be about just cost of a launch. Think about jumping ahead in the manifest by something like a year.

If you're SES you could beat your rivals to on orbit services and dominate in speed to fulfillment. Gets even better if you get 3-6x out of a first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: TrevorMonty on 06/18/2015 03:30 AM
Reusable doesn't have to be about just cost of a launch. Think about jumping ahead in the manifest by something like a year.

If you're SES you could beat your rivals to on orbit services and dominate in speed to fulfillment. Gets even better if you get 3-6x out of a first stage.
That is one of selling points of reuse, shorter lead times.

If there was a recovered booster available today, some of Proton's customers would seriously consider it , especially if they could fly in next few months.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 06/18/2015 03:44 AM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112

I guess I need to revise my assumptions.  Earlier in the tread I had argued that SpaceX was unlikely to recover the booster for this mission because I assumed that to do so for a 5.3 tonne, GTO comsat would require all 3 of the upgrades that make the "v1.2".  At the time, the only statements were that SpaceX would use the higher thrust, M1D+ engines.  I thought that they would likely also use LOX/RP-1 subchilling but that the expanded volume upper stage wouldn't be fielded at that time.  Ergo, no recovery as I assumed all 3 would be needed.  One of those assumptions was wrong.  Either that the expanded volume US wouldn't be used or that all 3 changes were necessary to allow recovery given this mission's requirements.  Interesting.  Currently, I'm inclined to bet that it's the volume expansion.

Also, the tweet suggests an interesting paradigm for re-use and one that I haven't seen canvassed in this forum.  That successful recovery could have effects on launch prices has been well covered, but not the idea that a payload company like SES might "reserve" the rights to first use of a specific core.  Sort of like a direct amortization of part of the rockets used in their launches.  I wonder if this is just spit-balling or something SpaceX has considered.  Or is it just SES trying to negotiate "the right to recover" on their SES-9 launch for a cheaper future launch?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/18/2015 03:54 AM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112

I guess I need to revise my assumptions.  Earlier in the tread I had argued that SpaceX was unlikely to recover the booster for this mission because I assumed that to do so for a 5.3 tonne, GTO comsat would require all 3 of the upgrades that make the "v1.2".  At the time, the only statements were that SpaceX would use the higher thrust, M1D+ engines.  I thought that they would likely also use LOX/RP-1 subchilling but that the expanded volume upper stage wouldn't be fielded at that time.  Ergo, no recovery as I assumed all 3 would be needed.  One of those assumptions was wrong.  Either that the expanded volume US wouldn't be used or that all 3 changes were necessary to allow recovery given this mission's requirements.  Interesting.  Currently, I'm inclined to bet that it's the volume expansion.

Also, the tweet suggests an interesting paradigm for re-use and one that I haven't seen canvassed in this forum.  That successful recovery could have effects on launch prices has been well covered, but not the idea that a payload company like SES might "reserve" the rights to first use of a specific core.  Sort of like a direct amortization of part of the rockets used in their launches.  I wonder if this is just spit-balling or something SpaceX has considered.  Or is it just SES trying to negotiate "the right to recover" on their SES-9 launch for a cheaper future launch?

My opinion, and worth the amortized value of the pixels as portion of your screen real estate for the time it takes you to read my opinion, is that this was a rather carefully considered comment that was tweeted 'after' the subject was broached and calculated to make both companies look good.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: PhaseMage on 06/18/2015 06:17 AM
Maybe if they insert into a lower orbit, they can still recover the core, even without all the 1.2 enhancements? This would then take SES-9 longer to get on station, and the cost for that could be offset with a negotiation for cheaper reflight of the reused core.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 06/18/2015 07:54 AM
Maybe if they insert into a lower orbit, they can still recover the core, even without all the 1.2 enhancements? This would then take SES-9 longer to get on station, and the cost for that could be offset with a negotiation for cheaper reflight of the reused core.
News coverage has already said that SES-9 is a hybrid that will use SEP for station keeping and some of the orbit insertion but that part of that initial impulse would come from a chemical engine.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: aga on 06/18/2015 11:30 AM
They might have the margin to recover the first stage on that flight? SES-9 is 5.3 metric tons! I mean, that's amazing news, but I also I'm astounded it's technically feasible.

iirc, ses-9 is not going to the standard GTO... just to some sub-GTO... or?

does anyone have the target orbit?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mader Levap on 06/18/2015 01:04 PM
My opinion, and worth the amortized value of the pixels as portion of your screen real estate for the time it takes you to read my opinion, is that this was a rather carefully considered comment that was tweeted 'after' the subject was broached and calculated to make both companies look good.
IMO it was done by SES as pressure on other launch providers to take whole "reusable rockets" thing more seriously than ever.

This is why they issued this statement so early in game. I doubt they actually think they can get this particular core for relaunch again.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/18/2015 01:35 PM
I doubt they actually think they can get this particular core for relaunch again.

Why not?

It's possible that CRS-7 or Jason-3 will be the first recovered stage, which will go through the most rigorous teardown, inspection, multiple reflight, etc. If that stage validates multiple reflights, it opens the door to reflying future stages like SES-9 without the extensive teardown, etc. In which case the SES-9 S1 could be available for commercial reflight.

So another interpretation is that SES believes CRS-7 or Jason-3  S1 will be recovered and shown to be good for multiple reflights, and they feel that the differences between v1.1 and 1.2 are minor enough that those v1.1 S1 reflights will give them good confidence in reflying the SES-9 S1 even though it's a v1.2, and they are starting the discussion with SpaceX to explore that possibility as a real option.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 06/18/2015 02:19 PM
I agree with everything @kabloona said, *plus* "and SES sees this as a financial opportunity".  Either to get an excellent price in exchange for being first, or as part of a package with other risks they are accepting as part of SES-9, or simply to get an earlier launch slot (if all other "new" cores from Hawthorne are spoken for).  This is a possible win-win for both sides.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 06/18/2015 03:04 PM
From pbdes on twitter, this launch will be recovering the first stage of F9:

"SES CTO: We've asked SpaceX if recovered 1st stage from our SES-9 launch this summer could be sold to us for lower-cost future launch. TBD."

https://twitter.com/pbdes/status/611199719864410112 (https://twitter.com/pbdes/status/611199719864410112)

This seems to be the ultimate extension of the "collectible commenerative glass" marketing campaigns:

Buy the launch with our special, reuseable rocket , keep the empty first stage!

Of course, it's not really SpaceX who is suggesting it.  It's more like offering the hostess at a restaraunt a big tip to let you take home the place settings after your meal. 

It's kind of strange.  What would SES do with a first stage?  They would have to hire SpaceX to launch it again.  It would seem to be suggesting an entirely different business model to SpaceX, one that would give "launch services" a new meaning.  It doesn't seem practical, but perhaps people with more direct experience can see how this could be arranged. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mader Levap on 06/18/2015 03:12 PM
It's possible that CRS-7 or Jason-3 will be the first recovered stage, which will go through the most rigorous teardown, inspection, multiple reflight, etc. If that stage validates multiple reflights, it opens the door to reflying future stages like SES-9 without the extensive teardown, etc. In which case the SES-9 S1 could be available for commercial reflight.

It is very big if. I assume some significant changes* will be needed. See ya in 2017 - this is my bet on date of first actual relaunch.

* Defined as something that will require extensive modification or production of new bath of cores with everything that implies - retesting, requalification etc.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/18/2015 03:49 PM
It's kind of strange.  What would SES do with a first stage?  They would have to hire SpaceX to launch it again.  It would seem to be suggesting an entirely different business model to SpaceX, one that would give "launch services" a new meaning.  It doesn't seem practical, but perhaps people with more direct experience can see how this could be arranged.

I wouldn't take that too literally. It's Twitter shorthand for buying a launch service using the previously-flown stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 06/18/2015 09:17 PM
It's kind of strange.  What would SES do with a first stage?  They would have to hire SpaceX to launch it again.  It would seem to be suggesting an entirely different business model to SpaceX, one that would give "launch services" a new meaning.  It doesn't seem practical, but perhaps people with more direct experience can see how this could be arranged.

I wouldn't take that too literally. It's Twitter shorthand for buying a launch service using the previously-flown stage.

So maybe I didn't need help from someone with more experiences in rockets, just more experience interpreting Twitter.  :P 
That makes sense.  Thanks
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: TrevorMonty on 06/18/2015 10:38 PM
Here is Spacenews article on this subject.

http://spacenews.com/spacex-early-adopter-ses-ready-to-reuse-falcon-9-%c2%ad-for-the-right-price/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: laika_fr on 06/18/2015 11:27 PM
This is relatively new so, they keep a "what our customers say" approach same goes with the FH "board" hosting Viasat.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/19/2015 01:29 AM
It's possible that CRS-7 or Jason-3 will be the first recovered stage, which will go through the most rigorous teardown, inspection, multiple reflight, etc. If that stage validates multiple reflights, it opens the door to reflying future stages like SES-9 without the extensive teardown, etc. In which case the SES-9 S1 could be available for commercial reflight.

It is very big if. I assume some significant changes* will be needed. See ya in 2017 - this is my bet on date of first actual relaunch.

* Defined as something that will require extensive modification or production of new bath of cores with everything that implies - retesting, requalification etc.

SES can afford to be patient. They'll be launching satellites on F9's for a long time to come. The used stage can sit in the barn for a year or two if necessary while SpaceX works the kinks out of reuse on other stages (CRS-7, Jason-3). If it saves SES $20 million or so, it's worth the wait.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Garrett on 06/19/2015 08:22 AM
SpaceX will probably be more than happy to have SES as a customer on a reused first stage flight. But I would doubt that they would sell or reserve a specific first stage used on one SES flight for a future SES flight. SpaceX is a launch services provider, not a rocket vendor, so they will likely decide internally, based on various factors (e.g. optimum processing flow, viability of stage reuse, etc.) which stages get reused on which flights.
They'll probably just have to find a nice way to tell their customer that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/19/2015 11:47 AM
SpaceX will probably be more than happy to have SES as a customer on a reused first stage flight. But I would doubt that they would sell or reserve a specific first stage used on one SES flight for a future SES flight. SpaceX is a launch services provider, not a rocket vendor, so they will likely decide internally, based on various factors (e.g. optimum processing flow, viability of stage reuse, etc.) which stages get reused on which flights.
They'll probably just have to find a nice way to tell their customer that.

They're introducing a new untried product (used rockets) that some customers may be hesitant to purchase until someone else takes the risk first and survives the attempt. For SpaceX to sign up a willing customer to be that first risk-taker, or one of the first few, they may be willing to make some special accommodations.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 06/19/2015 01:10 PM
SpaceX will probably be more than happy to have SES as a customer on a reused first stage flight. But I would doubt that they would sell or reserve a specific first stage used on one SES flight for a future SES flight. SpaceX is a launch services provider, not a rocket vendor, so they will likely decide internally, based on various factors (e.g. optimum processing flow, viability of stage reuse, etc.) which stages get reused on which flights.
They'll probably just have to find a nice way to tell their customer that.
Again, I think the specificity of the request was just twitter-speak.  I wouldn't read too much into it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MTom on 06/22/2015 06:25 PM
Could SES buy a lower cost satellite too?
E.g. prototype or legacy or something else?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 06/23/2015 12:57 AM
SES can afford to be patient. They'll be launching satellites on F9's for a long time to come. The used stage can sit in the barn for a year or two if necessary while SpaceX works the kinks out of reuse on other stages (CRS-7, Jason-3). If it saves SES $20 million or so, it's worth the wait.

If SpaceX get a core back it won't be 1-2 years before it flies again.  6 months maybe for the first one.  It doesn't service the purpose if they have to spend money on it for that long checking it out and servicing it.



Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JBF on 06/23/2015 01:06 AM
SES can afford to be patient. They'll be launching satellites on F9's for a long time to come. The used stage can sit in the barn for a year or two if necessary while SpaceX works the kinks out of reuse on other stages (CRS-7, Jason-3). If it saves SES $20 million or so, it's worth the wait.

If SpaceX get a core back it won't be 1-2 years before it flies again.  6 months maybe for the first one.  It doesn't service the purpose if they have to spend money on it for that long checking it out and servicing it.

In my opinion unless they are going for the publicity stunt the 1st core they recover will never fly again.  It will be dissembled and go though detailed structural analysis.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 06/23/2015 03:44 AM
I find it amusing that folks assume this has to be all-or-nothing.

Just like Dragon is *already doing*, some components will immediately be reused, and some will be replaced.  The first "reused" stage will be whatever mix of old and new makes the most sense.

Eventually we'll get a reflight of an (almost-) entirely "old" stage, but it can/will be an incremental process.  The goal is to lower costs/improve component robustness/learn about reuse/etc.  Nobody needs to do anything absolute just to make a point.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 06/23/2015 01:30 PM
I thought the first recovered stage is going to New Mexico for testing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 06/23/2015 01:32 PM
In my opinion unless they are going for the publicity stunt the 1st core they recover will never fly again.  It will be dissembled and go though detailed structural analysis.

IIRC we have already heard that the 1st recovered core will go to Spaceport America in NM for a grasshopper-like test campaign, and the 2nd recovered core will be used for qualification testing.  Obviously they would have to check them out first and they might find something to derail those plans.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 06/23/2015 02:03 PM
IIRC we have already heard that the 1st recovered core will go to Spaceport America in NM for a grasshopper-like test campaign, and the 2nd recovered core will be used for qualification testing.  Obviously they would have to check them out first and they might find something to derail those plans.

Yes, in this article.

http://www.nasaspaceflight.com/2015/03/spaceport-america-spacex-reusability-testing/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 06/24/2015 02:50 PM
IIRC we have already heard that the 1st recovered core will go to Spaceport America in NM for a grasshopper-like test campaign, and the 2nd recovered core will be used for qualification testing.  Obviously they would have to check them out first and they might find something to derail those plans.

Yes, in this article.

http://www.nasaspaceflight.com/2015/03/spaceport-america-spacex-reusability-testing/

Following up on my earlier message above:

The first successful stage to be recovered will head to New Mexico, although I don't understand what testing is needed there once they've demonstrated successful recovery. 

Any core that SES reuses would be a v1.2 and not the v1.1 in use this weekend. SpaceX is almost finished with the v1.1 and they aren't going to keep a mixed portfolio of cores. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 06/24/2015 03:03 PM
The first successful stage to be recovered will head to New Mexico, although I don't understand what testing is needed there once they've demonstrated successful recovery. 

The stage will be tested to limits.
So far SpaceX has not recovered a returned first stage intact. SpaceX has no exact idea just how much 'wear-and-tear' a returned stage has suffered. The testing at New Mexico is partially designed to find out how much more a returned stage can take before it fails. To what extent is a returned stage suited to be launched again on an orbital mission? To what extent does a returned stage require refurbishment before re-flight? How often can stages be re-flown before they need to be retired? All those questions are behind the test program in New Mexico.
IMO it is safe to assume that not one, but at least several returned stages will be tested in New Mexico to give SpaceX insight into the extent of reusability of the Falcon 9 v1.1/v1.1-upgraded first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 06/24/2015 03:22 PM
SpaceX does, in fact, have some idea of the wear and tear involved. Telemetry and recovered pieces of the rocket as well as grasshopper and F9Rdev1 tests. Not to mention the extensive ground testing of their stages.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rcoppola on 06/24/2015 03:54 PM
I agree w & R.

A few more things that will need to be baselined as they try to find the tolerances for re-used stages during NM re-flight tests.

-V1.2 stages will have different thrust and fuel vectors that will apply alternate stresses to the stages then V1.1.

-2nd stage stretch with additional fuel mass will also impact structural core stage compressions which will also impact "wear & tear" and subsequent re-use

-V1.2 will be launching larger payloads to more orbits. While not all F9s will be tasked with this, there will be additional flight profiles which will cause harsher return profiles that will need to be checked as well.

So, these next two returns are critical but IMO, SES-9 and its' subsequent return, inspection and re-test will really validate, their ultimate re-use guidelines. (so-to-speak)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AndyX on 09/07/2015 01:16 PM
Cross posting on request!

http://www.nasaspaceflight.com/2015/09/spacex-conducts-falcon-9-improvements-busy-schedule/

Notes:
Summary of some of the notes we've been working with in L2.
Schedule is highly preliminary, but confidence in it was elevated by other sites later noting they think SES-9 will ride first as RTF and the closeness of the CRS-8 date. Still totally preliminary - don't go booking any flights! ;)

A lot of media ran with Ms. Shotwell's comments from AIAA, so tried to avoid copying that as you will already have read it.

A bit of cool stuff on the Dragons and some things you may not have heard about per the "Deep Dive" work and alternative path evaluations (one of which we think caused one journalist to think the struts weren't at fault. That one took a good bit of evaluation to show it was only a check on the fault tree, not a smoking gun, so I can see how that could have been misinterpreted by that other site).

Could have gone on a bit about 2016 with FH, but didn't want to get too wordy and kept it below 1500 words. We'll do something on FH later (probably for a milestone such as pad complete - which it nearly is, or a core shipping, etc.) Same goes with ASDS and Vandy first stage landings.

Please copy this post (all of the post) into the relevant manifest and mission threads, so people have the link and also my note about not booking hotels just yet! ;D) Just thought it would be a good idea to have a standalone thread, otherwise we may end up with people talking about future Dragons in a Jason-3 thread, etc.

Hope this is useful to you all.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 09/08/2015 03:05 AM
C'mon guys... Plans change.
Reuse is a massive wildcard.
Until SX recovers the first stage, even for SX itself its speculation on what they will do next. Whatever they say might (heck, probably will) be altered.
  The stage might be in better or worse state than expected.

There's significant precedent for this. Early re-use tests progressed so much faster than expected it made the GH program mosty obsolete. They quickly changed their focus into the landing aspects of GH, as they managed the soft landing on the ocean prematurely.

Let's not go too wild on this debate.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Confusador on 09/08/2015 03:26 PM
C'mon guys... Plans change.
Reuse is a massive wildcard.
Until SX recovers the first stage, even for SX itself its speculation on what they will do next. Whatever they say might (heck, probably will) be altered.
  The stage might be in better or worse state than expected.

There's significant precedent for this. Early re-use tests progressed so much faster than expected it made the GH program mosty obsolete. They quickly changed their focus into the landing aspects of GH, as they managed the soft landing on the ocean prematurely.

Let's not go too wild on this debate.

Seeing as that discussion hadn't continued since June, I'd say no one was going wild.  Of course, knowing this forum they will now, but you have only yourself to blame. ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: NX-0 on 09/10/2015 02:54 PM
Did I read this will be a v1.2 and not a v1.1?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 09/10/2015 03:56 PM
Did I read this will be a v1.2 and not a v1.1?
Yes
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevin-rf on 09/10/2015 04:29 PM
Thread title lists v1.1, someone should sacrifice a virgin to the mods ...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 09/10/2015 04:43 PM
Done....the thread title that is ;)

PS Update 2 for the launch date plans:
http://www.nasaspaceflight.com/2015/09/full-thrust-falcon-9-stage-testing-mcgregor/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 09/14/2015 08:00 PM
Seems to be settling in the middle of Nov.

Nov 1. Then Nov. 20. SES hoping for Nov. 17.

And yeah, we're still waiting for that short firing. Was to be last week, but they had a few teething issues with ths new test stand.

Peter B. de Selding ‏@pbdes  2m2 minutes ago
SES: No earlier than Nov 17 for SpaceX Falcon 9 v1 upgrade flight of SES-9. 15-second ignition of denser-fueled 1st stage this week.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Eagandale4114 on 10/09/2015 06:52 PM
We are getting closer! Here is the fcc application.
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=67983
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 10/09/2015 09:34 PM
We are getting closer! Here is the fcc application.
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=67983

Looks like they have invented time travel:

Quote
Requested Period of Operation
Operation Start Date:   11/15/2015
Operation End Date:   05/15/2015

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mangala on 10/10/2015 10:54 AM


Looks like they have invented time travel:

Quote
Requested Period of Operation
Operation Start Date:   11/15/2015
Operation End Date:   05/15/2015

So Chris was right about that:
Chris B - NSF
‏@NASASpaceflight

Tease: It may take weeks, or even months, to be announced, but what I've just been shown is THE most exciting thing EVER. #SpaceX


 ;D ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: jacqmans on 10/21/2015 11:00 AM
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: chapi on 10/21/2015 01:54 PM

Which is the facility the satellite is standing right now (I mean, on those pictures)?

Thanks

Edit : removed a silly question
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 10/21/2015 03:04 PM
the factory
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Semmel on 10/21/2015 06:42 PM
Must be scary to handle that equipment. Especially when the scaffolding comes off. I have seen some pretty scary expensive scientific instruments close up. I was sweating bricks and kept my hands tight in their pockets, never going to touch anything. I cant imagine how handling a satellite must be. Good luck folks! :)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Skyrocket on 10/21/2015 07:24 PM
Must be scary to handle that equipment. Especially when the scaffolding comes off. I have seen some pretty scary expensive scientific instruments close up. I was sweating bricks and kept my hands tight in their pockets, never going to touch anything. I cant imagine how handling a satellite must be. Good luck folks! :)

Even though there have been accidents, when people became too careless while handling these multi-million dollar satellites. You really do not want to cause such a mishap like the NOAA-N-Prime incident: http://www.spaceref.com/news/viewsr.html?pid=10299
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: NovaSilisko on 10/21/2015 07:54 PM
Must be scary to handle that equipment. Especially when the scaffolding comes off. I have seen some pretty scary expensive scientific instruments close up. I was sweating bricks and kept my hands tight in their pockets, never going to touch anything. I cant imagine how handling a satellite must be. Good luck folks! :)

Even though there have been accidents, when people became too careless while handling these multi-million dollar satellites. You really do not want to cause such a mishap like the NOAA-N-Prime incident: http://www.spaceref.com/news/viewsr.html?pid=10299

A partial non sequitor perhaps, but a thread I started a while back yielded a lot of good recollections of similar incidents http://forum.nasaspaceflight.com/index.php?topic=34926
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Graham on 12/10/2015 04:07 PM
Peter de Sleding reports that SES expects their sat to go uphill on a FT in mid January
Quote
SES: We now expect our SES-9 (5,300kg-important-for-2016-rev-forecast) satellite to launch on SpaceX Full-Thrust Falcon 9 in mid-January.

And James Dean reports that the sat itself is at the Cape
Quote
SES reports its SES-9 communications satellite has arrived at Cape Canaveral for mid-January launch to GEO on upgraded SpaceX Falcon 9.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Sesquipedalian on 12/10/2015 04:40 PM
I wonder if it swapped with CRS-8.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 12/10/2015 05:29 PM
Yep, this one is Jan. Updated the title.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: pericynthion on 12/22/2015 02:06 AM
Anybody know whether the upgraded F9 has the performance for the first stage to RTLS on this flight, or whether it will have to be a barge landing?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 12/22/2015 08:51 AM
I don't know for sure, but this is is a much heavier payload into a higher delta-V orbit. I would expect that a barge at sea would be required.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 12/22/2015 10:32 AM
Proposed Party Thread title for SES-9: "Two Up, Two Down".
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jarnis on 12/22/2015 10:55 AM
Proposed Party Thread title for SES-9: "Two Up, Two Down".

SES-9: "The Drone Ship Returns" or "Back On The Drone Ship".

(a fairly safe bet that it'll land on barge)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 12/22/2015 11:07 AM
Proposed Party Thread title for SES-9: "Two Up, Two Down".

SES-9: "The Drone Ship Returns" or "Back On The Drone Ship".

(a fairly safe bet that it'll land on barge)

I'd suggest "The Drone Ship Awakens" given the other space-related phenomenon happening now.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rocx on 12/22/2015 11:25 AM
Given that it is a sequel: The Drone Ship Strikes Back!

Or given the great faith that SES has always had in SpaceX's capabilities: Full trust in Full Thrust
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mtakala24 on 12/22/2015 11:31 AM
"Philae awakes for this one too!"
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 12/22/2015 11:57 AM
"One more just like before"
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 12/22/2015 12:05 PM
Has it been announced this will be a landing at all? SES-9 has a mass of 5,330 kg.  If my guesses above are correct, even with a barge landing the limit for recoverable GTO would be somewhere in the low 4000s.  I'd love to be proven wrong, though. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cdleonard on 12/22/2015 12:08 PM
SES-9: "The Drone Ship Returns"

If all goes well this will be the third booster to be recovered and the first one with a chance of flying again. SES has also said that they would be very interested in being the first to fly on a reused booster.

This means it's possible that SES-10 (currently scheduled for second half of 2016) will use the same booster as SES-9. "The Booster Returns".
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: aga on 12/22/2015 04:13 PM
please stop it... first create a party thread and then suggest names for it in that thread... some of the people here are not interested in the party thread spam...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 12/22/2015 04:20 PM
I don't know for sure, but this is is a much heavier payload into a higher delta-V orbit. I would expect that a barge at sea would be required.

This is almost the perfect combination of payload and orbit to see where the cut-off lies.  If RTLS, then we know the claim of FT's capability is valid.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 12/22/2015 04:35 PM
This is almost the perfect combination of payload and orbit to see where the cut-off lies.  If RTLS, then we know the claim of FT's capability is valid.
At 5.3 tons, this is much too heavy for RTLS unless SpaceX has really sandbagged the numbers.  This would have been an expendable flight on a 1.1.

Will be a barge landing, for sure.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: saliva_sweet on 12/22/2015 04:43 PM
Has it been announced this will be a landing at all? SES-9 has a mass of 5,330 kg.  If my guesses above are correct, even with a barge landing the limit for recoverable GTO would be somewhere in the low 4000s.  I'd love to be proven wrong, though.

I recall that a recovery attempt was confirmed by SES, but I suspect the orbit is likely to stretch the traditional meaning of GTO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 12/22/2015 04:55 PM
This is almost the perfect combination of payload and orbit to see where the cut-off lies.  If RTLS, then we know the claim of FT's capability is valid.
At 5.3 tons, this is much too heavy for RTLS unless SpaceX has really sandbagged the numbers.  This would have been an expendable flight on a 1.1.

Will be a barge landing, for sure.

Has it been announced this will be a landing at all? SES-9 has a mass of 5,330 kg.  If my guesses above are correct, even with a barge landing the limit for recoverable GTO would be somewhere in the low 4000s.  I'd love to be proven wrong, though.

Since our estimates are all over the map, this flight should inform us of FT capability.

Recoverable after lofting 5,330mT -- likely, but some skepticism.
Barge needed or RTLS -- we'll see.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: su27k on 12/22/2015 06:29 PM
Has it been announced this will be a landing at all? SES-9 has a mass of 5,330 kg.  If my guesses above are correct, even with a barge landing the limit for recoverable GTO would be somewhere in the low 4000s.  I'd love to be proven wrong, though.

I recall that a recovery attempt was confirmed by SES, but I suspect the orbit is likely to stretch the traditional meaning of GTO.

On the first page of this thread you can see the original plan is for launch to go to a sub-synchronous orbit. I do wonder if SpaceX would be willing to give up recovery in order to put the satellite closer to GTO, as a compensation for the delays.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 12/22/2015 06:34 PM
I guess I'll just have to try to act surprised when the SES-9 launch is to ~ -1800m/s of GSO (or slightly sub that) with downrange barge landing...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rocx on 12/22/2015 06:39 PM
An update about the expected launch date from this article: http://spacenews.com/falcon-9s-second-stage-restart-was-just-as-important-as-sticking-the-landing/
Quote
SES on Dec. 22 said all the information it had from the launch reinforced its plans to launch SES-9 by late January aboard the upgraded Falcon 9.

That pretty much confirms that this one will launch after Jason, save for unlikely payload delays.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 12/22/2015 08:44 PM
Given Musk's numbers from last night, we can make some better guesses.  His figure for a barge recovery is 8000 km/hour at staging, or 2220 m/s.  The second stage has to get to LEO (7.79 km/sec) plus inject to GTO (about 2.34 km/sec for a 1800 m/s deficit, or 2.70 km/sec for a 1500 m/s deficit).  Plus there are still gravity losses to overcome - these should be on the order of 200-400 m/s.  I'll guess 300 for this calculation, and subtract from the booster velocity.

So for the 1800 m/s deficit:
 7.79 LEO
 2.34 GTO injection
-1.92 booster injection
-------
8.21 km/sec from the second stage.  With the bigger nozzle, this has an ISP of 348.  So the mass ratio needed is exp (8210/(348*9.8 )) or about 11.1.   Assume the second stage masses 125 tonnes, and drops the fairing right away.  The fairing is known to be heavy, so call it 4 tonnes for a starting mass of 121 tonnes.  Then the ending mass must be 121/11.1 = 10.90 tonnes.  The satellite is 5.33 so everything else - second stage, residuals, payload adapter - must mass 5.57 tonnes.  This seems in line with what folks have estimated before, plus a few hundred kg  for the second stage stretch.

Trying to hit a 1500 m/s deficit seems harder.  You now need 8.57 km/sec from the second stage.  This makes the mass ratio 12.37, for an ending mass of 9.78 t.  This is only 4.45 t for the second stage, residuals, and adapter.  This seems low to me, though only SpaceX knows for sure.

We can also form a pretty good guess of what barge recovery costs in terms of delta-V.  The rocket used to hold 396 t of fuel.  Now say it's 420t, a 6% improvement.  The empty stage + legs is guessed at about 30t, and the fuel needed for a (non-return) landing is also about 30 t (this is full thrust on 3 engines for 30 seconds for the retro burn, then 30 seconds on one engine for the landing burn).  Thus the theoretical no-recovery delta-V is 311*9.8*ln((420+30+125)/(30+125)) = 3995 m/s.  With recovery, the final mass is 30 t more, so the delta V is 3456 m/s.   So making the reasonable assumption that the lower atmosphere ISP, drag, and gravity losses are similar, we find that barge recovery costs about 540 m/s.   

For a satellite of SES-9 size, or maybe a little bigger, this could lead to an interesting calculation.  SpaceX could offer a 1500 m/s deficit expendable, or  a 1800 m/s recoverable.  Depending on the cost delta, the customer could decide.

Alternatively, it would seem SpaceX could launch about 1.5 tonnes more into the same GTO orbit using an expendable vs a recoverable rocket.  So on the very high end of the mass spectrum, they might be able to put a 7 t comsat into an 1800 m/s deficit with an expendable rocket.  This is about as big as comsats get.  The question would be if customers are willing to accept the increased deficit for a (presumably) lower cost.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Roy_H on 12/25/2015 07:29 PM
... see above

Interesting analysis, thanks. I think this shows the importance of barge landing. This is much harder than RTLS and SpaceX must succeed at sea landings to make their recovery ratio high.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 12/26/2015 05:17 PM
... see above

Interesting analysis, thanks. I think this shows the importance of barge landing. This is much harder than RTLS and SpaceX must succeed at sea landings to make their recovery ratio high.
Yes, landing is easier than barging ("sea landing" is a misnomer, so use the neologism "barging"), but their precision is high enough that I really don't think it's a serious problem. I believe we've seen the most annoying things with bargings already addressed with more powerful station-keeping thrusters, etc.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 12/26/2015 05:22 PM
A "problem" with barging is that there is a bigger chance of the weather dictating the success or not. Especially for FH central core in a high energy mission (where the barge is far out in the ocean).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: modemeagle on 12/26/2015 06:21 PM
I updated my simulation for F9 Full Thrust based on as much information I could find and calibrated it simulating the ORBCOMM-2 launch.  Here is my simulation for SES-9 with SI ASDS recovery.  I simulated a direct 200X35788 orbit so that I would not need to simulate the coast phase and 2nd burn.  The end result of residual SII propellant is going to be a little higher doing it this way since there will be some loss during the coast.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Roy_H on 12/26/2015 08:40 PM
@modemegle, Thank you for your excellent graphics. But I do not understand fully, so horizontal for most graphs is in seconds. The graph labeled "Angle of Attack" I assume is for first stage only, and I thought it would go through a full 90° instead of the maximum 15° shown. And if it is not asking too much, on the last graph showing the Range/Altitude could a second line showing the path of the first stage landing be added?
Edit: Am I correct in assuming the first stage would have only re-entry and landing burns, no boost-back burn?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: modemeagle on 12/26/2015 09:23 PM
@modemegle, Thank you for your excellent graphics. But I do not understand fully, so horizontal for most graphs is in seconds. The graph labeled "Angle of Attack" I assume is for first stage only, and I thought it would go through a full 90° instead of the maximum 15° shown. And if it is not asking too much, on the last graph showing the Range/Altitude could a second line showing the path of the first stage landing be added?
Edit: Am I correct in assuming the first stage would have only re-entry and landing burns, no boost-back burn?

Roy_H,
This is just the launch with SI and SII burn and does not cover the actual boost back of SI.  It is time consuming to model that since it is manual input at each stage.  I used the 5000 km/h and 8000 km/h to model RTLS and ASDS landings that Elon spoke about.  Easier for me to model considering the last time I modeled boost back I had to model each iteration manually until I found a combination that got the payload to orbit and the SI back on the ground at the landing site.

I would also expect them to use the 3 burns doing an ASDS landing.  The stage has a horizontal velocity close to 2km/s which I would expect it to be too much when it hits the atmosphere without some braking.  My simulations of boost back had the horizontal velocity around 600m/s at atmospheric entry.  This is all just a guess though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 12/26/2015 09:44 PM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 12/26/2015 10:01 PM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?

was the middle burn to create a cushion for the rocket as it hits the thicker atmosphere?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mongo62 on 12/26/2015 10:20 PM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?

was the middle burn to create a cushion for the rocket as it hits the thicker atmosphere?

My understanding is that the boostback burn is mainly intended to reverse the horizontal velocity away from the landing pad, without seriously effecting the vertical velocity, so that the first stage performs a high arc back to the neighborhood of the landing pad. The reentry burn kills most of the vertical velocity as it reenters the atmosphere, and the landing burn's purpose is obvious. So yes, it seems to me that if the ASDS is at the proper location, the boostback burn would not be needed, unless some trajectory fine-tuning is still required.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: modemeagle on 12/26/2015 10:33 PM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?

was the middle burn to create a cushion for the rocket as it hits the thicker atmosphere?

My understanding is that the boostback burn is mainly intended to reverse the horizontal velocity away from the landing pad, without seriously effecting the vertical velocity, so that the first stage performs a high arc back to the neighborhood of the landing pad. The reentry burn kills most of the vertical velocity as it reenters the atmosphere, and the landing burn's purpose is obvious. So yes, it seems to me that if the ASDS is at the proper location, the boostback burn would not be needed, unless some trajectory fine-tuning is still required.

The first burn should be used to kill some of the forward velocity as well as give it lateral acceleration toward the ASDS.  I would not expect it to sit exactly below the trajectory of the launch, but a little to the side.  Has anybody done a comparison of the location of the ASDS and the trajectory of the launch?


EDIT:  Appears CRS-6 ASDS was 7nm from the flight path, using the FCC license to determine the location.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 12/26/2015 11:52 PM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?
Because it'd go too far down-range, I believe. While they could put the drone ship all the way to the ballistic crash point of the booster at staging, it's easier for operations if they're closer to shore.

...I believe.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 12/27/2015 01:35 AM
Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mongo62 on 12/27/2015 01:38 AM
Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.

No one is doubting the need for an entry burn. The issue is whether a preceding boostback burn is always required, even with ASDS landings.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 12/27/2015 03:02 AM
No one is doubting the need for an entry burn. The issue is whether a preceding boostback burn is always required, even with ASDS landings.
No, its not. Boostback is only needed to change ballpark landing target coordinates. For instance OG2 boostback increased entry burn intensity (by raising apogee from 100+Km to 200Km, substantially increasing initial entry speed). A scenario where boostback is mandatory requires boostback to always reduce entry speed, which is totaly contradictory with OG2 return profile. If entry speed is very high, just begin entry burn a little earlier or add another engine to the burn.

PS: I'm not a rocket engineer, but this is basic physics, logic and rudimentary orbital mechanics. It seems like a slam dunk conclusion.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 12/27/2015 04:12 AM
Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.

That's likely, plus I believe it also provides stability in a region where the fins are still not effective.

This is the biggest piece of secret sauce they developed.  When and how much.  They were lucky and got it to work on the first try (CASSIOPE IIRC) but then made it work on the subsequent launch that had much lower margins...  And it has worked on each and every subsequent launch.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 12/27/2015 04:20 AM
I cannot see why three burns. The stage could follow its trajectory until reentry without burn. Then an extended reentry burn and the landing burn, that would be two. What am I missing?

was the middle burn to create a cushion for the rocket as it hits the thicker atmosphere?

My understanding is that the boostback burn is mainly intended to reverse the horizontal velocity away from the landing pad, without seriously effecting the vertical velocity, so that the first stage performs a high arc back to the neighborhood of the landing pad. The reentry burn kills most of the vertical velocity as it reenters the atmosphere, and the landing burn's purpose is obvious. So yes, it seems to me that if the ASDS is at the proper location, the boostback burn would not be needed, unless some trajectory fine-tuning is still required.

Right, the boostback burn is just needed for an initial aim towards its landing position. Should the ASDS be near the ballistic entry point, the boostback/aim burn would not be needed.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 12/27/2015 05:15 AM
Here's a question to which I don't have the answer, though -- is the ballistic trajectory worse in terms of heating regime than the looped-back trajectory achieved with the boostback burn?  The boostback does cancel out the rather significant downrange velocity, after all.

I recall that ballistic trajectories have high deceleration rates; do they also have hotter entries than a loop-back?  If so, would that limit the speed and angle at which a falcon can enter on a ballistic trajectory, even with an engine's exhaust pushing back the entry heating?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 12/27/2015 05:17 AM
Here's a question to which I don't have the answer, though -- is the ballistic trajectory worse in terms of heating regime than the looped-back trajectory achieved with the boostback burn?  The boostback does cancel out the rather significant downrange velocity, after all.

I recall that ballistic trajectories have high deceleration rates; do they also have hotter entries than a loop-back?  If so, would that limit the speed and angle at which a falcon can enter on a ballistic trajectory, even with an engine's exhaust pushing back the entry heating?

Yes, you might be right.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 12/27/2015 05:33 AM
Here's a question to which I don't have the answer, though -- is the ballistic trajectory worse in terms of heating regime than the looped-back trajectory achieved with the boostback burn?  The boostback does cancel out the rather significant downrange velocity, after all.

I recall that ballistic trajectories have high deceleration rates; do they also have hotter entries than a loop-back?  If so, would that limit the speed and angle at which a falcon can enter on a ballistic trajectory, even with an engine's exhaust pushing back the entry heating?
Not a problem. Why can't the entry / interface burn start a few seconds earlier and reorient the stage as needed with cold gas thrusters ?

But I think that's an issue in re-entry from orbit, not in stage 1 ballistic trajectory. 8000Km/h is far less than 28300Km/h LEO orbital speed.

That will be an issue when S2 reuse comes to play, but that is likely to be dealt with heat shield ablative surfaces (slowing down from orbital speed to a survivable speed similar to S1 re-entry would require a lot of fuel, ablative heat shield would require much less mass).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JamesH on 12/27/2015 10:28 AM
Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.

That's likely, plus I believe it also provides stability in a region where the fins are still not effective.

This is the biggest piece of secret sauce they developed.  When and how much.  They were lucky and got it to work on the first try (CASSIOPE IIRC) but then made it work on the subsequent launch that had much lower margins...  And it has worked on each and every subsequent launch.

I don't believe they were lucky.

I believe they have good engineers, who know what they are doing.  As shown by the fact it has worked on every launch. Including the first.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 12/27/2015 12:18 PM
Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.

That's likely, plus I believe it also provides stability in a region where the fins are still not effective.

This is the biggest piece of secret sauce they developed.  When and how much.  They were lucky and got it to work on the first try (CASSIOPE IIRC) but then made it work on the subsequent launch that had much lower margins...  And it has worked on each and every subsequent launch.

I don't believe they were lucky.

I believe they have good engineers, who know what they are doing.  As shown by the fact it has worked on every launch. Including the first.

Talent, no doubt... but an environment that thrives on innovation and empirical testing (with its associated kabooms) is as vital.  They don't study problems to death -- they try things that will probably be close to the answer, watch the response, and adjust before trying again.  Brilliant.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jakusb on 12/27/2015 12:40 PM

Also, I believe the entry burn is designed to create a plasma sheath between the atmospheric heating region and the octoweb.  In other words, it acts to provide protection against entry heating.  And trust me, at the altitude from, and speed at which the first stage comes in, there is significant entry heating.  The entry burn keeps that from affecting the stage itself, without needing to cover the base of the stage with some additional TPS rated for entry heating.

That's likely, plus I believe it also provides stability in a region where the fins are still not effective.

This is the biggest piece of secret sauce they developed.  When and how much.  They were lucky and got it to work on the first try (CASSIOPE IIRC) but then made it work on the subsequent launch that had much lower margins...  And it has worked on each and every subsequent launch.

I don't believe they were lucky.

I believe they have good engineers, who know what they are doing.  As shown by the fact it has worked on every launch. Including the first.

Talent, no doubt... but an environment that thrives on innovation and empirical testing (with its associated kabooms) is as vital.  They don't study problems to death -- they try things that will probably be close to the answer, watch the response, and adjust before trying again.  Brilliant.
I guess that is one of the most intriguing aspects of SpaceX: the pushing the envelope at any chance they get. Balancing almost perfectly between science and practice. Failure is not only an option, it is part of shifting boundaries almost no-one seems to dare.
A bit of luck is needed at this too, but they seem to minimize the luck factor to a minimum. And very successfully as it seems.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 12/27/2015 12:43 PM
Here's a question to which I don't have the answer, though -- is the ballistic trajectory worse in terms of heating regime than the looped-back trajectory achieved with the boostback burn?  The boostback does cancel out the rather significant downrange velocity, after all.

I recall that ballistic trajectories have high deceleration rates; do they also have hotter entries than a loop-back?  If so, would that limit the speed and angle at which a falcon can enter on a ballistic trajectory, even with an engine's exhaust pushing back the entry heating?

At staging, S1 has a significant upward velocity, but that will be diminished by about 10m/s per sec., or add to downward velocity 1000m/s for every 100 s of free flight. For boostback, they have to calculate the amount of time it will take to get to the landing site at the planned horizontal velocity and make sure they have enough upward velocity to stay above the atmosphere for most of that distance. That could include adding upward v in the boostback if needed, but all the added upward v will come back in downward v due to gravity, and need to be killed propulsively. For landing at sea, they don't have to do a boostback burn unless they want to keep the landing site  closer to shore, just let it follow the ballistic arc and do a reentry burn to make it survivable.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 12/27/2015 01:36 PM
OK --to try and wrap up this little side-thread, here, let me try and put the question a little better:

Will a ballistic landing downrange, with little to no boostback burn (as will be required for some heavier payloads), create a more challenging entry environment, in terms of both entry heating and deceleration stresses, than entry after a boostback to an RTLS, or near-RTLS, profile?  And does the Falcon have limits beyond which it can't survive a ballistic entry without a boostback (or at least a lofting/shaping) burn?  Or is the entry burn capable of handle all possible conditions, from pure unmodified ballistic entries to full boostback RTLS trajectories?

I guess I'm trying to visualize the boundary between the case of being able to recover a first stage, and the case where the stage must be expended.  I know there's a line out there, defined by the remaining delta-V in the stage after BECO, below which there is not enough energy left to achieve both an entry burn and a landing burn.  But are there ballistic trajectories that are non-survivable, even if there is theoretically enough energy left in the stage to accomplish a downrange recovery?  In other words, is the definition of "must be expended" entirely defined by the remaining delta-V in the stage, or does the entry environment also play a role in defining a mission where the first stage cannot be recovered?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 12/27/2015 01:51 PM
By environmental conditions do you mean air temp, pressure and wind speed? I'm guessing wind speed and sea state may be significant, but not temperature and barometric pressure. Apart from that, it is also a matter of probabilities as far as actual engine performance that may leave more or less fuel once the velocity target is reached for MECO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 12/27/2015 02:09 PM
By environmental conditions do you mean air temp, pressure and wind speed? I'm guessing wind speed and sea state may be significant, but not temperature and barometric pressure. Apart from that, it is also a matter of probabilities as far as actual engine performance that may leave more or less fuel once the velocity target is reached for MECO.

No -- I'm talking about the entry conditions -- speed, angle of entry, tie of peak heating, and deceleration stresses.  For example, let's say that a boostback to an RTLS trajectory results in deceleration stresses of about 5G to 6G, whereas a ballistic entry results in 15G to 20G stresses.  Or there is a difference between 30 seconds of entry heating and, say, two minutes, or a significant increase in entry heating, from a ballistic to an RTLS trajectory?  Are there outlier conditions on ballistic entries where the deceleration and thermal stresses result in breakup of the stage?

Again, not talking about the wind conditions at the desired landing point, or the sea state.  I'm talking about surviving the entry back into the atmosphere, and whether or not there is a point at which a Falcon stage will not survive a ballistic entry, even if it has enough delta-V on paper to perform entry and landing burns.  Or is the question of whether or not a given trajectory allows stage recovery based solely on the remaining delta-V in the stage, and the entry conditions are not ever going to be a limiting factor?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cro-magnon gramps on 12/27/2015 02:18 PM
Is there an update thread for the SES-9 SpaceX Mission... I'd like to know more details about where this all stands in terms of Launch Readiness ie is the LV ready, is the PL ready, what is the hold up...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 12/27/2015 02:27 PM
By environmental conditions do you mean air temp, pressure and wind speed? I'm guessing wind speed and sea state may be significant, but not temperature and barometric pressure. Apart from that, it is also a matter of probabilities as far as actual engine performance that may leave more or less fuel once the velocity target is reached for MECO.

No -- I'm talking about the entry conditions -- speed, angle of entry, tie of peak heating, and deceleration stresses.  For example, let's say that a boostback to an RTLS trajectory results in deceleration stresses of about 5G to 6G, whereas a ballistic entry results in 15G to 20G stresses.  Or there is a difference between 30 seconds of entry heating and, say, two minutes, or a significant increase in entry heating, from a ballistic to an RTLS trajectory?  Are there outlier conditions on ballistic entries where the deceleration and thermal stresses result in breakup of the stage?

Again, not talking about the wind conditions at the desired landing point, or the sea state.  I'm talking about surviving the entry back into the atmosphere, and whether or not there is a point at which a Falcon stage will not survive a ballistic entry, even if it has enough delta-V on paper to perform entry and landing burns.  Or is the question of whether or not a given trajectory allows stage recovery based solely on the remaining delta-V in the stage, and the entry conditions are not ever going to be a limiting factor?

I think the answer is yes, there are limits to all these parameters, and the model the reentry using computational flow dynamics simulations to work out the optimal trajectory. The remaining variation can mostly be made up with grid fin control to adjust stage attitude, lift and drag.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 12/27/2015 02:32 PM
No -- I'm talking about the entry conditions -- speed, angle of entry, tie of peak heating, and deceleration stresses.  For example, let's say that a boostback to an RTLS trajectory results in deceleration stresses of about 5G to 6G, whereas a ballistic entry results in 15G to 20G stresses.  Or there is a difference between 30 seconds of entry heating and, say, two minutes, or a significant increase in entry heating, from a ballistic to an RTLS trajectory?

Maybe I'm missing something and perhaps this is just semantics, but the only entry type a F9 stage can perform is effectively a ballistic entry. It has no significant lift, the grid fins serve only to fine-tune the landing point, I don't think they have enough control authority to significantly shallow-up the trajectory. The only difference between trajectories it can do is the entry angle you set up.

Also, dynamic pressure loading on reentry is likely to be the driving factor (trying to crush the stage, i.e. the G loading you mention), not reentry heating. The part that would experience most heating is the engine section and it already carries TPS anyway.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 12/27/2015 02:54 PM
Lift is quite significant in that a small amount of lift from high altitude can make a difference of several km to the landing point. They adjust the stage orientation control that lift.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 12/27/2015 03:34 PM
Is there an update thread for the SES-9 SpaceX Mission... I'd like to know more details about where this all stands in terms of Launch Readiness ie is the LV ready, is the PL ready, what is the hold up...

Not yet, it's too early. The Jason-3 update thread was only created yesterday.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 12/27/2015 05:01 PM
No -- I'm talking about the entry conditions -- speed, angle of entry, tie of peak heating, and deceleration stresses.  For example, let's say that a boostback to an RTLS trajectory results in deceleration stresses of about 5G to 6G, whereas a ballistic entry results in 15G to 20G stresses.  Or there is a difference between 30 seconds of entry heating and, say, two minutes, or a significant increase in entry heating, from a ballistic to an RTLS trajectory?

Maybe I'm missing something and perhaps this is just semantics, but the only entry type a F9 stage can perform is effectively a ballistic entry. It has no significant lift, the grid fins serve only to fine-tune the landing point, I don't think they have enough control authority to significantly shallow-up the trajectory. The only difference between trajectories it can do is the entry angle you set up.

...Which is exactly what the poster is asking about. A relatively shallow re-entry (from no boost-back) is quite different from an almost vertical re-entry. (which this last landing used)

My guess would be that it would be handled by making the braking/re-entry burn as long as needed, to reach a target velocity at ~40km. Didn't the CASSIOPE mission skip the boost-back burn? See the CASSIOPE video here, starting at 2:40:

https://www.youtube.com/watch?v=RtDbDMRG3q8
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 12/27/2015 05:06 PM
Boost-back zeroes out the horizontal velocity component, and then adds the minimal possible reverse horizontal velocity.

So a forward reentry will be faster and shallower, unless they correct it.

Again - the reentry parameters are the secret sauce.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 12/27/2015 05:07 PM
No -- I'm talking about the entry conditions -- speed, angle of entry, tie of peak heating, and deceleration stresses.  For example, let's say that a boostback to an RTLS trajectory results in deceleration stresses of about 5G to 6G, whereas a ballistic entry results in 15G to 20G stresses.  Or there is a difference between 30 seconds of entry heating and, say, two minutes, or a significant increase in entry heating, from a ballistic to an RTLS trajectory?

Maybe I'm missing something and perhaps this is just semantics, but the only entry type a F9 stage can perform is effectively a ballistic entry. It has no significant lift, the grid fins serve only to fine-tune the landing point, I don't think they have enough control authority to significantly shallow-up the trajectory. The only difference between trajectories it can do is the entry angle you set up.

...Which is exactly what the poster is asking about.

Yeah, but he was talking about RTLS and ballistic trajectories as if they're somehow different. My point was that they're both really ballistic.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 12/27/2015 06:02 PM


Yeah, but he was talking about RTLS and ballistic trajectories as if they're somehow different. My point was that they're both really ballistic.

Until the super/hypersonic retropulsion starts

The original question we drifted on to this really boils down (at least as I understand it) to "what significant differences are there between the supersonic retropulsion phase and landing in a downrange landing or an RTLS landing".

I would agree that the RTLS case has the stage moving somewhat slower against the surrounding air but add that it is going from low pressure to higher pressure quicker because the vertical velocity is much higher. The ADSL case should be going as much as 1km/s higher in absolute velocity but with a rate of descent that is much lower when that retropulsion starts. Once retropulsion is complete the coast phase at (anyone with a better number correct me please) about 800m/s slowing towards terminal velocity before the final landing burn should be steeper for the RTLS but the forces and stresses should not be much different.

Lastly the shape of the course from the start of the final burn is slightly different

Note that the  ΔV required for RTLS vs downrange landing is about double given the rest of the course elements being the same and that in absolute terms if your stage has a downrange velocity of 2km/s then it needs to boost back with more than 3kms with a slight upward component to the vector as soon as it can after stage separation and then do a supersonic retro burn from about 2km/s to 0.8 with probably more than 50% component of vertical velocity compared to a single retropulsion burn from about 3km/s (vertical plus horizontal component) to 0.8. Then in both cases about the same landing burn will be made.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cro-magnon gramps on 12/27/2015 06:26 PM
Is there an update thread for the SES-9 SpaceX Mission... I'd like to know more details about where this all stands in terms of Launch Readiness ie is the LV ready, is the PL ready, what is the hold up...

Not yet, it's too early. The Jason-3 update thread was only created yesterday.

Thx FST with it being NET JAN I was hoping that there might actually be some news about it's progress...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 12/28/2015 03:51 AM
OK --to try and wrap up this little side-thread, here, let me try and put the question a little better:

Will a ballistic landing downrange, with little to no boostback burn (as will be required for some heavier payloads), create a more challenging entry environment, in terms of both entry heating and deceleration stresses, than entry after a boostback to an RTLS, or near-RTLS, profile?  And does the Falcon have limits beyond which it can't survive a ballistic entry without a boostback (or at least a lofting/shaping) burn?  Or is the entry burn capable of handle all possible conditions, from pure unmodified ballistic entries to full boostback RTLS trajectories?

I guess I'm trying to visualize the boundary between the case of being able to recover a first stage, and the case where the stage must be expended.  I know there's a line out there, defined by the remaining delta-V in the stage after BECO, below which there is not enough energy left to achieve both an entry burn and a landing burn.  But are there ballistic trajectories that are non-survivable, even if there is theoretically enough energy left in the stage to accomplish a downrange recovery?  In other words, is the definition of "must be expended" entirely defined by the remaining delta-V in the stage, or does the entry environment also play a role in defining a mission where the first stage cannot be recovered?

Well, your first comment about wrapping up the side-thread, now a dozen or so posts later looks like the side thread is still going on.  Including this-

I seem to have some knowledge relevant to the necessity of boostback but my memory is foggy and a quick search didn't come up with anything useful.  Posting here in hopes that it triggers someone else to remember and flush out the details.  [IIRC] All ocean recovery experiments including the ones prior to ASDS platforms have had what SpaceX has called a boostback burn even though that burn was only to slow horizontal velocity not reverse it (as was done with the CCAFS landed Orbcomm-2) - with one exception.  The one exception was relatively recently, approximately Eutelsat, in March.  That heavy payload took too much energy to do a boostback burn.  It seems as if  there was a tweet or some other source that stated the kinetic energy being carried into the re-entry burn was to be 8x what had succeeded on previous recovery attempts.  And it made it through.[/IIRC]

I can't emphasize enough that this is only foggy memory stuff, not necessarily fact.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: John Alan on 12/28/2015 05:40 AM
OK --to try and wrap up this little side-thread, here, let me try and put the question a little better:

Will a ballistic landing downrange, with little to no boostback burn (as will be required for some heavier payloads), create a more challenging entry environment, in terms of both entry heating and deceleration stresses, than entry after a boostback to an RTLS, or near-RTLS, profile?  And does the Falcon have limits beyond which it can't survive a ballistic entry without a boostback (or at least a lofting/shaping) burn?  Or is the entry burn capable of handle all possible conditions, from pure unmodified ballistic entries to full boostback RTLS trajectories?

I guess I'm trying to visualize the boundary between the case of being able to recover a first stage, and the case where the stage must be expended.  I know there's a line out there, defined by the remaining delta-V in the stage after BECO, below which there is not enough energy left to achieve both an entry burn and a landing burn.  But are there ballistic trajectories that are non-survivable, even if there is theoretically enough energy left in the stage to accomplish a downrange recovery?  In other words, is the definition of "must be expended" entirely defined by the remaining delta-V in the stage, or does the entry environment also play a role in defining a mission where the first stage cannot be recovered?

Well, your first comment about wrapping up the side-thread, now a dozen or so posts later looks like the side thread is still going on.  Including this-

I seem to have some knowledge relevant to the necessity of boostback but my memory is foggy and a quick search didn't come up with anything useful.  Posting here in hopes that it triggers someone else to remember and flush out the details.  [IIRC] All ocean recovery experiments including the ones prior to ASDS platforms have had what SpaceX has called a boostback burn even though that burn was only to slow horizontal velocity not reverse it (as was done with the CCAFS landed Orbcomm-2) - with one exception.  The one exception was relatively recently, approximately Eutelsat, in March.  That heavy payload took too much energy to do a boostback burn.  It seems as if  there was a tweet or some other source that stated the kinetic energy being carried into the re-entry burn was to be 8x what had succeeded on previous recovery attempts.  And it made it through.[/IIRC]

I can't emphasize enough that this is only foggy memory stuff, not necessarily fact.

DSCOVR was the fast and hot one way downrange...  ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 12/28/2015 05:26 PM
DSCOVR was the fast and hot one way downrange...  ;)

Can you confirm or deny my recollections of no boostback burn and 8x kinetic energy at atmospheric interface for DSCOVR?  Looking back I see that DSCOVR was the one that was headed to the ASDS but the ASDS was not in position due to a severe storm out there.  It did have a landing on the water surface that was within 10M, which is IIRC, the first to do so.

Interesting discussion but very OT, so I'll just throw this in "SES-9".
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 12/28/2015 06:49 PM
DSCOVR was the fast and hot one way downrange...  ;)

Can you confirm or deny my recollections of no boostback burn and 8x kinetic energy at atmospheric interface for DSCOVR?  Looking back I see that DSCOVR was the one that was headed to the ASDS but the ASDS was not in position due to a severe storm out there.  It did have a landing on the water surface that was within 10M, which is IIRC, the first to do so.

Interesting discussion but very OT, so I'll just throw this in "SES-9".

You may be remembering this tweet from Elon.

Quote
Elon Musk – Verified account ‏@elonmusk

Rocket reentry will be much tougher this time around due to deep space mission. Almost 2X force and 4X heat. Plenty of hydraulic fluid tho.
11:43 AM - 8 Feb 2015
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/04/2016 03:10 PM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 01/04/2016 03:32 PM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...
mapped

(Isn't 1800 m/sec the velocity change needed to circularize at Geo? Doesn't 1800 m/sec reflect a lower perigee than the somewhat standard 1500 m/sec?)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/04/2016 03:36 PM
Doesn't 1800 m/sec reflect a lower perigee than the somewhat standard 1500 m/sec?

Higher inclination of the GTO orbit, usually.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/04/2016 03:40 PM
(Isn't 1800 m/sec the velocity change needed to circularize at Geo? Doesn't 1800 m/sec reflect a lower perigee than the somewhat standard 1500 m/sec?)

We use to call Cape GTO missions as GTO-1800. The reason is that a launch from the Cape will leave a 20+ degree inclination in a standard GTO mission. GTO-1500 is for a mission that gets to 0 inclination (and you only have to circularize from that). That's what Ariane 5 does (which launches from Kuru).

Yes, both -1800 and -1500 means m/s needed to circularize to GEO/0 inclination.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: The Amazing Catstronaut on 01/04/2016 03:43 PM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...

It always startles me how (deceptively) easy those applications look to fill out, although it's a lot more complex than they appear. What's the point of paperwork if it's not frightening?

May occur, but didn't they make similar applications practically every other time? Still holding out for an RTLS.

Edit: derp, wrong thread.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/04/2016 03:45 PM
Still holding out for an RTLS.

I'd be very impressed if SES-9 flight had the performance to do a RTLS...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: The Amazing Catstronaut on 01/04/2016 03:58 PM
Still holding out for an RTLS.

I'd be very impressed if SES-9 flight had the performance to do a RTLS...

And then there's me thinking this is the Jason 3 thread...  ::)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/04/2016 03:59 PM
Still holding out for an RTLS.

I'd be very impressed if SES-9 flight had the performance to do a RTLS...

If F9 FT S1 could RTLS after dispensing a 5,330kg GTO sat, then FH would probably be heavily delayed/cancelled and SpaceX would service the whole commercial market with the single stick.

Maybe in 10 years and with M1-Fs..XD
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: edkyle99 on 01/04/2016 04:06 PM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...

I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 01/04/2016 04:08 PM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...

I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 

 - Ed Kyle

*** only??? ***
How quickly things change.  ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 01/04/2016 04:09 PM
I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 
I would assume so, this has to be right at the margins of a recoverable flight even for F9FT.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Semmel on 01/04/2016 06:49 PM
I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 

My understanding is that they need the boost-back to target the landing site even when its the barge down range. My understanding can be wrong of course.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 01/04/2016 07:13 PM
I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 

My understanding is that they need the boost-back to target the landing site even when its the barge down range. My understanding can be wrong of course.

Yep, that is my understanding as well. A more proper term for the burn may simply be "aiming burn", since it doesn't always result in a boost-back. But it is there to aim the stage to the landing point.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: joek on 01/04/2016 10:53 PM
I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 
My understanding is that they need the boost-back to target the landing site even when its the barge down range. My understanding can be wrong of course.
Yep, that is my understanding as well. A more proper term for the burn may simply be "aiming burn", since it doesn't always result in a boost-back. But it is there to aim the stage to the landing point.

The CASSIOPE flight did only two burns: reentry and landing.  The first stage survived reentry but not landing.

All ASDS recovery attempts since have also done a third boostback-aiming-whatever burn.  However, that may have been because SpaceX wanted to test and refine the three-burns required for RTLS--not necessarily because it was absolutely required for ASDS-based recovery.

For downrange ASDS landing, it may be that two burns are sufficient and that the grid fins provide sufficient cross- and down-range control and precision.  That might explain why ASDS for this attempt appears to be farther down-range than previously(?): less propellant spent for recovery means more for payload.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/04/2016 10:59 PM
All ASDS recovery attempts since have also done a third boostback-aiming-whatever burn.  However, that may have been because SpaceX wanted to test and refine the three-burns required for RTLS--not necessarily because it was absolutely required for ASDS-based recovery.

I'm not sure letting the stage coast for such a long time after MECO (when its state vector can only be *so* close to preflight predict) is a good idea. There's only so much crossrange capability available during reentry phase (both powered and unpowered) once you realize you may be way off track. The 3rd burn may well be desirable, even if it's only a couple-of-second trim.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 01/04/2016 11:10 PM
Ullage issues would cause me to lose sleep...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 01/04/2016 11:16 PM
Ullage issues would cause me to lose sleep...

Why? They don't seem to have had any problems settling the propellant for those boost back/aiming burns, since the engines have started properly.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/04/2016 11:18 PM
Ullage issues would cause me to lose sleep...

Not when you have cold nitrogen thrusters and a good time margin to re-light.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Herb Schaltegger on 01/05/2016 01:17 AM
Ullage issues would cause me to lose sleep...

In addition to what Lars-J and Dante80 said, there's also the fact that even if the first burn in the sequence is the re-entry burn, there would probably already be sufficient aerodynamic drag acting on the stage to settle the prop by deceleration.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 01/05/2016 01:39 AM

Ullage issues would cause me to lose sleep...

In addition to what Lars-J and Dante80 said, there's also the fact that even if the first burn in the sequence is the re-entry burn, there would probably already be sufficient aerodynamic drag acting on the stage to settle the prop by deceleration.
Wouldn't that settle the prop away from the supply lines located at bottom of the tank.

Also, for clarity, I know the folks at SX have this pretty well sorted, as proof is in the landing - so to say - but it's just that it causes me angst. I guess my point is without the third engine relight to resettle the prop, would there be a potential for the prop to migrate past the baffle system and decrease probability of a successful relight? Perhaps that's a consideration for the quantity of relights as well...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 01/05/2016 01:44 AM

Ullage issues would cause me to lose sleep...

In addition to what Lars-J and Dante80 said, there's also the fact that even if the first burn in the sequence is the re-entry burn, there would probably already be sufficient aerodynamic drag acting on the stage to settle the prop by deceleration.
Wouldn't that settle the prop away from the supply lines located at bottom of the tank.

Nope, think about it. The rocket is falling tail first, slowed down by the atmosphere, the propellant will naturally pool at the bottom of the tank. No ullage effort is needed for the braking and landing burns.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 01/05/2016 01:54 AM
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000)

Barging may occur after all. That's interesting (GTO-1800? sub-synchronous flight?)

NET 23-JAN-2016

Barge location (its far away this time, about 660km out)...

I wonder if there will be a "boost back" burn at all on this flight.  Perhaps reentry and landing only? 

 - Ed Kyle

*** only??? ***
How quickly things change.  ;)

And isn't that great?  Just think of the wonders we could become  Numb to in 5-10 years.

I think there will be 3 burns.  For the same reasons that deep space missions look for multiple course corrections.  Earlier corrections take less fuel for equal amounts of change.  Maybe it's less than 3 engines and shorter in duration but there will be a burn to get them as close as possible to the center of the window.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 01/05/2016 06:09 AM
Maybe this landing attempt, even if the vehicle doesn't reach the ASDS, will help SpaceX determine exactly how much targeting they can get from the grid fins, and how much structural loading the stage can tolerate?

Is it fair to assume that if the grid fins "wanted" to do so, they could stress the stage during reentry with so much bending that it would break? But that just short of that braking point the stage would experience a lot of (potentially useful for aiming) aerodynamic force?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 01/05/2016 03:36 PM
So, thinking about the flight profile of an F9 1st stage...

The rocket is under guidance until MECO.  Presumably the guidance here is very precise, to put the 2nd stage on the right trajectory at the right velocity.  MECO is in vacuum, so the trajectory after MECO will be very predictable.  The only things that would alter that trajectory in a possibly unpredictable way would be stage separation and any thrust transients during 1st stage engine shutdown.  I would expect these to be pretty minor.

It doesn't seem to me like, assuming nominal flight, there would be enough deviation from the projected trajectory to require the "boostback/guidance" burn in vacuum.  I would think the entry interface burn (which can do some of the fine tuning) and the grid fins together would be sufficient.  I think this will likely be essential for the really heavy GTO birds (e.g. SES-9 at ~5300kg) to be able to make a barge landing while still achieving -1800m/s of GEO.

Just my two cents and change...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/05/2016 04:16 PM
We can pretty much expect that a boost-back burn would be a lot shorter than in a RTLS lower energy mission, especially since you have the ability to position the barge closer to the "free-fall" ballistic trajectory.

Having said that, we cannot conclusively say that there is not going to be a boost-back burn. For a couple of reasons.

1. It might be essential for precise positioning.
2. Without it, limitations in guidance components (for example, amount of hydraulic fluid for the fins) might not suffice.
3. A boost-back burn might serve more purposes (like making re-entry from a high energy mission easier on the rocket vs a free-fall ballistic trajectory, or something else).

All in all, we don't know at this point. Lets see how this unfolds.. :)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nisse on 01/05/2016 09:53 PM
Seem spacecraft has arrived. When could we see it launched?

https://www.youtube.com/watch?v=fZrVVp6m7RE
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/05/2016 10:41 PM
Seem spacecraft has arrived. When could we see it launched?

[youtube]fZrVVp6m7RE[/youtube]

-This thing is badass, take a look at that fire extinguisher on the side. As well as the lights on the bottom corners and the...oh...look, a helicopter!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 01/06/2016 03:24 AM
Utter speculation on the boostback burn question...

We saw on the last one (Orbcomm-2) that even though there was a full boostback burn which more or less reversed the horizontal velocity the vertical velocity remained high and the stage doubled its altitude after release of the second stage.  Obviously they could have aligned the thrust vector to cancel more of that vertical if it was desired.  Which leaves me thinking that they don't want to re-enter the thin upper bits of the atmosphere at a skimming angle but rather they want to come in more vertical.  Why?  Hmm... Because the top of the atmosphere (as defined by the altitude that any given pressure occurrs) varies over time due to atmospheric pressure changes.  Which means that a more vertical approach would give a more predictable targeting.  Which leads me to think that they'd want as much boostback burn as possible even with an ASDS.  ...Unless the objective of this landing test is to define how much heating is too much.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: S.Paulissen on 01/06/2016 03:32 AM
Less dV to reach the landing site.  Seems pretty straightforward.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mme on 01/06/2016 03:52 AM
Utter speculation on the boostback burn question...

We saw on the last one (Orbcomm-2) that even though there was a full boostback burn which more or less reversed the horizontal velocity the vertical velocity remained high and the stage doubled its altitude after release of the second stage.  Obviously they could have aligned the thrust vector to cancel more of that vertical if it was desired.  Which leaves me thinking that they don't want to re-enter the thin upper bits of the atmosphere at a skimming angle but rather they want to come in more vertical.  Why?  Hmm... Because the top of the atmosphere (as defined by the altitude that any given pressure occurrs) varies over time due to atmospheric pressure changes.  Which means that a more vertical approach would give a more predictable targeting.  Which leads me to think that they'd want as much boostback burn as possible even with an ASDS.  ...Unless the objective of this landing test is to define how much heating is too much.
I believe it's conserving kinetic energy and picking as efficient of a return trajectory as possible.  Using ANY propellent to cancel vertical momentum is a waste of propellent.  Gravity will do it for free.  And the extra altitude is additional "hang time."  More time means less required horizontal velocity to cover the distance.

Or more succinctly:
Less dV to reach the landing site.  Seems pretty straightforward.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 01/06/2016 04:38 AM
I think this might be obvious (but then I'm basically a flat-Earther): will the location of the ASDS have direct line of sight to the booster at MECO?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/06/2016 04:58 AM
SFN is reporting SES-9 scheduled forJan. 23, time TBD.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deltaV on 01/06/2016 05:20 AM
Utter speculation on the boostback burn question...

We saw on the last one (Orbcomm-2) that even though there was a full boostback burn which more or less reversed the horizontal velocity the vertical velocity remained high and the stage doubled its altitude after release of the second stage.  Obviously they could have aligned the thrust vector to cancel more of that vertical if it was desired.  Which leaves me thinking that they don't want to re-enter the thin upper bits of the atmosphere at a skimming angle but rather they want to come in more vertical.  Why?  Hmm... Because the top of the atmosphere (as defined by the altitude that any given pressure occurrs) varies over time due to atmospheric pressure changes.  Which means that a more vertical approach would give a more predictable targeting.  Which leads me to think that they'd want as much boostback burn as possible even with an ASDS.  ...Unless the objective of this landing test is to define how much heating is too much.

A ballistic projectile such as a gun shell or Falcon first stage has range proportional to the product of the initial horizontal velocity component and initial vertical velocity component. See e.g. https://en.wikipedia.org/wiki/Range_of_a_projectile. Obviously Falcon's situation is more complicated; my point is that one needn't invoke alleged targeting difficulties to justify keeping a large vertical velocity component.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/06/2016 09:17 AM
SFN is reporting SES-9 scheduled forJan. 23, time TBD.

On a trivial note, this will be the fastest ever recycle of MCC-X for different missions. That said, it shouldn't be a big issue, especially if they use different teams for the two flights.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: lbiderman on 01/06/2016 12:45 PM
SFN is reporting SES-9 scheduled forJan. 23, time TBD.

On a trivial note, this will be the fastest ever recycle of MCC-X for different missions. That said, it shouldn't be a big issue, especially if they use different teams for the two flights.

I believe that having different launch pads and (probably, not sure though) processing teams with the previous flight allows a fast turn around.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/06/2016 01:08 PM
To re-iterate a little more about the projected capability for FT.

1. F9 v1.1 has "demonstrated" an expendable capability of ~ 4,850kg to GTO-1800. Two sets of data compound to that assertion.

a. The biggest GTO payload was the 4,707kg TurkmenAlem52E. It was placed in a roughly GTO-1765 orbit (180x36600x25.5)
b. Thaicom 6 (a 3,016kg sat) got to a GTO-1500 equivalent orbit (295x90000x22.5). This stretched S2 fuel reserves to almost complete depletion (according to USAF, which evaluated this flight as part of the SpaceX EELV certification procedure).

2. F9 FT as a whole is reported to be around 30% more capable than F1 v1.1

3. DPL (barging) costs about 15% payload.

This means that F9 FT has a theoretical capability of about 6,300kg to GTO-1800
Barging moves it to 5,355kg.
SES9 is 5330 kg.

Its looking very close. Depending on whether the rocket goes to DPL or not, as well as what the end orbit is, we are going to get a lot of info about the current Falcon variant capabilities. 

If this pans out, and RTLS removes another 15% of performance, F9 FT would be able to RTLS after sending a 4410kg payload to GTO-1800. This number is interesting for some of the following missions (quoting from here (http://forum.nasaspaceflight.com/index.php?topic=39167.msg1469559#msg1469559)):

Thaicom 8                      3100kg   GTO    Yes
ABS 2A, Eutelsat 117 West B   ~4000kg?  GTO    Possibly (based on ABS-3A, Eutelsat 115 West B mass)
JCSAT-14                      ~3400kg?  GTO    Probably (based on JCSAT-15 mass)
BulgariaSat-1                 ~3400kg?  GTO    Probably (based on JCSAT-15 mass, same SSL-1300 bus)
JCSAT-16                      ~3400kg?  GTO    Probably (based on JCSAT-15 mass)
KoreaSat-5                     4465kg   GTO    Possibly
Es'hail-2                     ~3000kg   GTO    Probably

If F9 FT performance upgrade over v1.1 I listed above is correct (some say its more, like 33%), then almost all the missions above would be eligible for RTLS, OR a better orbit than GTO-1800 + DPL.

In my view, the SES9 mission may be one of the most important milestones for this year. GTO is where the money is.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: saliva_sweet on 01/06/2016 01:35 PM
My mind is refusing to accept this possibility. Some called the RTLS a "sputnik moment" for the competition. But if SpaceX puts SES9 to GTO-1800 and gets the booster back... I don't even know what to think.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/06/2016 01:40 PM
My mind is refusing to accept this possibility. Some called the RTLS a "sputnik moment" for the competition. But if SpaceX puts SES9 to GTO-1800 and gets the booster back... I don't even know what to think.

SES9 cannot RTLS though (its more than 5 tonnes). "Only" land on the barge (DPL - Downrange Propulsive Landing).

Still, DPL would be something to witness...especially for the competitions' reactions..XD
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 01/06/2016 01:48 PM
My mind is refusing to accept this possibility. Some called the RTLS a "sputnik moment" for the competition. But if SpaceX puts SES9 to GTO-1800 and gets the booster back... I don't even know what to think.
I look forward to Mr Bezos tweet if SpaceX pull ASDS landing with SES-9 !

If SpaceX can do 6.3 tons to GEO-1800m/s with F9 FT expendable, they need to revise the Falcon Heavy up to 6.5 tons to GTO launch class quote on the website...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/06/2016 01:55 PM
if SpaceX puts SES9 to GTO-1800 and gets the booster back...

SES-9 was always claimed to be inserted into a subsynchronous transfer orbit. Is that synonymous to GTO-1800?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/06/2016 01:57 PM
if SpaceX puts SES9 to GTO-1800 and gets the booster back...

SES-9 was always claimed to be inserted into a subsynchronous transfer orbit. Is that synonymous to GTO-1800?

No, that is less.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 01/06/2016 01:58 PM
SES-9 was always claimed to be inserted into a subsynchronous transfer orbit. Is that synonymous to GTO-1800?
No, that would be more than 1800m/s short of GTO.  But that was F91.1, even with an ASDS landing the FT should be more capable.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 01/06/2016 01:59 PM
To re-iterate a little more about the projected capability for FT.

1. F9 v1.1 has "demonstrated" an expendable capability of ~ 4,850kg to GTO-1800. Two sets of data compound to that assertion.

a. The biggest GTO payload was the 4,707kg TurkmenAlem52E. It was placed in a roughly GTO-1765 orbit (180x36600x25.5)
b. Thaicom 6 (a 3,016kg sat) got to a GTO-1500 equivalent orbit (295x90000x22.5). This stretched S2 fuel reserves to almost complete depletion (according to USAF, which evaluated this flight as part of the SpaceX EELV certification procedure).

2. F9 FT as a whole is reported to be around 30% more capable than F1 v1.1

3. DPL (barging) costs about 15% payload.

This means that F9 FT has a theoretical capability of about 6,300kg to GTO-1800
Barging moves it to 5,355kg.
SES9 is 5330 kg.

Its looking very close. Depending on whether the rocket goes to DPL or not, as well as what the end orbit is, we are going to get a lot of info about the current Falcon variant capabilities. 

If this pans out, and RTLS removes another 15% of performance, F9 FT would be able to RTLS after sending a 4410kg payload to GTO-1800. This number is interesting for some of the following missions (quoting from here (http://forum.nasaspaceflight.com/index.php?topic=39167.msg1469559#msg1469559)):

Thaicom 8                      3100kg   GTO    Yes
ABS 2A, Eutelsat 117 West B   ~4000kg?  GTO    Possibly (based on ABS-3A, Eutelsat 115 West B mass)
JCSAT-14                      ~3400kg?  GTO    Probably (based on JCSAT-15 mass)
BulgariaSat-1                 ~3400kg?  GTO    Probably (based on JCSAT-15 mass, same SSL-1300 bus)
JCSAT-16                      ~3400kg?  GTO    Probably (based on JCSAT-15 mass)
KoreaSat-5                     4465kg   GTO    Possibly
Es'hail-2                     ~3000kg   GTO    Probably

If F9 FT performance upgrade over v1.1 I listed above is correct (some say its more, like 33%), then almost all the missions above would be eligible for RTLS, OR a better orbit than GTO-1800 + DPL.

In my view, the SES9 mission may be one of the most important milestones for this year. GTO is where the money is.
Pardon my ignorance, but could someone explain the meaning of GTO-1800, GTO-1500, etc? I thought that a GTO orbit had a fixed apogee at 42,164 km (26,000 mi) (center of earth) or 35,786 km (22,000 mi) (above sea level), which corresponds to the geostationary (GEO) altitude. (per el Goog). Additionally, you mention 90,000km apogee? I know it's my understanding that's lacking, but any pointer in the right direction is greatly appreciated.

Thanks,
john
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/06/2016 02:04 PM

Pardon my ignorance, but could someone explain the meaning of GTO-1800, GTO-1500, etc? I thought that a GTO orbit had a fixed apogee at 42,164 km (26,000 mi) (center of earth) or 35,786 km (22,000 mi) (above sea level), which corresponds to the geostationary (GEO) altitude. (per el Goog). Additionally, you mention 90,000km apogee? I know it's my understanding that's lacking, but any pointer in the right direction is greatly appreciated.

Thanks,
john

GTO = Geosynchronous transfer orbit (https://en.wikipedia.org/wiki/Geostationary_transfer_orbit)
GEO = Geostationary orbit (https://en.wikipedia.org/wiki/Geostationary_orbit)
GTO-1800 = Geosynchronous transfer orbit that needs an additional 1800m/s dV to reach Geostationary orbit
GTO-1500 = Geosynchronous transfer orbit that needs an additional 1500m/s dV to reach Geostationary  orbit

Super-synchronous (transfer) orbit = A Geosynchronous transfer orbit with an apogee (apsis (https://en.wikipedia.org/wiki/Apsis)) more than GEO altitude.
Sub-synchronous (transfer) orbit = A Geosynchronous transfer orbit with an apogee less than GEO altitude.

GEO = 35,786 km x 35,786 km x at 0 degrees inclination.
GTO-1800 = 185 km x 35,786 km at 27.0 deg inclination.
GTO-1500 = 185 km x 35,786 km at 0 deg inclination.

Cape Canaveral where most GTO payloads launch from is at a 27.0 deg inclination. This is why we tend to talk about GTO-1800

Kourou (where ArianeSpace Launches from) is very close to the equator. So, ArianeSpace tends to cancel all inclination when they launch GTO missions. That's why we are talking about GTO-1500.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 01/06/2016 02:14 PM
you mention 90,000km apogee? I know it's my understanding that's lacking, but any pointer in the right direction is greatly appreciated.

Minor addition to the explanation by Dante80

A supersynchronous transfer orbit with apogee higher than GEO, like 90,000km helps to correct the inclination. It is over all more efficient to go to high altitude, then correct the inclination to equatorial, then reduce altitude to GEO than correcting inclination at GEO. Probably this is counterintuitive, it was to me when I learned this.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: BabaORileyUSA on 01/06/2016 02:49 PM
Quote
     you mention 90,000km apogee? I know it's my understanding that's lacking, but any pointer in the right direction is greatly appreciated.


Minor addition to the explanation by Dante80

A supersynchronous transfer orbit with apogee higher than GEO, like 90,000km helps to correct the inclination. It is over all more efficient to go to high altitude, then correct the inclination to equatorial, then reduce altitude to GEO than correcting inclination at GEO. Probably this is counterintuitive, it was to me when I learned this.

Think of the apogee height of the transfer orbit in terms of the force-moment required to torque the orbit plane (from the inclination of the transfer orbit to an Equatorial inclination):  the longer the wrench (i.e. - semi-major axis), the less force is required to produce the same amount of torque.....
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Roy_H on 01/06/2016 05:40 PM
Quote
     you mention 90,000km apogee? I know it's my understanding that's lacking, but any pointer in the right direction is greatly appreciated.


Minor addition to the explanation by Dante80

A supersynchronous transfer orbit with apogee higher than GEO, like 90,000km helps to correct the inclination. It is over all more efficient to go to high altitude, then correct the inclination to equatorial, then reduce altitude to GEO than correcting inclination at GEO. Probably this is counterintuitive, it was to me when I learned this.

Think of the apogee height of the transfer orbit in terms of the force-moment required to torque the orbit plane (from the inclination of the transfer orbit to an Equatorial inclination):  the longer the wrench (i.e. - semi-major axis), the less force is required to produce the same amount of torque.....

Poor analogy, a longer wrench requires less force but more distance over which the force is applied, thus the same energy.

The further away from the planet, the slower the satellite is going. Changing direction at slower speed takes less energy. Think of driving a car around a corner at high speed the car has a lot of inertia and the tires have to exert a lot of turning force at low speed significantly less force is required, distance is the same.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 01/06/2016 09:01 PM
SFN is reporting SES-9 scheduled forJan. 23, time TBD.

Where to you see that?
When I look at (the non-member side of) SFN it still says "January TBD".
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/06/2016 09:11 PM
SFN is reporting SES-9 scheduled forJan. 23, time TBD.

Where to you see that?
When I look at (the non-member side of) SFN it still says "January TBD".

They changed it. Below is what it looked like when I posted.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Oli on 01/07/2016 02:28 AM
3. DPL (barging) costs about 15% payload.

If this pans out, and RTLS removes another 15% of performance

Very unlikely figures to GTO.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 01/07/2016 03:20 AM
3. DPL (barging) costs about 15% payload.

If this pans out, and RTLS removes another 15% of performance

Very unlikely figures to GTO.
It /is/ likely that upgrading to full thrust increased performance to GTO by ~30%, but less to LEO. And actually, with that much of a boost, it's quite possible that Full Thrust bargings have the same performance to GTO as v1.1 did.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/07/2016 09:55 AM
3. DPL (barging) costs about 15% payload.

If this pans out, and RTLS removes another 15% of performance

Very unlikely figures to GTO.

The source (http://shitelonsays.com/transcript/spacex-press-conference-september-29-2013-2013-09-29) for the quoted percentages is Elon Musk from 2013.

Quote
[Question on performance hit for attempting landing the first stage] We effectively lose, in terms of performance... It really depends on what we want to do with the stage if we were to do an ocean landing or a return to launch site landing. If we do an ocean landing, the performance hit is actually quite small at maybe in the order of 15%. If we do a return to launch site landing, it's probably double that, it's more like a 30% hit (i.e., 30% of payload lost).

Musk might have been talking only about LEO performance. I don't know if the performance penalty (as well as the FT performance upgrade) percentages are analogous between LEO and GTO. I would guess they are not.

The reason that SES9 in my view is an important mission, is that it will be able to give us (and the industry!) some answers on this. The end orbit of the satellite (as well as the post MECO behavior of the first stage) will indicate what the new vehicle capabilities are.

To be more precise.

With barging attempt

1. If the mission orbit is sub-synchronous (most likely scenario), then it would be somewhat safe to assume that the second stage will use all its performance to get there (leaving a safe residual margin of course). This enables us to extrapolate on maximum vehicle performance with barging.

2. If the mission orbit is GTO-1800, we are not going to get the actual maximum performance of the vehicle, but we will know at least the demonstrated performance wity barging.

With S1 being expendable

1. If the mission orbit is sub-synchronous and barging is not attempted, then we will be getting good info about what the vehicle cannot do. In that mission profile, it would also be somewhat safe to assume that the second stage will use all its performance to get there (leaving a safe residual margin of course).

2. If the mission orbit is GTO-1800 and barging is not attempted, then we will get some information on the demonstrated expandable GTO performance of the vehicle. What we will not get, is the exact payload/performance penalty needed for barging.



That's for Downrange Propulsive Landing. For RTLS, we really won't know what the performance penalty is. I'm willing to guess that it will be more than 30% vs expendable.

What are you thinking/expecting Oli?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 01/07/2016 10:32 AM
After the Orbcomm flight it was said both first and second stage performed nominally. It had been said they will attempt landing for SES-9, so I expect with nominal performance of the stages they will do that. So barge landing and let's see the orbit achieved.

I guess for the orbit SES will want at least GTO -1800m/s.

Edit: If they can achieve that, it will be bad news for Arianespace. They will point out that they offer GTO -1500m/s.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/07/2016 10:36 AM
I guess for the orbit SES will want at least GTO -1800m/s.

Not necessarily. The satellite does have a dual propulsion module, and the original plan before FT unveiled was to do a sub-synchronous orbit. Moreover, a future low contract price based on SpaceX trying to land the core is not out of the question (and would be weighed against the projected life cycle performance that a better GTO insertion would give without landing).

I am willing to assume that after CRS-7 (and maybe after ORB2 too), the schedule, order of launch and mission profile were things under negotiation between SES as SpaceX. What deal they struck at the end...we will know soon. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Norm38 on 01/10/2016 02:44 AM
If CRS-8 is Feb 7 like Bigelow says, then they're going to have to announce a date for this real
quick or it's not Jan.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 01/10/2016 02:15 PM
If CRS-8 is Feb 7 like Bigelow says, then they're going to have to announce a date for this real
quick or it's not Jan.

I saw a quick claim last week that there was a 1/23 target date posted on spaceflightnow launch schedule, but it's never showed up there. 

Maybe this is waiting for Jason-3 for reliability or manpower reasons.  Seems to me they are running out of time for January if they haven't even announced a date.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/10/2016 05:21 PM
If CRS-8 is Feb 7 like Bigelow says, then they're going to have to announce a date for this real
quick or it's not Jan.

I saw a quick claim last week that there was a 1/23 target date posted on spaceflightnow launch schedule, but it's never showed up there. 
>

It did, for a few hours.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Saabstory88 on 01/10/2016 08:03 PM
Some further thoughts on the performance margin of the flight. I ended up putting together a model to try to reconcile many of the mass and velocity estimates out there, and see how much of it makes sense. Some "known" items.

Per the "T-15m" press release, Orbcomm-2 mission:
Staging velocity for the DPL attempt will be approximately 8000 km/hr.
Upper stage stack is approximately 125 tons.

Per barge information:
DPL will take place around 660km downrange, with a ~18 km margin (642km - 678km)

From Users Guide:

MECO: 170 seconds
Separation: 175 seconds
Fairing Deploy: 220 seconds
SES - 1: 180 seconds
SECO - 1: 540 seconds

So I used these values, as well as some averages from Spaceflight 101, Space launch Report, etc... and used the following numbers for the calculations. I assumed 125t referred to both with fairings, and 10t reference payload.

S1 Dry: 20,461 kg
S1 Wet: 420,000kg

S2 Dry: 4,371kg
S2 Wet: 113,125kg

Fairings; 1,875kg (per half)

The results come out quite neatly. I used the throttle-down point from the Orbcomm mission to create the first stage throttle profile. Some results:

Meco Velocity: 2,531 m/s (7,901 km/hr)
S1 Apogee: 212km
S1 Downrange at 70km altitude (atmospheric interface): 638km
Throttle Regime #1 max acceleration: 3.63G
Throttle Regime #1 max acceleration: 2.937G

Stage Two required no major pitch corrections with this burn time. It seems that the first stage takes the brunt of the gravity losses.

S2 first Apogee: 223km
S2 SECO-1 altitude: 185.09km
S2 SECO-1 velocity: 7797.13 m/s
S2 Maximum acceleration: 3.67G
S2 Burnout Mass: 21,788kg

S2 Delta V remaining: 2,760 m/s
S2 Min/Max burn time remaining: 43.7 / 112 seconds
Users Guide Quoted GTO burn time: 66 seconds

Those are my thoughts on the SES-9 flight profile. I believe we will see DPL + -1,800 m/s GTO.

Edit: At Sea Level ISP, that leaves 1,623 m/s in the first stage.

Edit 2: The discrepancy in the S1 burnout velocity is the difference between including, and excluding the rotational assist of the Earth. As evidenced by the Orbcomm-2 mission, SpaceX's on screen, and quoted staging velocity figures do not include rotational assist.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 01/11/2016 02:40 AM
3.6 tons for the fairing doesn't sound right. You sure?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Saabstory88 on 01/11/2016 02:51 AM
3.6 tons for the fairing doesn't sound right. You sure?

I've heard lots of places say 4 tons for the whole fairing assembly, although I can't find the source. This number pops up a lot. Several placed have it listed at 1.5-2 tons. It seems likely to me that they have the weight of 1/2 of the whole assembly, ie, 1 fairing half.

Also, this is comparable to an Atlas fairing of similar surface area. In the end, I'd rather have the number high, than low, when in the mass category. Being pessimistic.

VVVVV As to below. I agree the mess estimates are low. Just because estimates aren't right doesn't mean they tell us nothing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 01/11/2016 02:55 AM
Space launch report gives figures that are too small for the upper stage. Musk said it was 125 tons (including payload).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/11/2016 03:00 AM
I remember reading an old thread where Jim was quoting a ~4ton fairing weight. I think his justification had something to do with horizontal integration and the fairing being a structural element.

Can't find the thread for the life of me.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: su27k on 01/11/2016 03:15 AM
I remember reading an old thread where Jim was quoting a ~4ton fairing weight. I think his justification had something to do with horizontal integration and the fairing being a structural element.

Can't find the thread for the life of me.

It's here: http://forum.nasaspaceflight.com/index.php?topic=37069.msg1357758#msg1357758
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: robert_d on 01/13/2016 01:48 PM
Do we know the location and status of the SES booster?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/13/2016 02:53 PM
There is a good chance that it is in SLC-40's HIF. The F9-21 core was installed onto pad 40 prior to its re-fire test using the crane. This suggests that that the pad's strong-back is in use as part of pre-launch for SES-9.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 01/13/2016 03:16 PM
There is a good chance that it is in SLC-40's HIF. The F9-21 core was installed onto pad 40 prior to its re-fire test using the crane. This suggests that that the pad's strong-back is in use as part of pre-launch for SES-9.
Isn't the launch platform with hold downs attached to the T/E/L assembly? I'm missing some aspect of how the T/E/L system works if the strongback is in the HIF and the launch platform with hold downs is on the pad...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 01/13/2016 03:29 PM
Yeah, so are we all. :) It's possible the F9-21 core is using the launch mount from LC-39A.  But no one knows exactly, we're hoping to get more information/photos/descriptions of crane campaigns/etc.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/13/2016 03:30 PM
There is a good chance that it is in SLC-40's HIF. The F9-21 core was installed onto pad 40 prior to its re-fire test using the crane. This suggests that that the pad's strong-back is in use as part of pre-launch for SES-9.

Isn't the launch platform with hold downs attached to the T/E/L assembly? I'm missing some aspect of how the T/E/L system works if the strongback in in the HIF and the launch platform with hold downs is on the pad...

I'm wondering if there may be a redundant hold-down platform to swap onto the T/E in the event of launch damage. Just haul it over to the pad, install it with a crane and then use the crane to install the core on top of it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 01/13/2016 03:33 PM
...or they unbolted the launch mount from the ses-9 T/E?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MechE31 on 01/13/2016 03:47 PM
My educated guesses from experience:

SES core in SLC-40 hangar, it is not on the TE, TE is stored outside, SLC-40 hangar cannot take 2 cores, crane is required to put an F9 on the TE (normally does using cranes inside hangar), pad cannot take a core without the TE/strongback on the pad.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 01/13/2016 04:09 PM
If the hangar can't take 2 cores and the OG2 core has to pass through the hangar on the way to the pad (my assumption), doesn't that imply no SES-9 core in hangar?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/13/2016 04:11 PM
Strongback clamps to S2. There's no S2.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 01/13/2016 04:16 PM
If the hangar can't take 2 cores and the OG2 core has to pass through the hangar on the way to the pad (my assumption), doesn't that imply no SES-9 core in hangar?

Looking at an (albeit old) aerial Google overhead view of SLC-40, there is a roadway to the pad that bypasses the HIF. This is also common sense as large construction equipment needs access to the structure regardless...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Darga on 01/13/2016 09:25 PM
Spaceflightnow is reporting NET Feb 6 now.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/14/2016 01:19 PM
Just out of interest, what are SFN's sources? People at the Eastern Range or source inside the launch providers?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: WHAP on 01/14/2016 07:18 PM
Just out of interest, what are SFN's sources? People at the Eastern Range or source inside the launch providers?

You're probably asking on the wrong website.  As soon as someone posts, another person will ask for proof of that proof.  SFN is a pretty reputable and reliable source.  Whether they get the actual range schedule or have sources, I would assume they vetted the information. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: tleski on 01/14/2016 07:20 PM
So, probably the thread should be renamed.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: bstrong on 01/15/2016 04:56 PM
One interesting possibility to speculate about is that the reason for the delay is that they learned a thing or two from the OG2 core and are making some small tweaks to this one as a result.

I didn't take this effect into account when placing my vote for number of launches in 2016.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: douglas100 on 01/15/2016 10:33 PM
Strongback clamps to S2. There's no S2.

Yep. The vehicle is on the launch mount and the T/E is attached, but the strongback is horizontal.

https://www.instagram.com/p/BAfiYwJgmn4/ (https://www.instagram.com/p/BAfiYwJgmn4/)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: shooter6947 on 01/18/2016 01:51 AM
Will JASON-3's liftoff on the first try allow SES-9 to fly in January?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 01/18/2016 02:04 AM
Probably not. After all, Jason and SES-9 launch from different pads, there is no relevance.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Herb Schaltegger on 01/18/2016 02:08 AM
Probably not. After all, Jason and SES-9 launch from different pads, there is no relevance.

Except for any shared resources such as launch support teams, supporting engineering and analysis personnel, trajectory analysis people, PR folks, customer relations and cntracting teams, legal and regulatory staff, etc.

That said, I don't see SES-9 launching until February.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: faramund on 01/18/2016 02:09 AM
Except that SpaceX seems to be showing that its systems are getting better. It used to seem like there were always delays. To the point that I began to be surprised when they did launch first time, and now.. its not quite so surprising.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 01/18/2016 02:59 AM
On-topic for SES-9, though (and perhaps for future launches) is whether or not a new fog launch constraint might be in the offing...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 01/18/2016 03:12 AM
On-topic for SES-9, though (and perhaps for future launches) is whether or not a new fog launch constraint might be in the offing...

Or a deicing protocol/system. Or a big dumb locking pin.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wannamoonbase on 01/18/2016 12:52 PM
Will JASON-3's liftoff on the first try allow SES-9 to fly in January?

The Atlas 5 has the range for Feb 3 so they'd have to improve enough to be ahead of that. 

Edit: A 3 week pace still provides a 16-17 launches a year.  That's darn good.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 01/18/2016 12:55 PM
It's after the Atlas V in Feb. Will set up an update thread.

Done - UPDATE Thread:
http://forum.nasaspaceflight.com/index.php?topic=39348.0
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ChrisC on 01/19/2016 08:27 PM
SES released this promo video about SES-9.  At the 1m22s minute point they show the coverage footprint, which spans Asia although they seem to be neatly carving out the area of Vietnam.  I know that Vietnam restricts access to satellite TV, but I doubt they have the political power to get commercial satellite operators to actually carve out Vietnam in the feedhorn designs that they put into orbit.  Does anyone know of the beam really is chopping out Vietnam?

https://www.youtube.com/watch?v=iJZV2oDzBao
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: IntoTheVoid on 01/19/2016 08:56 PM
SES released this promo video about SES-9.  At the 1m22s minute point they show the coverage footprint, which spans Asia although they seem to be neatly carving out the area of Vietnam.  I know that Vietnam restricts access to satellite TV, but I doubt they have the political power to get commercial satellite operators to actually carve out Vietnam in the feedhorn designs that they put into orbit.  Does anyone know of the beam really is chopping out Vietnam?

They don't claim that to be the satellite coverage. The caption on that image says "Prime Video Neighborhood". No special antennas are required to 'not' offer video.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 01/19/2016 11:27 PM
SES released this promo video about SES-9.  At the 1m22s minute point they show the coverage footprint, which spans Asia although they seem to be neatly carving out the area of Vietnam.  I know that Vietnam restricts access to satellite TV, but I doubt they have the political power to get commercial satellite operators to actually carve out Vietnam in the feedhorn designs that they put into orbit.  Does anyone know of the beam really is chopping out Vietnam?

https://www.youtube.com/watch?v=iJZV2oDzBao

Plausible deniability :)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 01/20/2016 08:49 AM
Does anyone know of the beam really is chopping out Vietnam?

It sure looks like they are. That should be possible in Ku band.

https://sat.ses.com/webservice/images/14438214

We're right in the middle of their Australian footprint! In case you're wondering why there's a spot beam over the middle of Australia, which has a very low population density, I suspect that its for the Pine Gap ground station located there. Adelaide also has a teleport in Technology Park next to the University of South Australia that is heavily used in defence communications with Afghanistan and Iraq. I presume that is why the spot beam is over us, instead of the major population centres of Sydney and Melbourne to the east.

https://sat.ses.com/webservice/images/14437994
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cuddihy on 01/20/2016 10:48 AM
By ITU agreement satellite frequency landing rights are controlled by the country they land in, period. In this case SES likely refused to give the Communist party of Vietnam veto right over what they broadcast, so Vietnam refused landing rights. Knowing that, SES designed the beams to comply (and to boost power where it's legal for them).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 01/20/2016 12:38 PM
Does anyone know of the beam really is chopping out Vietnam?
Given the odd shape of the beams, doubtless they are designed with some sort of optimization algorithm.  This would take as input a map, where some areas have a desired minimum power density, some areas are don't care, and (perhaps) some areas with a maximum limit (to avoid interference, for example).  If they specify the Vietnam region as "don't care", then the optimizer will naturally reduce the intensity there in order to increase the power density in places where you do care. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cuddihy on 01/20/2016 02:31 PM
No, I'm telling you Vietnam refused landing rights to SES so they had to avoid the country by beam management. If SES violates that Vietnam can sue them for interference. Forming the beam to comply happens to boost power available in other regions.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zed_Noir on 01/20/2016 06:07 PM
No, I'm telling you Vietnam refused landing rights to SES so they had to avoid the country by beam management. If SES violates that Vietnam can sue them for interference. Forming the beam to comply happens to boost power available in other regions.

Does the countries adjacent to Vietnam also lose coverage as well?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: launchwatcher on 01/20/2016 06:27 PM
No, I'm telling you Vietnam refused landing rights to SES so they had to avoid the country by beam management. If SES violates that Vietnam can sue them for interference. Forming the beam to comply happens to boost power available in other regions.

Does the countries adjacent to Vietnam also lose coverage as well?
If the map in the video is correct, Cambodia, Laos, and part of Thailand are also out of luck.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 01/22/2016 05:01 AM
i heard this launch got delayed from early Feb.?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: BrianNH on 01/22/2016 11:34 AM
Can you provide a source for that rumor?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 01/22/2016 01:21 PM
It's been Feb for a while. As noted, it's at least until after the Atlas V launch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 01/23/2016 12:38 PM
It's been Feb for a while. As noted, it's at least until after the Atlas V launch.

and when is the atlas V launch?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Toastmastern on 01/23/2016 12:47 PM
It's been Feb for a while. As noted, it's at least until after the Atlas V launch.

and when is the atlas V launch?

Feb 3 I believe
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ZachS09 on 01/23/2016 04:14 PM
At 8:47 AM EST. Refer to the thread about GPS IIF-12 for more info.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/23/2016 06:53 PM
So... The earliest launch date would be 2/5?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rockets4life97 on 01/24/2016 03:07 PM
Has there been confirmation that S1 and S2 for this launch are at the cape?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: saliva_sweet on 01/24/2016 04:54 PM
Has there been confirmation that S1 and S2 for this launch are at the cape?

No.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 01/24/2016 07:25 PM
Is there any word if the static fire will happen this week ?
The static fire must happen before the GPS launch if there's any hope of a launch very early Feb.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ChefPat on 01/25/2016 01:29 PM
i heard this launch got delayed from early Feb.?
I've seen Feb 6 from a couple of online sources. I'll take with a grain of salt until I see it here though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: manoweb on 01/25/2016 02:51 PM
Will this satellite need a specific window for its orbit or it can be launched at pretty much any time of the day?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 01/25/2016 03:02 PM
Will this satellite need a specific window for its orbit or it can be launched at pretty much any time of the day?

As I understand it, most Earth-orbiting satellites are launched to maximise the length of time they are over the day-side of Earth as soon as possible after S/C sep. This means that they get the maximum battery charge time on their solar arrays after the initial high-load events like the solar array and telemetry/command & control antenna deployment as well as possible main propulsion and RCS burns. This is why most spacecraft of this type are launched at night as S/C separation occurs shortly before orbital dawn.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Aerospace Dilettante on 01/25/2016 11:00 PM

As I understand it, most Earth-orbiting satellites are launched to maximise the length of time they are over the day-side of Earth as soon as possible after S/C sep. This means that they get the maximum battery charge time on their solar arrays after the initial high-load events like the solar array and telemetry/command & control antenna deployment as well as possible main propulsion and RCS burns. This is why most spacecraft of this type are launched at night as S/C separation occurs shortly before orbital dawn.

Yeah, if the apogee is occulted, up to 21% (worst case) of the orbital period will be in the dark.

Got this link from another thread:http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf (http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: yokem55 on 01/26/2016 10:15 PM
As the Atlas GPS launch has been delayed a few days, will SES-9 be delayed as well, or does SpaceX have an opportunity to get it's mission in early?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mleigh on 01/26/2016 10:48 PM
Does anyone know if the payload will be mated prior to the final static fire or if more time will be needed afterwards like Jason-3? NET Feb. 6th seems to be coming up fast considering I haven't heard confirmation of the stages arrival in FL nor about any cows running at McGregor recently.

(I'm pretty new to all of this so there's a chance I'm misunderstanding what a rocket does in the final weeks leading up to a launch.)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rocx on 01/26/2016 10:50 PM
Does anyone know if the payload will be mated prior to the final static fire or if more time will be needed afterwards like Jason-3? NET Feb. 6th seems to be coming up fast considering I haven't heard confirmation of the stages arrival in FL nor about any cows running at McGregor recently.

(I'm pretty new to all of this so there's a chance I'm misunderstanding what a rocket does in the final weeks leading up to a launch.)

It's a valid question, because it actually differs between providers and payloads. For this launch I'm pretty sure I've read that SES have agreed to conduct the static fire with their payload attached to the second stage, and this would save some time in the schedule.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: lbiderman on 01/27/2016 12:21 PM
Does anyone know if the payload will be mated prior to the final static fire or if more time will be needed afterwards like Jason-3? NET Feb. 6th seems to be coming up fast considering I haven't heard confirmation of the stages arrival in FL nor about any cows running at McGregor recently.

(I'm pretty new to all of this so there's a chance I'm misunderstanding what a rocket does in the final weeks leading up to a launch.)

It's a valid question, because it actually differs between providers and payloads. For this launch I'm pretty sure I've read that SES have agreed to conduct the static fire with their payload attached to the second stage, and this would save some time in the schedule.

That indeed is the case. SES has agreed to have the sat mated through static fire.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AndyX on 01/28/2016 01:20 PM
Per Chris's note.

Good enough to go in the update thread (but please copy to the other SES-9 threads):

There's industry level talk in L2 that points to this launch **possibly** moving to at least the second half of Feb. Totally unofficial, and it's always subject to change, but by now we should have info on "readiness days" for the Cape pads (which we get) and that provides a clue to milestones such as the Static Fire date. So the talk of it not being early Feb sounds like it has legs (no pun intended).

Of course, when I say "moving" to the right, there isn't an official launch date at this time (placeholder was Feb 6), so we'll see where this plays out. SpaceX don't provide running commentary on launch date targets, nor should they. Officially the path is after the Atlas V launch (which has also slipped a bit too - but that's not the impact on SES-9), but I wanted to pass on this info, regardless of it being unofficial, in case anyone has their browser open on BuyMeAPlaneTicketToNextSpaceXLaunch.com and was about to hit "purchase". ;)

When we know more I'll pass it on.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 01/28/2016 01:32 PM
"At least" the second half of February sounds like it could even slip into March.  With the backlog SpaceX has, there has to be a good reason they are considering pushing the launch this far out.  The satellite is clearly at the site and ready to go as far as we know, can't be a range thing with the date being possibly that far out, so most likely it is something on SpaceX's side.

Maybe the landing leg issue on Jason-3 has caused them to do some rework on the legs for the SES-9 flight.  Or maybe data review of the Orbcomm2 launch has revealed something they think needs to be addressed.  There were two open items mentioned in the USAF certification of "Falcon 9 Upgrade", maybe SpaceX wants to address one or both of those things immediately before moving forward...

All of this is total guesswork, of course.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 01/28/2016 01:37 PM
On the other hand, our ASDS spies indicate that the barge was taken out of Port Canaveral for a shake down cruise yesterday, with plans for another trip today.  So that might indicate that SpaceX are in fact gearing up for a near-term launch attempt.  *Might*.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Tonioroffo on 01/29/2016 08:39 PM
Something must be horribly wrong with the LV if Months of building up to RTF didn't make the issue show up?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 01/29/2016 10:23 PM
what percent chance could the slip mean theyre going to reuse the orbcomm stage for ses?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 01/29/2016 10:44 PM
what percent chance could the slip mean theyre going to reuse the orbcomm stage for ses?

My money is on "zero."
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: tleski on 01/29/2016 10:48 PM
what percent chance could the slip mean theyre going to reuse the orbcomm stage for ses?

I would say zero.
And as many people around here said before, it is a really good time to sign up for L2.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mader Levap on 01/29/2016 10:53 PM
On the other hand, our ASDS spies indicate that the barge was taken out of Port Canaveral for a shake down cruise yesterday, with plans for another trip today.  So that might indicate that SpaceX are in fact gearing up for a near-term launch attempt.  *Might*.
This does not indicate anything whatsoever. That launch slipped does not mean that shake down cruises would be also moved to right. Why they would be?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CraigLieb on 02/01/2016 02:06 PM
SpaceNews with the same situation. No one knows, not even SES - and SpaceX isn't talking about it.

http://spacenews.com/delays-in-spacex-falcon-9-upgrade-schedule-raises-concerns/

I thought that everybody else gets their information from reading NasaSpaceFlight.com update threads... ;-)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JamesH on 02/01/2016 03:46 PM
I wonder if the returned stage and subsequent test firing showed up some issues they need to fix, since it appeared the launch itself went quite well. Or perhaps a fix for the landing legs as shown up in the last landing attempt is taking a bit longer than expected.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: WBY1984 on 02/01/2016 04:02 PM
It sounds like something really serious is going on.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevinof on 02/01/2016 04:05 PM
That was my first thought a couple of days ago. Did they find something that they didn't like.

I don't think it's anything to do with the legs - they are only part of the secondary mission and doubtful they would delay a launch because of them.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Tuts36 on 02/01/2016 04:23 PM
That was my first thought a couple of days ago. Did they find something that they didn't like.


If they DID find a serious issue in the returned 1st stage, that would be quite interesting.  RTLS would have justified itself, even without reuse.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: francesco nicoli on 02/01/2016 04:36 PM
That was my first thought a couple of days ago. Did they find something that they didn't like.


If they DID find a serious issue in the returned 1st stage, that would be quite interesting.  RTLS would have justified itself, even without reuse.

Indeed. but still it's a worrysome development: it means the vector which should carry on most of 2016 launches is off the pad and the previous design is not in production any more.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: edkyle99 on 02/01/2016 04:48 PM
The January 30 photos of Falcon 9 stages on test stands at McGregor shows that SpaceX may be putting hardware into pre-flight qualification testing. 

 - Ed Kyle       
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/01/2016 05:11 PM
The January 30 photos of Falcon 9 stages on test stands at McGregor shows that SpaceX may be putting hardware into pre-flight qualification testing. 

 - Ed Kyle       

At least the first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 02/01/2016 06:58 PM
That was my first thought a couple of days ago. Did they find something that they didn't like.


If they DID find a serious issue in the returned 1st stage, that would be quite interesting.  RTLS would have justified itself, even without reuse.
That's my guess.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/01/2016 07:13 PM
That was my first thought a couple of days ago. Did they find something that they didn't like.

If they DID find a serious issue in the returned 1st stage, that would be quite interesting.  RTLS would have justified itself, even without reuse.

Unlikely. The stage went through another static fire.  Any issue affecting upcoming launches would have come forward before then and also could have affected the static fire.  Any issues after the static fire would more likely affect reuse vs first flight.   

And there are many other events that could have brought forward issues.  McGregor testing data review this launch or others could have uncovered some issues.  Even data review in the factory or engine testing for other mission could have uncovered issues.  Or even there could have been problems on Jason-3.   Or issues cleared for Jason-3 are still open for other missions. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/01/2016 07:17 PM
They may have had time to look at the struts (just an example, could be anything critical especially if on both stages) under a microscope. They may have found cracks where they expected none.

If it does have something to do with stuff they found on the returned first stage (doubtful), it will have proven the value of recovery.

But I suspect Jim is right.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 02/01/2016 08:48 PM
i was wondering if maybe some of the data from last launch's second stage mimiced some things from the second stage failure that they thought they had fixed.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/01/2016 09:37 PM
I would not be surprised if Elon tweets something about it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Brovane on 02/01/2016 09:46 PM
I would not be surprised if Elon tweets something about it.

In the words of Shotwell, Elon leans forward in his tweeting. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/02/2016 02:08 AM
i was wondering if maybe some of the data from last launch's second stage mimiced some things from the second stage failure that they thought they had fixed.

Indeed. Perhaps they've fixed a probable cause of S2 failure but now have better data.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 02/02/2016 02:15 AM
They may have had time to look at the struts (just an example, could be anything critical especially if on both stages) under a microscope. They may have found cracks where they expected none.

If it does have something to do with stuff they found on the returned first stage (doubtful), it will have proven the value of recovery.

But I suspect Jim is right.

Just talking about possibility here, but there can be issues you discover that will affect future flight, but won't affect a static fire.

Or, maybe something you find AFTER the static fire, telling you that you're one cycle away from a likely failure (remember also that the static fire was short, maybe cut short)

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Flying Beaver on 02/02/2016 02:24 AM
Is it possible (completely hypothetically) that SX is taking the extra time to get one of the OrbComm engines ready to be reflown on the SES-9 core? I.e after the static fire at SLC-40 they removed one of the fully functioning engines and shipped it back to McGregor for a full set of qualification tests. To then get it back to the cape for integration with the awaiting SES-9 stage.

This would add weeks onto the launch schedule but the chance to reuse one of the engine would be a major step towards reusability of the entire stage. Plus SX could pretty much guarantee a success having the ability to test the engine fully at McGregor.

But as I said, purely hypothetical.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Coastal Ron on 02/02/2016 02:44 AM
Is it possible (completely hypothetically) that SX is taking the extra time to get one of the OrbComm engines ready to be reflown on the SES-9 core?

Though SES has stated publicly that they would be interested in reusing the stage that lifts their upcoming SES-9 satellite, I don't think it's likely that they would be interested in delaying the revenue from SES-9 just so SpaceX can make the SES-9 flight more risky - SpaceX hasn't had enough time (or data) to make decisions about reusability yet, which means their customers don't have enough either.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/02/2016 03:04 AM
Is it possible (completely hypothetically) that SX is taking the extra time to get one of the OrbComm engines ready to be reflown on the SES-9 core? I.e after the static fire at SLC-40 they removed one of the fully functioning engines and shipped it back to McGregor for a full set of qualification tests. To then get it back to the cape for integration with the awaiting SES-9 stage.

This would add weeks onto the launch schedule but the chance to reuse one of the engine would be a major step towards reusability of the entire stage. Plus SX could pretty much guarantee a success having the ability to test the engine fully at McGregor.

But as I said, purely hypothetical.

*In the style of Jim*

No.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 02/02/2016 03:05 AM
Is it possible (completely hypothetically) that SX is taking the extra time to get one of the OrbComm engines ready to be reflown on the SES-9 core? I.e after the static fire at SLC-40 they removed one of the fully functioning engines and shipped it back to McGregor for a full set of qualification tests. To then get it back to the cape for integration with the awaiting SES-9 stage.

This would add weeks onto the launch schedule but the chance to reuse one of the engine would be a major step towards reusability of the entire stage. Plus SX could pretty much guarantee a success having the ability to test the engine fully at McGregor.

But as I said, purely hypothetical.

I don't think so, not even hypothetically.

Convincing a customer to take a risk on a launch is one thing.  Holding up an entire year's manifest for that?  nah.  There's always a next flight for that sort of experiment.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/02/2016 03:34 AM
i was wondering if maybe some of the data from last launch's second stage mimiced some things from the second stage failure that they thought they had fixed.

That's a good conjecture IMO. They probably instrumented/telemetered the heck out of the new S2, to verify the strut fix, gather data on other potential CRS-7 failure modes that they may have suspected but couldn't completely rule out, and monitor the effects of the S2 redesign. With all that telemetry there's a good chance they saw something they didn't like.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/02/2016 04:55 AM
I thought about that possibility, but AFAIK F9 v1.1 and v1.2 share the same strut design.  If Orbcomm showed strut issues, I can't imagine that Jason would have been allowed to launch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 02/02/2016 05:07 AM
*speculation zone* (top gun music blares)

perhaps they beefed up the struts but still showed an unexplained pressure spike. small leak from copv?

thatd be my first off-the-shelf pet theory

if they had some sort of microphone in the tank could they have heard a bubbling or fizzing sound?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CorvusCorax on 02/02/2016 08:23 AM
If I remember right there was an announcement during the last webcast (Jason) that there would be "no more inside views of the Falcon 9 in the webcasts" from then on

Would that be because SpaceX entirely removed the cameras from the tanks? Or because of secrecy/intellectual property concerns? (I think they were originally added to help resolve sloshing issues, but that too is speculation)

Could electronics in the tanks be a suspect to cause issues for some weird reason?

Then again, that was before the current delays became known, but maybe SpaceX already knew they had an issue when Jason launched? (If that's the case, then the problem would not affect v 1.1 though, which would rule out the camera as a potential cause)

The current lack of information is almost as frustrating as the delay itself.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Toastmastern on 02/02/2016 08:41 AM
If I remember right there was an announcement during the last webcast (Jason) that there would be "no more inside views of the Falcon 9 in the webcasts" from then on

I believe that had something to do with number of video feed they could use and SpaceX wanted to stream the videofeed from the barge instead of the tanks. But not sure.

//Toastmastern
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rocx on 02/02/2016 11:24 AM
Edit: add pdf on SES-9 & 10

Very interesting pdf! For example on page 14 there is the line "Fully reusable launch vehicles (Falcon 9-R) which amortises rocket costs over multiple missions" under the heading "Next next gen: 2019". I wonder if they mean upper stage reuse by that, how recent the information is, and if this takes into account the recent news about a Raptor Falcon upper stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/02/2016 01:13 PM
i was wondering if maybe some of the data from last launch's second stage mimicked some things from the second stage failure that they thought they had fixed.
That's a good conjecture IMO. They probably instrumented/telemetered the heck out of the new S2, to verify the strut fix, gather data on other potential CRS-7 failure modes that they may have suspected but couldn't completely rule out, and monitor the effects of the S2 redesign. With all that telemetry there's a good chance they saw something they didn't like.
This fits the timescale and lack of comments very well.  For example, they might find some case where they thought they had 40% margin, but telemetry showed only 10% (numbers obviously made up).  Now they need to re-design the bracket/fitting/plate/whatever, build a new set of them, install them in the S2 they already built (which might be tedious, depending on the part), and perhaps test them in a complete stage to make sure (a) the fix works, and (b) there are no un-intended consequences.  This is a serial process (design, build, install, test) and could easily take a month or two. 

This is business as usual for the first test of a new or modified design, with no long term consequences to the production rate, performance, or cost,  so no need to make any public clarification or announcement.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/02/2016 02:37 PM
**** speculations ****

Supercooled kerosene will solidify much faster than regular kerosene - maybe the issue is with max time that second stage can handle? It would not be an issue with Orbcomm as tests were performed imidiately after releasing sateliites, but may be a major issue when flying to GTO with long coast phase.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: wolfpack on 02/02/2016 02:42 PM

That's a good conjecture IMO. They probably instrumented/telemetered the heck out of the new S2, to verify the strut fix, gather data on other potential CRS-7 failure modes that they may have suspected but couldn't completely rule out, and monitor the effects of the S2 redesign. With all that telemetry there's a good chance they saw something they didn't like.

If that's the case, then I'd expect the helium bottles to come out of the LOX tank and S2 would look a lot more like its contemporary counterparts. That sort of redesign would shift schedules to the right.

Speculation, of course. We'll know when Elon tweets or there's a press release.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mheney on 02/02/2016 04:45 PM
**** speculations ****

Supercooled kerosene will solidify much faster than regular kerosene - maybe the issue is with max time that second stage can handle? It would not be an issue with Orbcomm as tests were performed imidiately after releasing sateliites, but may be a major issue when flying to GTO with long coast phase.

You super-cool the kerosene (and the LOX) to increase it's density, allowing you to increase the mass of propellants in a given-sized tank.  For the second stage, you're going to light it up immediately after first stage sep, and consume enough propellant so that density won't be an issue - the tank will be partially empty at the conclusion of the burn.  The kerosene can be permitted to warm up with no real issue.  The LOX needs to be kept cool enough to stay liquid ...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/02/2016 04:58 PM
Propellant densification is only used on the first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/02/2016 05:06 PM
Propellant densification is only used on the first stage.
Pretty sure you are wrong.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/02/2016 05:40 PM
The kerosene can be permitted to warm up with no real issue

So you need kerosene heater - does second stage have something like that?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mheney on 02/02/2016 05:58 PM
The kerosene can be permitted to warm up with no real issue

So you need kerosene heater - does second stage have something like that?

Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: [email protected] on 02/02/2016 07:05 PM
Any possibility that mission delay is related because landing leg didn't "click" on last landing, so SX is making some changes?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/02/2016 07:50 PM
Any possibility that mission delay is related because landing leg didn't "click" on last landing, so SX is making some changes?

No

Non-Jim Mode:  They have aid they don't delay paying missions for landing issues.
We were also told that the leg is not the specific issue.
There were also statements that the issue with the leg on the Jason flight had to do with the humid environment in CA.

edit:  We were all urged NOT to speculate.  We will learn the reason for the delay when we are told, or we won't learn at all.  Can we all just "hold our horses"?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Norm Hartnett on 02/02/2016 11:55 PM
<snip>
edit:  We were all urged NOT to speculate.  We will learn the reason for the delay when we are told, or we won't learn at all.  Can we all just "hold our horses"?

Wait, what? That would not be in the finest traditions of NSF I believe.

[mindless speculation]

Given that they have had time to closely examine their first RTLS first stage I would mindlessly speculate that they found something they didn't expect. Possibly unexpected physical materials damage from exposure to very low temp LOX?

[/mindless speculation]
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AS-503 on 02/03/2016 12:14 AM
<snip>
edit:  We were all urged NOT to speculate.  We will learn the reason for the delay when we are told, or we won't learn at all.  Can we all just "hold our horses"?

Wait, what? That would not be in the finest traditions of NSF I believe.

[mindless speculation]

Given that they have had time to closely examine their first RTLS first stage I would mindlessly speculate that they found something they didn't expect. Possibly unexpected physical materials damage from exposure to very low temp LOX?

[/mindless speculation]

Jim already wrote a very good post two pages back (Reply #353) that logically suggests that the hold is highly unlikely to be related to the first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: spacenut on 02/03/2016 12:50 AM
Yep, they really haven't had any problems with the first stage other than landing legs.  From what everyone said, it is either a problem with the second stage or the payload.  Hope they can get it resolved quickly. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: psionedge on 02/03/2016 12:56 AM
SpaceNews article in the updates thread says SES says it's not the payload, and SpaceX hasn't told them a reason for the delay.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/03/2016 01:14 AM
Yep, they really haven't had any problems with the first stage other than landing legs.  From what everyone said, it is either a problem with the second stage or the payload.  Hope they can get it resolved quickly.

What about something arising out of the investigation into the "thrust fluctuations" during the static fire of the landed stage?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: su27k on 02/03/2016 01:41 AM
Any possibility that mission delay is related because landing leg didn't "click" on last landing, so SX is making some changes?

No

Non-Jim Mode:  They have aid they don't delay paying missions for landing issues.
We were also told that the leg is not the specific issue.
There were also statements that the issue with the leg on the Jason flight had to do with the humid environment in CA.

The issue may not be the leg, but it could be informed by the leg issue. Having moving part icing over may raise some concerns about other moving parts.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/03/2016 01:57 AM

Jim already wrote a very good post two pages back (Reply #353) that logically suggests that the hold is highly unlikely to be related to the first stage.

No, I said it was unlikely that issue was found by examining the returned stage. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 02/03/2016 06:19 AM
Propellant densification is only used on the first stage.
Pretty sure you are wrong.

What I do know is that densification reduces Isp, since the heat of formation is reduced due to the colder temperatures. On the first stage, the increased propellant mass dominates the performance loss of the Isp. For the upper stage, the question is does the saving in tank mass make up for the loss in Isp? I suspect not, and considering that SpaceX did lengthen the tank, I suspect the second stage does not use propellant densification.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/03/2016 12:34 PM
Propellant densification is only used on the first stage.
Pretty sure you are wrong.

What I do know is that densification reduces Isp, since the heat of formation is reduced due to the colder temperatures. On the first stage, the increased propellant mass dominates the performance loss of the Isp. For the upper stage, the question is does the saving in tank mass make up for the loss in Isp? I suspect not, and considering that SpaceX did lengthen the tank, I suspect the second stage does not use propellant densification.
Engineering is done with numbers, so let's guess.  Start with a same size tank.  LOX that is 24 K colder (66 vs 90) will take 24*1.7 = 41 KJ/kg more to warm it. With a mixture ratio of 2.56, 1 kg of LOX combines with 391 grams of kerosene to generate 16.80 MJ of energy.  So the energy content, per kg, goes down by 0.24%. 

But pumps that pump liquid pump by volume, not mass.  So at the same (liquid) flow rate, you have about 6% more mass going into the chamber per sec (since the subcooled LOX is denser).  So to first order, the chamber pressure should go up by about 5.8%, leading to better ISP.

Furthermore, the mass fraction also goes up (more LOX in the same mass of tank).  And if both the mass fraction and ISP go up, so must performance.

This all assume the tank size and the turbopump speed are unchanged.  The second stage tank stretch should improve mass fraction as well (the new wall mass should be proportional the contained mass, and the other masses - engines, aviionics, etc are unchanged).  And the turbopump speed seems increased as well - the full thrust engine (booster) burns through a tank in 160 seconds instead of 182.  This too will increase the chamber pressure, and hence ISP.

So for sure the second stage would get higher performance with sub-cooled LOX.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/03/2016 02:15 PM
Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.

I may be wrong but kerosene going solid was the main reason F9 second stage could not do long duration satellite deployments in the past. Subcooled kerosene may only amplify this issue.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mheney on 02/03/2016 02:51 PM
Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.

I may be wrong but kerosene going solid was the main reason F9 second stage could not do long duration satellite deployments in the past. Subcooled kerosene may only amplify this issue.

The kerosene is cooled to 20F (-7C) according to a quick look on Wikipedia (sorry...)  So if solidification were an issue, it would happen a bit quicker if you started with chilled RP-1.  But I'm not seeing any indication that that was a concern.  My understanding (which could be in error) was that keeping cryo fluids like LOX liquid was the major concern.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/03/2016 02:57 PM
Propellant densification is only used on the first stage.
Pretty sure you are wrong.

What I do know is that densification reduces Isp, since the heat of formation is reduced due to the colder temperatures. On the first stage, the increased propellant mass dominates the performance loss of the Isp. For the upper stage, the question is does the saving in tank mass make up for the loss in Isp? I suspect not, and considering that SpaceX did lengthen the tank, I suspect the second stage does not use propellant densification.
The reduction in Isp (which presupposes they're energy limited, but they aren't since they still run significantly fuel-rich) is not significant enough to matter even for the upper stage. The reason they're going for lengthening is that the second stage is much smaller anyway and the propellants would warm to a variable degree in the way up, and it can't afford to be venting liquid like you can wen you're sitting on the pad being replenished.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kansan52 on 02/03/2016 03:21 PM
Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.

I may be wrong but kerosene going solid was the main reason F9 second stage could not do long duration satellite deployments in the past. Subcooled kerosene may only amplify this issue.

If memory serves, the problem was the first F1.1 launch and a fuel line froze. The solution was (again, if memory serves) rerouting the line and more insulation.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MattMason on 02/03/2016 03:36 PM
As a certain legendary flight director said, "Let's keep it cool, people."

No matter what is going on, note that SpaceX discovered a potential issue between flights and (thank goodness) not through an active mission through a RUD or other LOV.

They lose nothing but a little time to ensure things go right. This whole delay is a positive; it may show that their internal checks after CRS-7 are catching and correcting critical issues before a flight that could cause payload issues or worse.

Speculation is fun, but baseless speculation is for other "news" sites. Let's keep our NSF standard for informed speculation. Even a mere enthusiast like me can smell something wrong in the recent posts, and it's not rocket cows.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cambrianera on 02/03/2016 03:41 PM
Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.

I may be wrong but kerosene going solid was the main reason F9 second stage could not do long duration satellite deployments in the past. Subcooled kerosene may only amplify this issue.

If memory serves, the problem was the first F1.1 launch and a fuel line froze. The solution was (again, if memory serves) rerouting the line and more insulation.

Quite,  it was a TEA-TEB line.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kansan52 on 02/03/2016 03:54 PM
Between sunshine and earthshine, it'll warm up just fine on it's own.  No heaters needed.

I may be wrong but kerosene going solid was the main reason F9 second stage could not do long duration satellite deployments in the past. Subcooled kerosene may only amplify this issue.

If memory serves, the problem was the first F1.1 launch and a fuel line froze. The solution was (again, if memory serves) rerouting the line and more insulation.

Quite,  it was a TEA-TEB line.

Thanks!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: e of pi on 02/03/2016 06:08 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
Is that related to the SES-9 launch, or just in general?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kryten on 02/03/2016 06:14 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
Is that related to the SES-9 launch, or just in general?
She didn't clarify in the talk what the timeframe of these mods are, so could be either.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mongo62 on 02/03/2016 06:15 PM
Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevinof on 02/03/2016 06:17 PM
No doubt some extra thermal blankets - hopefully nothing more than that.

From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."

Better thermal protection on some exposed sensitive bits?  And a fire extinguisher?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mme on 02/03/2016 06:21 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
So I guess getting back your engines for inspection and testing is useful to the engineering endeavor.  Who would of thunk? ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: russianhalo117 on 02/03/2016 06:36 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
Is that related to the SES-9 launch, or just in general?
indirectly related yes, since SES told SpaceX that they want to fly another satellite on the SES-9 booster this/next year if it is successfully recovered. SES and SpaceX signed some deals/agreements about this when they signed to fly SES-9 and signed an amendment when the launch switched versions to the F9 Upgrade (formerly called F9 FT)

corrected typo
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/03/2016 07:15 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
Is that related to the SES-9 launch, or just in general?
Directly related yes, since SES told SpaceX that they want to fly another satellite on the SES-9 booster this/next year if it is successfully recovered. SES and SpaceX signed some deals/agreements about this when they signed to fly SES-9 and signed an amendment when the launch switched versions to the F9 Upgrade (formerly called F9 FT)

That is an *indirect* link, not a direct link. There is not enough context to determine if Shotwells answer applies to the SES-9 delays. SpaceX continually refines/modifies F9.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/03/2016 07:28 PM
Yes, I see some confusion over that. The only direct SES-9 reference is the plan to launch in a few weeks. Ms. Shotwell was talking about a lot of things inbetween...from FH to landings.

So that recovered booster references should continue in the relevant threads and let's keep this on SES-9.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/03/2016 08:15 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
So I guess getting back your engines for inspection and testing is useful to the engineering endeavor.  Who would of thunk? ;)

Not necessarily the correct takeaway. It may just relate to reuse and not first flight
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Proponent on 02/03/2016 08:53 PM
What I do know is that densification reduces Isp, since the heat of formation is reduced due to the colder temperatures. On the first stage, the increased propellant mass dominates the performance loss of the Isp. For the upper stage, the question is does the saving in tank mass make up for the loss in Isp? I suspect not, and considering that SpaceX did lengthen the tank, I suspect the second stage does not use propellant densification.

Jim has told us that the RP-1 on the Delta II's first stage is heated (http://forum.nasaspaceflight.com/index.php?topic=5118.msg81581#msg81581) to improve performance.  Since so much of Delta II's take-off thrust is generated by its solids, the "first" stage is somewhat akin to a second stage.  That tends to confirm your suspicion that F9's second-stage propellants are not densified.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Proponent on 02/03/2016 09:08 PM
Engineering is done with numbers, so let's guess.  Start with a same size tank.  LOX that is 24 K colder (66 vs 90) will take 24*1.7 = 41 KJ/kg more to warm it. With a mixture ratio of 2.56, 1 kg of LOX combines with 391 grams of kerosene to generate 16.80 MJ of energy.  So the energy content, per kg, goes down by 0.24%.

But pumps that pump liquid pump by volume, not mass.  So at the same (liquid) flow rate, you have about 6% more mass going into the chamber per sec (since the subcooled LOX is denser).  So to first order, the chamber pressure should go up by about 5.8%, leading to better ISP.

Furthermore, the mass fraction also goes up (more LOX in the same mass of tank).  And if both the mass fraction and ISP go up, so must performance.

This all assume the tank size and the turbopump speed are unchanged.  The second stage tank stretch should improve mass fraction as well (the new wall mass should be proportional the contained mass, and the other masses - engines, aviionics, etc are unchanged).  And the turbopump speed seems increased as well - the full thrust engine (booster) burns through a tank in 160 seconds instead of 182.  This too will increase the chamber pressure, and hence ISP.

So for sure the second stage would get higher performance with sub-cooled LOX.

I have two comments, which go in opposite directions.  One is that a propellant sub-cooled by a certain amount in the tank will be less sub-cooled by the time it reaches the combustion chamber.  Being colder than a non-sub-cooled propellant to begin with, it will warm up faster than a non-sub-cooled propellant.  Hence, the effects of sub-cooling, aside from greater storage density, will be a little less than it would seem at first glance.

Secondly, though, increasing density will increase the mass of the second stage.   The extent to which that extra mass hurts performance will depend on the mission.  If it's launch a heavy payload to a low orbit, the mass will hurt less than if it's a light payload going to a higher-energy trajectory.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MrHollifield on 02/03/2016 10:30 PM
IIRC, the OrbComm 2 S2 was still loading propellants at under 3 min to launch. The only reason I can think of to be loading (not topping) that late in the count is if you are loading subcooled liquids and want to reduce warming and thermal expansion during S1 flight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: The Amazing Catstronaut on 02/03/2016 11:18 PM
Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.

That's a mental launch cadence - Shotwell also tends to be more conservative in her estimates than Elon. Are there any visible signs they're ready to do this after SES-9?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/03/2016 11:27 PM
Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.

That's a mental launch cadence - Shotwell also tends to be more conservative in her estimates than Elon. Are there any visible signs they're ready to do this after SES-9?

I'm not sure you realize how imprecise "every few weeks" is. Could be two weeks apart. Or eight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/04/2016 12:18 AM
Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.

That's a mental launch cadence - Shotwell also tends to be more conservative in her estimates than Elon. Are there any visible signs they're ready to do this after SES-9?

I'm not sure you realize how imprecise "every few weeks" is. Could be two weeks apart. Or eight.

hmm, in common use if you say every few weeks  you mean more often than once a month.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/04/2016 12:51 AM
A few posts made reference to Shotwell's talk:


Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.
Here's the
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
Is that related to the SES-9 launch, or just in general?
She didn't clarify in the talk what the timeframe of these mods are, so could be either.


Here's a link to Shotwell's talk:
She's on at 2:43:00
https://www.youtube.com/watch?v=2cT7_iySwP8
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ZachS09 on 02/04/2016 03:39 AM
Thank you, Ms. Shotwell, for finally breaking the news! We all appreciate your willingness to give us what we wanted!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Beittil on 02/04/2016 07:36 AM
Jeff Foust ‏@jeff_foust  13m13 minutes ago
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.

That's a mental launch cadence - Shotwell also tends to be more conservative in her estimates than Elon. Are there any visible signs they're ready to do this after SES-9?

I'm not sure you realize how imprecise "every few weeks" is. Could be two weeks apart. Or eight.
Hmm, I would categorize "every few weeks" to be at minimum 2 weeks and at maximum 3 weeks. Anything more than that and she might as well have said 'at least once per month'.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/04/2016 08:56 AM
As for trying to determine what “a few weeks” means....

Overanalysis.  Trying to translate into a specific number range,  for a term that  was very likely stated in a manner to be intentionally non-specific  to begin with.

- George Gassaway
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 02/04/2016 09:30 AM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."

Better thermal protection on some exposed sensitive bits?  And a fire extinguisher?

I remember Elon Tweeting something about there being a thrust anomaly in one of the engines during the re-fire that made them cut it short. It's possible that they've had to tweak some of the components in the engines to better handle repeated thrust/cool down cycles with minimal maintenance. Remember, the ultimate objective of the program is a stage that can be turned around in hours so they want the vehicle to need minimal maintenance during routine ops.

I'm guessing that we're looking at a 2-4 week production break as they replaced the turbine blades in the turbo-impellers or maybe the fuel valves in all the Merlin-1ds on the line and awaiting testing. This would consequently lead to delays of a similar length at every step of the production and testing flow.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JamesH on 02/04/2016 10:43 AM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."

Better thermal protection on some exposed sensitive bits?  And a fire extinguisher?

I remember Elon Tweeting something about there being a thrust anomaly in one of the engines during the re-fire that made them cut it short. It's possible that they've had to tweak some of the components in the engines to better handle repeated thrust/cool down cycles with minimal maintenance. Remember, the ultimate objective of the program is a stage that can be turned around in hours so they want the vehicle to need minimal maintenance during routine ops.

I'm guessing that we're looking at a 2-4 week production break as they replaced the turbine blades in the turbo-impellers or maybe the fuel valves in all the Merlin-1ds on the line and awaiting testing. This would consequently lead to delays of a similar length at every step of the production and testing flow.

It was possibly due to foreign object ingestion causing thrust fluctuations. That could mean something picked up during the landing, or something came loose earlier in the flight, perhaps in ascent.

If in flight, could be anything in the fuel path coming adrift. Clearly not a common fault, or we would have seen it already, (20 flights x 9 engines, and it didn't actually fail this time). But also, clearly worth fixing.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/04/2016 11:17 AM
Thank you, Ms. Shotwell, for finally breaking the news! We all appreciate your willingness to give us what we wanted!

She never stated that it was the reason for the delay
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Shanuson on 02/04/2016 11:49 AM
A few posts made reference to Shotwell's talk:
Here's a link to Shotwell's talk:
She's on at 2:43:00
https://www.youtube.com/watch?v=2cT7_iySwP8

Is there a none youtube version of this video? Can't watch it in Germany due to GEMA-Youtube-payment-dispute. The Shotwell part would be enough :D

Cheers
Shanuson
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 02/04/2016 12:47 PM
A few posts made reference to Shotwell's talk:
Here's a link to Shotwell's talk:
She's on at 2:43:00
https://www.youtube.com/watch?v=2cT7_iySwP8

Is there a none youtube version of this video? Can't watch it in Germany due to GEMA-Youtube-payment-dispute. The Shotwell part would be enough :D

Cheers
Shanuson

have you tried a web proxy and if those dont work then download the TOR browser.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/04/2016 01:19 PM
Question: can increased G loads near stage burnout adversely affect turbopumps, in particular the shaft and bearings as the load on one end (assuming vertical mount) is effectively ~4x higher than what can be replicated on the ground?

It occurs to me the 9 M1Ds returned would be the first ever hardware SpaceX has seen that actually went through such a load cycle, regardless of how many seconds of ground test data they have. The 2nd stage engine, given longer burn durations and comparatively longer exposures to higher Gs might make it even more susceptible to such effects, if any. Then again, one might think any potential findings after OG2 static fire could have potentially grounded Jason-3 as well - which they didn't.

Thoughts?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Norm38 on 02/04/2016 01:27 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
So I guess getting back your engines for inspection and testing is useful to the engineering endeavor.  Who would of thunk? ;)

Not necessarily the correct takeaway. It may just relate to reuse and not first flight

Shotwell did say in her talk, at 2:54:15, "we learned something, and will make the vehicle even more robust for the ascent portion".

Doesn't necessarily mean it caused the delay, but it does sound to me like it would be relevant for first flight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kim Keller on 02/04/2016 02:30 PM
IIRC, the OrbComm 2 S2 was still loading propellants at under 3 min to launch. The only reason I can think of to be loading (not topping) that late in the count is if you are loading subcooled liquids and want to reduce warming and thermal expansion during S1 flight.

Correct.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/04/2016 02:32 PM
I'm convinced, then. :)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/04/2016 02:45 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."
So I guess getting back your engines for inspection and testing is useful to the engineering endeavor.  Who would of thunk? ;)

Not necessarily the correct takeaway. It may just relate to reuse and not first flight
Gwynne explicitly said these were improvements that would benefit first flight.

EDIT: @Norm38 beat me to this, and he's got the exact quote.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/04/2016 03:08 PM
Based on the Shotwell comment, it seems safe to say that SpaceX, at least, thinks that they learned something about the ability of the F9FT to perform its primary mission, from the recovered stage.

Who'd a thunk it?

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Port on 02/04/2016 03:11 PM
A few posts made reference to Shotwell's talk:
Here's a link to Shotwell's talk:
She's on at 2:43:00
https://www.youtube.com/watch?v=2cT7_iySwP8

Is there a none youtube version of this video? Can't watch it in Germany due to GEMA-Youtube-payment-dispute. The Shotwell part would be enough :D

Cheers
Shanuson

have you tried a web proxy and if those dont work then download the TOR browser.
or the proxy-flow addon (chrome, but i guess firefox has it too?)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: leaflion on 02/04/2016 03:19 PM
From Twitter user @flatoday_jdean
"Shotwell: SpaceX making F9 mods based on lessons learned from re-firing the recovered booster's engines."

Better thermal protection on some exposed sensitive bits?  And a fire extinguisher?

I remember Elon Tweeting something about there being a thrust anomaly in one of the engines during the re-fire that made them cut it short. It's possible that they've had to tweak some of the components in the engines to better handle repeated thrust/cool down cycles with minimal maintenance. Remember, the ultimate objective of the program is a stage that can be turned around in hours so they want the vehicle to need minimal maintenance during routine ops.

I'm guessing that we're looking at a 2-4 week production break as they replaced the turbine blades in the turbo-impellers or maybe the fuel valves in all the Merlin-1ds on the line and awaiting testing. This would consequently lead to delays of a similar length at every step of the production and testing flow.

One does not merely "replace the turbine blades."

You have do delta qual testing of the engine after that before you fly it again.  No change is a small change, and you may completely screw up your engine doing that.

I also imagine their goal is to first at least be able to refly a stage before worrying about hours long turnaround.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: toruonu on 02/04/2016 06:17 PM
Here's a link to Shotwell's talk:
She's on at 2:43:00
https://www.youtube.com/watch?v=2cT7_iySwP8

I looked at that and from the moment she stepped on podium until she left and I didn't hear the part where she mentions flying SES-9 in two weeks. Can someone point me the timecode or how did people come to the conclusion. She did mention schedule cadence and plans to reach a launch a week or multiple per week even in the future, but that's all there was to launch cadence...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/04/2016 06:24 PM
I looked at that and from the moment she stepped on podium until she left and I didn't hear the part where she mentions flying SES-9 in two weeks.
Quote
Shotwell said after her talk SpaceX planning to launch SES-9 in next couple of weeks, then do launches every few weeks thereafter this year.
Source: https://twitter.com/jeff_foust/status/694959022877863936
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hrissan on 02/04/2016 06:28 PM
Question: can increased G loads near stage burnout adversely affect turbopumps, in particular the shaft and bearings as the load on one end (assuming vertical mount) is effectively ~4x higher than what can be replicated on the ground?

It occurs to me the 9 M1Ds returned would be the first ever hardware SpaceX has seen that actually went through such a load cycle, regardless of how many seconds of ground test data they have. The 2nd stage engine, given longer burn durations and comparatively longer exposures to higher Gs might make it even more susceptible to such effects, if any. Then again, one might think any potential findings after OG2 static fire could have potentially grounded Jason-3 as well - which they didn't.

Thoughts?
The returning stage experiences ~10g during the entrance burn... This should be ok for loads on tank walls and thrust structure (no 100-ton 2nd stage above), but some small piece of hardware like a GoPro camera or sensor mount might break lose from inside of the tank @10g plus hectic vibrations - hence foreign object ingestion in later tests.

***Blatant IMHO above
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/04/2016 07:02 PM
Even if the g load is higher during max Q on the way down, the turbopumps are not spinning at that point so that doesn't necessarily mean the same kind of wear, hence my question about loads during powered flight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cambrianera on 02/04/2016 08:10 PM
Even if the g load is higher during max Q on the way down, the turbopumps are not spinning at that point so that doesn't necessarily mean the same kind of wear, hence my question about loads during powered flight.

Sometimes you can have more damage loading a static (non rotating) bearing than a rotating one.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Fan Boi on 02/04/2016 08:40 PM
Especially a plane bearing with no oil pressure, it even has more "slack" to move around and potentially touch the housing (although it likely isn't spinning). A turbopump that is pumping liquid stops very quickly when powered off.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ogiw on 02/04/2016 11:24 PM
I don't think we should discount the possibility that something at the base of the vehicle was damaged by the hypersonically-heated slipstream. 

I do in fact understand that the base of a Falcon 9 gets a bit balmy during liftoff.   ;)

However, this is returning bass-ackwards and is the first that they recovered in more-or-less intact fashion.

This would be congruent with Shotwell's comments about increasing the robustness of the vehicle during ascent.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: iamlucky13 on 02/05/2016 11:02 PM
A related thought I've been toying with is the fact that most aluminum alloys are pretty heat sensitive. Yield strength drops fast as the temperature goes up. This affect applies to some degree to all metals, but aluminum in particular. You can see some data points here:
http://www.matweb.com/search/datasheet_print.aspx?matguid=1b8c06d0ca7c456694c7777d9e10be5b

Yield strength at 400 degrees F is only 3/8 that at room temperature. This is one of the most conventional aluminum alloys. It's worse for the really high strength stuff.

It's worse for higher strength alloys (although note this spec sheet uses long term data that would be affected by creep effects, it's not entirely comparable):
http://matweb.com/search/DataSheet.aspx?MatGUID=9852e9cdc3d4466ea9f111f3f0025c7d
1/4 of room temperature strength when heated to 350 degrees F.

If there is worse heating flying into the plume during landing, it's conceivable SpaceX may need to make some modifications to deal with that heating better.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lee Jay on 02/06/2016 12:19 AM
I don't think we should discount the possibility that something at the base of the vehicle was damaged by the hypersonically-heated slipstream. 

Even though Elon stated that inspection found no damage?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AncientU on 02/06/2016 12:31 AM
I don't think we should discount the possibility that something at the base of the vehicle was damaged by the hypersonically-heated slipstream. 

Even though Elon stated that inspection found no damage?

He also stated that they would scope the engine that displayed flow instabilities.
Nothing much has been said since then.  My vote is for finding something in that engine that came from inside the tank as suggested/implied by hrissan above.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/06/2016 06:09 AM
Even though Elon stated that inspection found no damage?

Elon Musk is not omniscient, he is a human.  He only knows what he knows (plus what he’s told).

A  relatively quick, less than thorough, examination does not mean there was not any damage.

Just they had not found anything (yet). 

If a person who cannot communicate  sees a  doctor for a 10 minute checkup and the doctor finds no obvious problem, does not mean they may not have some serious medical issue lurking.  It would require more thorough procedures to declare that they are 100% healthy and disease-free.  Blood tests of all kinds, thousands of $ of medical tests to rule out all possibilities that can be tested for, MRI, cancer screening, etc.  Including exploratory surgery.

Extreme, yes. But short of doing that, a 10 minute check-up that finds nothing wrong…. does not mean there is not something wrong…. just  that nothing was found. I liken the F9 core’s post-landing inspection to a 10 minute doctor’s check-up of a patient who cannot communicate that anything "feels" unusual.

That F9 core won’t really get totally thorough inspections until it gets to Hawthorne and they strip it down as much as necessary (I suspect one reason Musk said it probably will not fly again may not be just for sentimental/historic reasons. But that some of the truly thorough inspections may involve cutting into it to get  to all the places they may need to, like exploratory surgery. In which case it could tend to be ruined for re-flight but still fine for a museum).

The fact that one engine had a problem worthy of causing an early shutdown for the brief static test tends to imply that the cause was  some sort of damage which the early inspection was not able to find (but of course that is not a certainty. Just that declaring “no damage”, and later an engine with a problem, seem to be in disagreement).

- George Gassaway
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/06/2016 03:36 PM
I am a little surprised they fired  all off the engines at once. I would have thought they would fire them all individually for a few seconds, and then fire the cluster. May be that this in logistically or functionally not possible?

Matthew
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 02/06/2016 07:42 PM
I am a little surprised they fired  all off the engines at once. I would have thought they would fire them all individually for a few seconds, and then fire the cluster. May be that this in logistically or functionally not possible?

Matthew
They can afford to take risks with this stage. It will never be launched again, has been fully paid for and additional recovered stages are (relatively) around the corner. Besides, SpaceX is famous for making bold gambles.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/06/2016 07:51 PM
They can afford to take risks with this stage.

I am reasonably sure they would not like to blow up LC-40 with that test. So they really did anticipate that not to happen.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/06/2016 07:54 PM
They can afford to take risks with this stage.

I am reasonably sure they would not like to blow up LC-40 with that test. So they really did anticipate that not to happen.
Or they anticipated they could shut it down if there was a problem, which is exactly what happened.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/07/2016 12:14 AM
I am a little surprised they fired  all off the engines at once. I would have thought they would fire them all individually for a few seconds, and then fire the cluster. May be that this in logistically or functionally not possible?

Matthew
They can afford to take risks with this stage. It will never be launched again, has been fully paid for and additional recovered stages are (relatively) around the corner. Besides, SpaceX is famous for making bold gambles.
Yup. And ...

How else do you find out how effective it would be in being reused? Isn't that the point of the vehicle?

Also, Shotwell occasionally remarks on Musk's penchant for collecting SX flight test vehicles for posterity ... ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/08/2016 08:04 AM
Launch announcement for Feb. 24 according to this article.

https://uk.finance.yahoo.com/news/ses-9-launch-targeting-february-080000051.html

To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt. Good move.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/08/2016 09:05 AM
To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt.

The cynic in me is wondering whether the F9FT performance is less than expected, precluding the original nominal mission *and* barge landing so SpaceX just went ahead and committed all of the recovery reserve to SES-9.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jet Black on 02/08/2016 09:56 AM
To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt.

The cynic in me is wondering whether the F9FT performance is less than expected, precluding the original nominal mission *and* barge landing so SpaceX just went ahead and committed all of the recovery reserve to SES-9.

There is no reason to think that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: DanseMacabre on 02/08/2016 12:14 PM
Launch announcement for Feb. 24 according to this article.

https://uk.finance.yahoo.com/news/ses-9-launch-targeting-february-080000051.html

To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt. Good move.

I followed up with James Dean of FL today to confirm his note in his article that a landing would still be attempted; He needs to follow up and confirm no change to recovery ops. Link to thread here: https://twitter.com/flatoday_jdean/status/696682913425973248
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 02/08/2016 01:10 PM
Space News article on the SES press release:

http://spacenews.com/ses-we-plan-feb-24-spacex-launch-of-ses-9-satellite/ (http://spacenews.com/ses-we-plan-feb-24-spacex-launch-of-ses-9-satellite/)

Quote
“SpaceX is currently completing an extended series of testing and pre-flight validation in advance of the SES-9 launch,” SES said.

Is that the explanation for the SES delays, a new flight profile require new testing?

FWIW, my gut feeling is that it was something hardware-related.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 02/08/2016 01:43 PM
To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt.

The cynic in me is wondering whether the F9FT performance is less than expected, precluding the original nominal mission *and* barge landing so SpaceX just went ahead and committed all of the recovery reserve to SES-9.

Less than expected by whom? The original nominal mission was a sub-synchronous expendable insertion with v1.1. One month after that, it changed to a sub-synchronous DPL insertion with FT. FT has never been advertised to send a 5,300kg sat to GTO-1800 and then do a DPL. They actually list far less on their website (assuming the max they do list is for a DPL profile).

My take on this is that SES and SpaceX decided to go for a super-synchronous expendable mission profile so as to have the satellite come online sooner than expected, thus offsetting the delays that have plagued this campaign.

It's a good decision for business imo, although less exciting for SpaceX fans (that want to see the company nail its first FT barge landing sooner rather than later).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jarnis on 02/08/2016 01:53 PM
I also assume this may be expendable, but... who knows. Maybe they have really sandbagged the FT numbers and they'll pull off a supersynch insertion *with* (far downrange) barge recovery...

Will be interesting to see first pics. Basically if there are no legs during Static Fire, we will immediately know the barge will be staying home.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/08/2016 01:55 PM
Also possible that SpaceX identified some landing leg fixes they want to implement, and decided it was best to wait and implement them instead of torching another barge with an attempt which their revised modeling indicates is likely to fail.  If that also makes the customer happy, then win win win.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/08/2016 01:56 PM
If there will be a recovery attempt, I wonder just how far downrange the ASDS will have to be towed for what I'd guess is basically a ballistic trajectory.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/08/2016 02:14 PM
It looks like I might be in Florida during this launch, so I'm also very curious about what a far-downrange recovery attempt will look like from a viewing point at the cape.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/08/2016 02:22 PM
Seems like there are two options: #1 (most likely) it's going to be an expendable flight.  #2 (possible) they will attempt a two-burn profile... completely eliminating the boost-back burn, and instead just conducting the supersonic re-entry burn... and the landing burn.

Eliminating the boost-back burn would allow around 10s more of full-thrust flight, with the rocket very light at that point due to mostly depleted 1st stage tank.  No idea how much dV that would account for at that point in the flight.

My gut feeling is that they're just going to splash the stage, but we will see.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/08/2016 02:31 PM
It looks like I might be in Florida during this launch, so I'm also very curious about what a far-downrange recovery attempt will look like from a viewing point at the cape.


Daytime - you won't see anything.

Nightime - you should be able to see two out of three reentry burns.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/08/2016 02:45 PM
SES-8 launched at 5:41pm, a similar launch time for SES-9 would blur the line between "daytime" and "nighttime".  Sunset in Cape Canaveral on Feb 24 is 6:19pm; I think first stage flight is around 8 minutes, with another ~15 minutes for reentry/landing?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 03:37 PM
Seems like there are two options: #1 (most likely) it's going to be an expendable flight.  #2 (possible) they will attempt a two-burn profile... completely eliminating the boost-back burn, and instead just conducting the supersonic re-entry burn... and the landing burn.

Eliminating the boost-back burn would allow around 10s more of full-thrust flight, with the rocket very light at that point due to mostly depleted 1st stage tank.  No idea how much dV that would account for at that point in the flight.

My gut feeling is that they're just going to splash the stage, but we will see.


So its possible no she won't show us her legs? :)

I do believe (backed by a little calculation) that flying without legs and counting on going down to less than 5% fuel instead of 15% in the core at MECO-1 means that the 2nd stage starts with between 600 and 1000 m/s extra ΔV and given that the 2nd stage starts with a little more, it will add to what it can impart marginally (slightly less gravity loss so maybe 100m/s there).

EDIT (added stuff in italics)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FireJack on 02/08/2016 04:45 PM
Nowhere does it say that this means an expendable launch. IMO this means changes in how the second stage part plays out.
 
According to the wiki page the 1.1 falcon could put 4850kg into orbit, which makes me wonder about people saying the satellite 5,500kg. Did they decide the original was more capable that what is originally said?. Anyway with a 30% increase this would bring it up to 6300kg max, which still gives it some breathing room. If 5,500kg was the originals upper limit then the FT version should be capable of at least 7000kg to GTO.

Am I missing something or was the SES-9 always supposed to be launched on a FT?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/08/2016 04:54 PM
Yes, since Feb 2015 at least: http://spacenews.com/ses-decides-to-take-the-plunge-on-enhanced-falcon-9/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/08/2016 05:05 PM
Quote
with a 30% increase this would bring it up to 6300kg max, which still gives it some breathing room. If 5,500kg was the originals upper limit then the FT version should be capable of at least 7000kg to GTO.

SpaceX has never said explicitly whether it's 30% more to LEO or to GTO. Opinions here have varied as to which is correct.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mvpel on 02/08/2016 05:07 PM
It looks like I might be in Florida during this launch, so I'm also very curious about what a far-downrange recovery attempt will look like from a viewing point at the cape.
I will to, so SHHH! Don't jinx it!!
 ;D
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 02/08/2016 05:08 PM
I know pretty much nothing about transfer orbits, but given the satellite is using chemical propulsion to reach GEO and then electric to reach its operating position, would they be adjusting the transfer orbit to affect where the satellite actually enters GEO more than just trying to save delta-V on plane changes and orbit raising?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 05:17 PM
The spacecrafts bi-propellant motor was obviously not planned to do ALL the maneuvering to the final orbit:

Quote
SES-9 will use a chemical bi propellant apogee motor to quickly achieve a 24h synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity at 36,000 kilometers over the equator. Subsequent on-orbit manoeuvres will be executed with electric propulsion. - See more at: http://www.ses.com/4233325/news/2015/21833272#sthash.ANYiWaGO.dpuf

See http://www.ses.com/4233325/news/2015/21833272 (http://www.ses.com/4233325/news/2015/21833272)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/08/2016 05:41 PM
Musk has inferred that downrange recovery at Mach 9 is in the cards. Suggest that with mods Mach 11 is possible.

Suggest for the delta-V advantage gained in staging higher/faster, and with possibly tweaking US performance due to lower gravity losses, could make GTO-1800 AND further downrange landing.

Perhaps two burns - before EI and final braking. Enough to survive? Will they "go for it"?

Might require time for those mods, in addition to proving leg locks that don't have issues as before. How else would you prove them? Also, you might know just what to do, based on results from the last two flights.

And if he does try it, listen for if they say the staging height and velocity - those tell you a lot about the boundaries of F9R economics.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 05:45 PM
From the general Falcon and Dragon thread

So they could achieve a super synchronous orbit with an extended 1 stage burn, would they need to change the number of burns for the 2nd stage?

I don't know what they can add by just squeezing margins and trying a recovery still, but I am sure (see http://forum.nasaspaceflight.com/index.php?topic=34077.msg1489228#msg1489228][ur]http://forum.nasaspaceflight.com/index.php?topic=34077.msg1489228#msg1489228 (http://[ur)) they can add somewhere around 800m/s by giving up on recovery. So the extra 800m/s would add 300 or 400 more than needed to go from a sub syncronous at 25,000km Apogee to a super synch at 80,000. If there was extra performance available they could during the apogee boost burn, that starts at the ascending or descending node of the existing orbit as relates to an equatorial target orbit, shave off >2° of inclination difference for 300m/s. All in all it might be enough for the spacecraft's bi-prop engine to do everything except lowering the final apogee, far less energy than needed to raise the perigee.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/08/2016 05:51 PM
Seems like there are two options: #1 (most likely) it's going to be an expendable flight.  #2 (possible) they will attempt a two-burn profile... completely eliminating the boost-back burn, and instead just conducting the supersonic re-entry burn... and the landing burn.

Eliminating the boost-back burn would allow around 10s more of full-thrust flight, with the rocket very light at that point due to mostly depleted 1st stage tank.  No idea how much dV that would account for at that point in the flight.

My gut feeling is that they're just going to splash the stage, but we will see.

Additional option could be something like #3 testing to see if they have their lower limit for entry burns modeled correctly.  Basically, try to see if they can survive and control the stage while using the absolute smallest burn.  If it fails, then they've gathered more data for better modelling of edge cases.  If it succeeds, bonus landing attempt.

But generally I'm with you in that my gut thinking is that they'll just go full expendable.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/08/2016 06:18 PM
they can add somewhere around 800m/s by giving up on recovery.

So original plan asked for SES-9 chemical motor to achieve 24 hour synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity. Should we assume that with modified plan, SES-9 will use chemical motor to circularise and at least partially remove eccentricity? Wonder how much delta-V does chemical motor provide.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/08/2016 06:43 PM
Although I know next to nothing about orbital mechanics my gut feeling from having watched elon musk is that he will not miss an opportunity to obtain more data and will not be conservative. So I agree with others that a zero boostback 'landing' attempt either to water or barge with or without legs, however extreme, seems more likely than no attempt.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 07:01 PM
they can add somewhere around 800m/s by giving up on recovery.

So original plan asked for SES-9 chemical motor to achieve 24 hour synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity. Should we assume that with modified plan, SES-9 will use chemical motor to circularise and at least partially remove eccentricity? Wonder how much delta-V does chemical motor provide.

OK using the rocket equation and the following assumptions I get:

Dry weight 3000 (that was the dry weight of one BSS-702HP Boeing bus craft that was a hybrid electric using the same electric thrusters) - 312 ISP (R-4D engine like some BSS-702HP`s have used ) - and full weight of  5300 I get 1,741 m/s

if we increase the dry weight to 3500 it would be down to 1,270 m/s   I think for a number of reasons that the actual dry weight is somewhere within the range 3000 to 3500kg.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/08/2016 08:17 PM
Quote
SES-9 will use a chemical bi propellant apogee motor to quickly achieve a 24h synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity at 36,000 kilometers over the equator. Subsequent on-orbit manoeuvres will be executed with electric propulsion. - See more at: http://www.ses.com/4233325/news/2015/21833272
Parsing the tea leaves here, this implies a super-synchronous insertion.

First, I assume they meant inclination and not eccentricity.  (circularizing the orbit is the same as removing eccentricity, so no need to mention both, plus inclination reduction is the normally one of the final steps into GEO).

Now assume they will use as much delta-V as possible from chemical, then finish up with electrical.  If the GTO orbit is sub-synchronous, the the optimum transfer is (a) raise apogee to GEO by firing at perigee (chemical).  (b) fire at apogee to raise perigee as much as possible with chemical, (c) finish with electrical.  However, all of the intermediate states have <24 hour orbits. (Super-synchronous is not worthwhile here - it needs more delta-V total for reasonable apogees.  It's normally used because it shifts the delta-V needs to the second stage from the satellite, not since it takes less delta-V total.)

How about apogee at GTO?  Again, all the intermediate orbits are  <24 hour periods.

But super-synchronous fits the description.  Normally the next step is to fire at apogee to bring perigee up to GEO, resulting in an orbit with >24 hour period.  But if you don't have quite enough delta-V, you might be able to get to a 24 hour orbit with apogee above GEO and perigee below.  The you circularize and reduce inclination simultaneously with electric propulsion.

So within the limits of parsing technical details from PR material, this strongly suggests super-synchronous insertion.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 02/08/2016 08:21 PM
If it's super-synchronous (more than GTO-1800), it's almost definitely an expendable mission also. This satellite is too heavy for a DPL mission profile.


..if it isn't, then FT will be even more a beast than we thought it was. I would love to see this happen, but I don't think it will.
 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 08:48 PM


First, I assume they meant inclination and not eccentricity.  (circularizing the orbit is the same as removing eccentricity, so no need to mention both, plus inclination reduction is the normally one of the final steps into GEO).

It is not the final step if you are in an eccentric orbit where the apogee is at the ascending or descending node between the spacecraft orbit and the target orbit. You want to do the inclination change at the apogee then as it takes far less energy when the craft is already moving at the slowest speed relative to the Earth. So on a super synch orbit you change inclination at the apogee and settle into the plane before raising the perigee significantly or dropping the apogee.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/08/2016 09:04 PM


First, I assume they meant inclination and not eccentricity.  (circularizing the orbit is the same as removing eccentricity, so no need to mention both, plus inclination reduction is the normally one of the final steps into GEO).

It is not the final step if you are in an eccentric orbit where the apogee is at the ascending or descending node between the spacecraft orbit and the target orbit. You want to do the inclination change at the apogee then as it takes far less energy when the craft is already moving at the slowest speed relative to the Earth. So on a super synch orbit you change inclination at the apogee and settle into the plane before raising the perigee significantly or dropping the apogee.
I don't think this is correct.  Since the perigee/apogee modification and inclination reduction are at right angles, it always pays to do both simultaneously with each burn.  For example, if you need 1 m/s circularization and 1 m/s of inclination reduction, if you do these two separately you need 2 m/s.  But if you combine them you need only sqrt(2) m/s in a diagonal direction, by vector addition of velocities.  So the cheapest sequence is (a) inject into super GTO, removing some inclination as you do so.  (b) fire at apogee, raising the perigee and removing most of the rest of the inclination, (c) fire at perigee, circularizing the orbit and removing the last bit of inclination.

This is for impulsive burns.  I think the same will hold true for continuous small-thrust propulsion, since the triangle inequality will still apply (the vector sum of two burns is always < the sum of  the two burn's magnitudes, if they are not colinear).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 09:11 PM


First, I assume they meant inclination and not eccentricity.  (circularizing the orbit is the same as removing eccentricity, so no need to mention both, plus inclination reduction is the normally one of the final steps into GEO).

It is not the final step if you are in an eccentric orbit where the apogee is at the ascending or descending node between the spacecraft orbit and the target orbit. You want to do the inclination change at the apogee then as it takes far less energy when the craft is already moving at the slowest speed relative to the Earth. So on a super synch orbit you change inclination at the apogee and settle into the plane before raising the perigee significantly or dropping the apogee.
I don't think this is correct.  Since the perigee/apogee modification and inclination reduction are at right angles, it always pays to do both simultaneously with each burn.  For example, if you need 1 m/s circularization and 1 m/s of inclination reduction, if you do these two separately you need 2 m/s.  But if you combine them you need only sqrt(2) m/s in a diagonal direction, by vector addition of velocities.  So the cheapest sequence is (a) inject into super GTO, removing some inclination as you do so.  (b) fire at apogee, raising the perigee and removing most of the rest of the inclination, (c) fire at perigee, circularizing the orbit and removing the last bit of inclination.

This is for impulsive burns.  I think the same will hold true for continuous small-thrust propulsion, since the triangle inequality will still apply (the vector sum of two burns is always < the sum of  the two burn's magnitudes, if they are not colinear).

I certainly agree that you might as well raise the perigee at the same time for the reasons you point out, however it is more efficient at the start of the process, because as you raise the perigee you are are also increasing the amount of impulse needed for each degree of inclination change (which is a function of the speed of the craft at the point where you are applying the vector to change inclination and that speed increases as you increase the perigee).  However, my point was that the change of inclination is done from apogee of a super synch orbit before you bring that apogee down.

EDIT: Lou also when I was suggesting that if they were expending S1 that they should use some of the extra impulse available in the 2nd stage to eliminate some of the inclination, it was rather than throwing that extra impulse away, or raising the Apogee beyond 100,000km
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/08/2016 09:17 PM
However, my point was that the change of inclination is done from apogee of a super synch orbit before you bring that apogee down.


Which is the whole point of doing super synch.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: DanseMacabre on 02/08/2016 09:22 PM
Launch announcement for Feb. 24 according to this article.

https://uk.finance.yahoo.com/news/ses-9-launch-targeting-february-080000051.html

To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt. Good move.

I followed up with James Dean of FL today to confirm his note in his article that a landing would still be attempted; He needs to follow up and confirm no change to recovery ops. Link to thread here: https://twitter.com/flatoday_jdean/status/696682913425973248

James has confirmed ASDS landing: https://twitter.com/flatoday_jdean/status/696816102010200065

Looks like the rocket/bottle bank's still open for deposit ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/08/2016 09:28 PM
James has confirmed ASDS landing: https://twitter.com/flatoday_jdean/status/696816102010200065

Incredible. Thanks.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/08/2016 09:33 PM
If there was no incl change doesn't super sync still mean less delta-v to circularize?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 02/08/2016 09:34 PM


James has confirmed ASDS landing: https://twitter.com/flatoday_jdean/status/696816102010200065 (https://twitter.com/flatoday_jdean/status/696816102010200065)

Looks like the rocket/bottle bank's still open for deposit ;)

Wait, a super-synchronous insertion with a 5,300kg payload AND a stage 1 return?

O_o

This means more than 30% better GTO performance for the FT over v1.1 . It's a beast! (or some part of the information we have about the mission is incorrect).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Wonger on 02/08/2016 09:35 PM
James has confirmed ASDS landing: https://twitter.com/flatoday_jdean/status/696816102010200065 (https://twitter.com/flatoday_jdean/status/696816102010200065)

Incredible. Thanks.


IIRC SES wanted the opportunity to reuse the SES-9 S1, assuming all went well.  It makes sense that their modified launch profile would not preclude an ASDS landing attempt.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: eriblo on 02/08/2016 09:49 PM


James has confirmed ASDS landing: https://twitter.com/flatoday_jdean/status/696816102010200065 (https://twitter.com/flatoday_jdean/status/696816102010200065)

Looks like the rocket/bottle bank's still open for deposit ;)

Wait, a super-synchronous insertion with a 5,300kg payload AND a stage 1 return?

O_o

This means more than 30% better GTO performance for the FT over v1.1 . It's a beast! (or some part of the information we have about the mission is incorrect).
Did anyone actually confirm that this was not subsyncronous on FT? Otherwise it might still be, just less so...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 09:52 PM
If there was no incl change doesn't super sync still mean less delta-v to circularize?

No, if you had a craft in an 0° inclination equatorial LEO then putting it into an elliptical orbit with an apogee equal to the perigee and apogee of the target circular GEO orbit it would require less impulse to in a single impulse at apogee to circularize the orbit than the sum of the two impulses needed to raise the perigee then lower the apogee. Though each of those impulses individually would be lower than the single impulse needed to circularize the orbit in the direct case.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/08/2016 10:00 PM
If there was no incl change doesn't super sync still mean less delta-v to circularize?

No, if you had a craft in an 0° inclination equatorial LEO then putting it into an elliptical orbit with an apogee equal to the perigee and apogee of the target circular GEO orbit it would require less impulse to in a single impulse at apogee to circularize the orbit than the sum of the two impulses needed to raise the perigee then lower the apogee. Though each of those impulses individually would be lower than the single impulse needed to circularize the orbit in the direct case.
So the only advantage of super sync is to do the plane change at the lowest possible velocity.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 10:04 PM
If there was no incl change doesn't super sync still mean less delta-v to circularize?

No, if you had a craft in an 0° inclination equatorial LEO then putting it into an elliptical orbit with an apogee equal to the perigee and apogee of the target circular GEO orbit it would require less impulse to in a single impulse at apogee to circularize the orbit than the sum of the two impulses needed to raise the perigee then lower the apogee. Though each of those impulses individually would be lower than the single impulse needed to circularize the orbit in the direct case.
So the only advantage of super sync is to do the plane change at the lowest possible velocity.
Yes and I have never sat down and calculated it, but along with the axiom that the greater the plane change the greater the savings, there is also a minimum plane change below which it wasn't advantageous to increase the apogee for, that in fact it would have cost you more ΔV to go supersynch and correct back down than you saved in the plane change. However obviously since they have been doing super synch plane changes, there is an advantage when the plane changes is 26° or more.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Dante80 on 02/08/2016 10:14 PM

Did anyone actually confirm that this was not subsyncronous on FT? Otherwise it might still be, just less so...

The actual mission profile has not been announced. We can speculate though, from this:

Quote
In order to minimise the impact of moving the launch from late last year, SpaceX is supporting a mission modification. The changed mission will reduce the time needed for SES-9 to reach its orbital slot, keeping the Operational Service Date (OSD) in the third quarter of 2016, as previously foreseen.

The only possible way to offset the delay is to have a super-synchronous insertion. A more energetic sub-synchronous would definitely not suffice for explaining this announcement.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/08/2016 10:16 PM
If there was no incl change doesn't super sync still mean less delta-v to circularize?

No, if you had a craft in an 0° inclination equatorial LEO then putting it into an elliptical orbit with an apogee equal to the perigee and apogee of the target circular GEO orbit it would require less impulse to in a single impulse at apogee to circularize the orbit than the sum of the two impulses needed to raise the perigee then lower the apogee. Though each of those impulses individually would be lower than the single impulse needed to circularize the orbit in the direct case.

So would a "synchronous transfer orbit" (not sub, not super) still have an apogee beyond the GEO altitude? Put another way, the "simple Hohmann transfer" strategy where the apogee matches GEO altitude and all you need to do is raise perigee, that's subsynchronous, right?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 10:22 PM


So would a "synchronous transfer orbit" (not sub, not super) still have an apogee beyond the GEO altitude? Put another way, the "simple Hohmann transfer" strategy where the apogee matches GEO altitude and all you need to do is raise perigee, that's subsynchronous, right?

No, the simple Hohmann transfer orbit which is initiated at the point where the initial orbit crosses the equator and has an apogee equal to the altitude of a geosynchronous orbit is neither sub nor super synchronous.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/08/2016 10:26 PM


So would a "synchronous transfer orbit" (not sub, not super) still have an apogee beyond the GEO altitude? Put another way, the "simple Hohmann transfer" strategy where the apogee matches GEO altitude and all you need to do is raise perigee, that's subsynchronous, right?

No, the simple Hohmann transfer orbit which is initiated at the point where the initial orbit crosses the equator and has an apogee equal to the altitude of a geosynchronous orbit is neither sub nor super synchronous.

Ok, maybe I'm misunderstanding some simple orbit stuff (realize this is probably getting off topic pretty fast). But isn't period proportional to semi-major-axis^(3/2)? Semi-major axis of GEO is the radius. An elliptical orbit with the same apogee but lower perigee would have a smaller semi-major axis and therefore a shorter period?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/08/2016 10:29 PM


So would a "synchronous transfer orbit" (not sub, not super) still have an apogee beyond the GEO altitude? Put another way, the "simple Hohmann transfer" strategy where the apogee matches GEO altitude and all you need to do is raise perigee, that's subsynchronous, right?

No, the simple Hohmann transfer orbit which is initiated at the point where the initial orbit crosses the equator and has an apogee equal to the altitude of a geosynchronous orbit is neither sub nor super synchronous.

Ok, maybe I'm misunderstanding some simple orbit stuff (realize this is probably getting off topic pretty fast). But isn't period proportional to semi-major-axis^(3/2)? Semi-major axis of GEO is the radius. An elliptical orbit with the same apogee but lower perigee would have a smaller semi-major axis and therefore a shorter period?

Yes but when we speak of a geosynchronous transfer orbit, it is like speaking about a Mars transfer orbit, we aren't saying that the transfer orbit is synchronous, just that it is meant to take the craft to where it can maneuver into one. When we say sub synchronous we mean that it still isn't as high at apogee as the final orbit, and super means higher apogee than the final orbit. It is not referring to the period of the transfer orbit.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/09/2016 01:28 AM
However, my point was that the change of inclination is done from apogee of a super synch orbit before you bring that apogee down.
To first order this is right, but it's still not the minimum delta-V strategy.  It's (slightly) better to remove some inclination with each burn.  So at apogee you remove most (but not all) of the inclination.  Then your final apogee-decrease burn removes the remaining inclination.  This works because you can always get a minor amount of sideways thrust for very cheap.  For example, generating 1% of your delta-V in a perpendicular direction only reduces your main thrust to 99.995% of the original values.  (In general, adding  a small fraction x of sideways thrust costs only (1-x^2/2) of main thrust).   

Here's a post where user BowShock pointed this out to me.  http://forum.nasaspaceflight.com/index.php?topic=36954.msg1342012#msg1342012 .   Leaving 1.55 degrees of inclination to be removed by the last burn saves 8 m/s over removing all inclination at apogee 80000 km.  Not a huge deal , but this could be a few months of operation for a satellite, which typically uses 50 m/s per year of station keeping.
Quote
EDIT: Lou also when I was suggesting that if they were expending S1 that they should use some of the extra impulse available in the 2nd stage to eliminate some of the inclination, it was rather than throwing that extra impulse away, or raising the Apogee beyond 100,000km
This I completely agree with.  As you add available delta-V, go from sub-synchronous to synchronous to super-synchronous.  Then at some point even higher apogees save very little, but cause significant complications, so better to use any remaining delta-V to reduce the inclination of the transfer orbit.  In theory you can embrace super-high apogees, and do tricks like using the moon to reduce your inclination.  But this adds a lot of complications - you now have timing constraints on launch, your satellite may have problems such as Earth sensors that cannot cope, etc.  Probably best to just reduce the inclination as you suggest.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FireJack on 02/09/2016 01:46 AM
The big part of this launch is that a successful returned first stage will be reused.  This will hopefully let us know the economics of reusing rockets something both the ESA and Russians have said would not work.  How quickly can the first stage be turned around and at what price? How much new business will be created with these new prices? What will the reaction be from other launch providers?
Very exciting stuff.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: topo334 on 02/09/2016 02:30 AM
Do you mean the SES9 launch uses a previously flown first stage? (no), or that the first stage if landed, will be re-flown? Inquiring minds etc.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 02/09/2016 02:43 AM
To make up for the delay the satellite will be delivered to a better orbit for faster arrival at GEO. Which probably means no landing attempt.

The cynic in me is wondering whether the F9FT performance is less than expected, precluding the original nominal mission *and* barge landing so SpaceX just went ahead and committed all of the recovery reserve to SES-9.

Less than expected by whom? The original nominal mission was a sub-synchronous expendable insertion with v1.1. One month after that, it changed to a sub-synchronous DPL insertion with FT. FT has never been advertised to send a 5,300kg sat to GTO-1800 and then do a DPL. They actually list far less on their website (assuming the max they do list is for a DPL profile).

My take on this is that SES and SpaceX decided to go for a super-synchronous expendable mission profile so as to have the satellite come online sooner than expected, thus offsetting the delays that have plagued this campaign.

It's a good decision for business imo, although less exciting for SpaceX fans (that want to see the company nail its first FT barge landing sooner rather than later).

Certainly less exciting, but a single mission that puts a 5.3 ton bird in super sync orbit will make a big splash in the launch market.
From an objective perspective, this would be just as exciting as a valid ASDS landing. I look forward to a 7 ton launch to a sub sync GTO mission (for a purely electric bird).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 02:52 AM
Do you mean the SES9 launch uses a previously flown first stage? (no), or that the first stage if landed, will be re-flown? Inquiring minds etc.
There's only one previously flown first stage available at this time. I think it's pretty unlikely that it would be reused. SES has given no indication of interest in doing that. So I'm pretty sure he meant that if the first stage was recovered, it might be the first stage reflown. But that's my guess.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Wonger on 02/09/2016 03:25 AM
Do you mean the SES9 launch uses a previously flown first stage? (no), or that the first stage if landed, will be re-flown? Inquiring minds etc.


Some months back, SES asked SpaceX if the first stage from SES-9 was recovered, if they could use it again on a subsequent launch for a discount.  I don't think we ever heard SpaceX's response.  Article here:


http://spacenews.com/spacex-early-adopter-ses-ready-to-reuse-falcon-9-%C2%AD-for-the-right-price/ (http://spacenews.com/spacex-early-adopter-ses-ready-to-reuse-falcon-9-%C2%AD-for-the-right-price/)

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FireJack on 02/09/2016 03:29 AM
Yes I meant if the stage is recovered (which I think has a pretty good chance) it will likely be the first to be reused.
This will open the whole reused rocket market, which will be very interesting.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 02/09/2016 04:43 AM
Perhaps an option would be for the second stage to do a three burn profile; orbit insertion, transfer orbit (burn at low altitude at equator) and then geosynchronous transfer orbit (burn at apogee). This requires the second stage to stay alive for several hours after insertion.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/09/2016 05:21 AM
Given that it appears they are still going for the landing, it seems like one of the only things they could do (?) is eliminate the boost back burn, or most of it, and put that extra delta-v into the satellite. Any ideas how much that is? Not enough to get super synchronous, but closer? (hence reducing time to operation for the satellite). This has basically already been mentioned I think... but what else is there if they still try landing?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: 411rocket on 02/09/2016 06:32 AM
Yes I meant if the stage is recovered (which I think has a pretty good chance) it will likely be the first to be reused.
This will open the whole reused rocket market, which will be very interesting.

The previous plans that we know about, one landed stage will be re flown many times, at Space Port America, possibly until destruction. Another was to be thoroughly examined, maybe even dismantled, in the process of the exams & testing of components post-flight.

These were the plans, prior to Decembers Orbcomm flight & landing. So what has changed in the plans, aside from keeping that Booster, I think it is wait & see what happens....
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Star One on 02/09/2016 06:40 AM

The big part of this launch is that a successful returned first stage will be reused.  This will hopefully let us know the economics of reusing rockets something both the ESA and Russians have said would not work.  How quickly can the first stage be turned around and at what price? How much new business will be created with these new prices? What will the reaction be from other launch providers?
Very exciting stuff.

No the big part of this launch is delivering the customer's payload where & when they require it. Don't do that & quickly you will find that you have no business to do the rest.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ben the Space Brit on 02/09/2016 10:01 AM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?

2) So, SES want to reuse this core (F9-024, IIRC)? I wonder if, after SES-10 (if all goes to plan) they'll want to buy it off of SpaceX to be the Gate Guardian at their corporate HQ?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hkultala on 02/09/2016 11:49 AM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?

No.

What I've heard, they are making some tweaks based on the information received from the recovery and static fire of the reused second stage, propably to improve reliability.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jet Black on 02/09/2016 12:00 PM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?

No.

What I've heard, they are making some tweaks based on the information received from the recovery and static fire of the reused second stage, propably to improve reliability.

the second stage isn't reused.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: vandersons on 02/09/2016 12:22 PM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?


From what I read in the comments section on artechnica about the SES-9 launch the issue that is causing this delay was with a part of the fuel tank that came loose during the static fire of the used Orbcom stage. That part got ingested into one of the engines causing the thrust fluctuations. So now they're going through all of the already made stages and making that part more durable.
How accurate this information is I don't know as it was just a comment on an article. Seems reasonably plausible to me though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Paul_G on 02/09/2016 12:23 PM
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Brian45 on 02/09/2016 12:33 PM
As a "civilian" who understands a small amount of the discussion here and mainly lurks, I gather that because of the orbit intended and the weight of the satellite, the 1st stage won't have enough fuel to get itself back to it's launch location, instead they might attempt to land on the barge. Even that sounds iffy. It seems to me that if one tracks where the barge is, that would answer the question of Spacex's intentions.
Does anyone know what the plans are for the barge? When it is scheduled to leave port? What it's range is? If it leaves port earlier than in the past, would that mean it could be very far downrange, limiting the need to reverse direction (and burn fuel in doing so)?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: DanseMacabre on 02/09/2016 12:35 PM
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …

Information buried within the article:

Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.

// Aside - SpaceNews - Can you absolutely NOT hijack copypaste by adding stuff to the end, Sincerely - The Internet >:( .
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/09/2016 01:15 PM
As a "civilian" who understands a small amount of the discussion here and mainly lurks, I gather that because of the orbit intended and the weight of the satellite, the 1st stage won't have enough fuel to get itself back to it's launch location, instead they might attempt to land on the barge. Even that sounds iffy. It seems to me that if one tracks where the barge is, that would answer the question of Spacex's intentions.
Does anyone know what the plans are for the barge? When it is scheduled to leave port? What it's range is? If it leaves port earlier than in the past, would that mean it could be very far downrange, limiting the need to reverse direction (and burn fuel in doing so)?
Yes, we have eyes on the barge.  Check the ASDS thread here.  It hasn't moved yet.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 02/09/2016 01:23 PM
Confirmed by SES that the SES-9 launch will skip first stage recovery.

http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: IntoTheVoid on 02/09/2016 01:28 PM
Confirmed by SES that the SES-9 launch will skip first stage recovery.

http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

They are risking recovery, not abandoning. From the same article...
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jarnis on 02/09/2016 01:53 PM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?


From what I read in the comments section on artechnica about the SES-9 launch the issue that is causing this delay was with a part of the fuel tank that came loose during the static fire of the used Orbcom stage. That part got ingested into one of the engines causing the thrust fluctuations. So now they're going through all of the already made stages and making that part more durable.
How accurate this information is I don't know as it was just a comment on an article. Seems reasonably plausible to me though.

Merlin-1D needs to be damn robust if it can eat any kind of FOD like that and just have "fluctuations". That makes me suspect the comment a bit, but I guess it is theoretically possible.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Rebel44 on 02/09/2016 01:56 PM
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …

Information buried within the article:

Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.

// Aside - SpaceNews - Can you absolutely NOT hijack copypaste by adding stuff to the end, Sincerely - The Internet >:( .

That to me looks like high speed reentry, with recovery attempt using minimal viable amount of fuel.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 02:00 PM
As a "civilian" who understands a small amount of the discussion here and mainly lurks, I gather that because of the orbit intended and the weight of the satellite, the 1st stage won't have enough fuel to get itself back to it's launch location, instead they might attempt to land on the barge. Even that sounds iffy. It seems to me that if one tracks where the barge is, that would answer the question of Spacex's intentions.
Does anyone know what the plans are for the barge? When it is scheduled to leave port? What it's range is? If it leaves port earlier than in the past, would that mean it could be very far downrange, limiting the need to reverse direction (and burn fuel in doing so)?
My understanding was that the barge was already in plan, but with a "standard" burn profile... in this case, they will be trying to use the least fuel possible, meaning no retro burn at all? and the barge has to be as far down range as if it was a ballistic splash, or just about. That's my guesswork.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Fan Boi on 02/09/2016 02:05 PM
As a "civilian" who understands a small amount of the discussion here and mainly lurks, I gather that because of the orbit intended and the weight of the satellite, the 1st stage won't have enough fuel to get itself back to it's launch location, instead they might attempt to land on the barge. Even that sounds iffy. It seems to me that if one tracks where the barge is, that would answer the question of Spacex's intentions.
Does anyone know what the plans are for the barge? When it is scheduled to leave port? What it's range is? If it leaves port earlier than in the past, would that mean it could be very far downrange, limiting the need to reverse direction (and burn fuel in doing so)?
My understanding was that the barge was already in plan, but with a "standard" burn profile... in this case, they will be trying to use the least fuel possible, meaning no retro burn at all? and the barge has to be as far down range as if it was a ballistic splash, or just about. That's my guesswork.

I was wondering the same thing, a full ballistic trajectory with only aerodynamic braking and the landing burn. Grid fins and rocket body should slow it down some, will it be enough?

P.S. This does let us know she will keep her legs for this flight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/09/2016 02:16 PM
Sounds like a good test for the improved legs... :o
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/09/2016 02:25 PM
My understanding was that the barge was already in plan, but with a "standard" burn profile... in this case, they will be trying to use the least fuel possible, meaning no retro burn at all? and the barge has to be as far down range as if it was a ballistic splash, or just about. That's my guesswork.
This is my guess as well.  It would be very interesting to know SpaceX's take on this.  It could range from

"Our models indicate it's almost hopeless, but we'll see where it breaks" to

"We were going to try this anyway eventually - we'll just try it a little sooner" to

"Our only hope is to open the legs early and use them as air brakes. We don't even have a model for this since the aerodynamics are hideous, and it might be unstable and the legs might burn up from the exhaust, but we might as well give it a try..."

In any event, this is a good effect from testing after separation on existing flights, rather than dedicated tests.  You get to try things you might not try if you were paying for each test, since your worst case for testing (complete destruction) is exactly what would have happened anyway.  So you might as well try, and maybe learn something useful.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AndyX on 02/09/2016 03:14 PM
Chris's more fuller article was the first to reveal it was the second stage that caused the slip.
http://www.nasaspaceflight.com/2016/02/spacex-prepares-ses-9-mission-dragons-return/

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: GWH on 02/09/2016 03:15 PM
If they do manage to land this one I'm betting it won't fly again.  Simply for the fact that they will need to push it's reentry profile as close to or beyond the theoretical limit and a full tear down and analysis would tell them a massive amount in regards to their margins.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 03:18 PM
After the Asiasat 6 launch, Musk tweeted this

Quote
High velocity reentry (2700 lbs/sqft) appeared to succeed, but, as expected, not enough propellant to land for this and the next mission.

https://twitter.com/elonmusk/status/496673908129804288

So, even a modest amount of braking via the reentry burn might make it survivable. Of course, that flight didn't have grid fins that could be ripped off by high Q...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kdhilliard on 02/09/2016 03:20 PM
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …

Quote from: the article
“There are things [on the rocket] that have not been tested yet but the mere fact that they have eliminated [first stage] recovery will help,” Sabbagh said in an interview. “You can improve the time it takes to get to orbit. By how much will we reduce it? We don’t know, and we wont’ know until the day after the launch.”

What hasn't been tested?  Restart after long coast?

~Kirk
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 03:21 PM
I'm thinking he might have been talking about preflight processing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Star One on 02/09/2016 03:25 PM
This is an important quote from the above article to keep in mind.

Quote
For commercial fleet owners, stage recovery is a nice idea so long as it does not perturb the optimal placement into orbit of their satellites, many of which have cost more than $200 million.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: starsilk on 02/09/2016 03:32 PM
Two thoughts occur to me:

1) Is there any hint that the delay in the launch might be because SpaceX have been completing works on a performance tweak to the upper stage?


From what I read in the comments section on artechnica about the SES-9 launch the issue that is causing this delay was with a part of the fuel tank that came loose during the static fire of the used Orbcom stage. That part got ingested into one of the engines causing the thrust fluctuations. So now they're going through all of the already made stages and making that part more durable.
How accurate this information is I don't know as it was just a comment on an article. Seems reasonably plausible to me though.

Merlin-1D needs to be damn robust if it can eat any kind of FOD like that and just have "fluctuations". That makes me suspect the comment a bit, but I guess it is theoretically possible.

earlier Merlins were supposed to be designed to eat a #8 nut and survive, not sure if that still applies to 1D.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 03:38 PM
In any event, this is a good effect from testing after separation on existing flights, rather than dedicated tests.  You get to try things you might not try if you were paying for each test, since your worst case for testing (complete destruction) is exactly what would have happened anyway.  So you might as well try, and maybe learn something useful.
There is a potential downside, which is that you cause more damage to (something) than you would have if you just let the stage break up and no one was around...  I don't want to concern troll, but this could be a wild experience for our lovable little ASDS. But ASDSs have survived several sporty landing attempts so far...

But ya I almost completely agree with you, this is a no brainer. Try every time. Learn every time. Expand the envelope.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/09/2016 03:53 PM
My understanding was that the barge was already in plan, but with a "standard" burn profile... in this case, they will be trying to use the least fuel possible, meaning no retro burn at all? and the barge has to be as far down range as if it was a ballistic splash, or just about. That's my guesswork.
IF (and that's a big IF) they can make this work (aerodynamic braking only, followed targeting with fins, then landing burn) then that would allow a pretty small penalty for booster recovery.

The landing burn takes only 30 sec or so, with one engine at partial thrust.  So this means 3 seconds less of uphill flight from the booster.  It's accelerating at a little less than 5 G at that point, so the velocity penalty is about 150 m/s.  Now currently, to get to GTO-1500, the second stage must supply something like 8500 m/s.  If instead it needs to supply 8650 m/s, the mass ratio changes from 12.09 to 12.63.  Assuming a second stage starting mass of 125 tonnes (per Musk statement) this change the burnout mass from 10339 kg to 9897 kg, for a loss in payload of 442 kg.  This is only 8.3% of a 5300 kg satellite.

The penalty would be even smaller for GTO-1800, and smaller yet for LEO.   Such small penalties for recovery means very few payloads would be in the gray zone where an expendable makes sense.  Of course this is IF they can get purely aerodynamic braking to work, and that's a huge if.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/09/2016 04:03 PM
So working backwards from the 2nd stage, the new FT 2nd stage is supposed to have 113t of prop and a dry weight of 6t (as per OldAtlasEguy's estimates) with a 5.3t payload it would have a ΔV of 8,183m/s and a max acceleration of 8.4g at full thrust (5.04g if it can throttle to 60%).  So using a 5% rule of thumb margin on its ΔV (leaves 7770m/s, for GTO we need the first stage to have delivered the 2nd stage to 7800m/s +2500 - 7770 = 2526m/s of horizontal velocity component and enough vertical component to reach orbital altitude, if we presume we need another 250 m/s to get to the super synch orbit and 100m/s for the last bit of gravity loss that the 2nd stage will experience going to orbit, then that is 2876m/s horizontal component at first stage MECO. At this point the first stage will be coasting upwards and then downwards for several minutes before it transitions into atmosphere thick enough to slow it down and the total velocity that it hits the air with will include the vector addition of the vertical component of the velocity which will definitely take the stage above 3000m/s air speed.

The last 1% of fuel in the F9 with legs is good enough to provide a ΔV of 400m/s probably just enough with gravity losses to make the landing from terminal velocity.

The last 5% of fuel in the F9 with legs would provide a ΔV of 1650m/s (1250 more than landing needs) that would mean a re-entry speed of at least 1750m/s after braking on a two burn re-entry mission plan.

The last 10% of fuel in the F9 with legs would provide a ΔV of 2650m/s  that would get the craft down to 750m/s from which point it would speed up again in a two burn profile, but probably not enough to have significant heating and also within the control range of the grid fins.

So if we presumed that original plan was for 11% fuel remaining at MECO and that they are going to give up 5% of that to try to recover with 6% remaining the performance difference at MECO would be 343m/s. That is definitely enough to go from sub to super synch and it would also add just marginally to the 2nd stage performance by reducing its gravity loss slightly.

I have no idea what the real mission profiles were, but this gives me an idea how much more difficult recovery would get by splitting the difference between a sure fire full downrange two burn recovery plan and a risky but maybe possible one.


Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/09/2016 04:27 PM
What if they split the difference between a two and one burn profile, and go with a one-engine supersonic burn at entry interface instead of a three, with a similar duration?  Although from your numbers it sounds like they could do a two-burn profile with a little margin to spare, so maybe that isn't required. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Hotblack Desiato on 02/09/2016 04:29 PM
F9 (all versions) have an extra capacity in case an engine fails (like in CRS-1). Does the first stage tap into this reserve (assuming all 9 engines work as planned)? Especially since that fuel reserve has to be available from the first second of the flight on.

Otherwise, it seems as if the first stage might have a chance to land on the barge, but the stage would come down running on fumes, at best (one good thing, empty stages just crash, they don't explode).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/09/2016 04:33 PM
What if they split the difference between a two and one burn profile, and go with a one-engine supersonic burn at entry interface instead of a three, with a similar duration?  Although from your numbers it sounds like they could do a two-burn profile with a little margin to spare, so maybe that isn't required.

Normal profile is 3 burns (the first is to either slow/stop or to RTLS on a high trajectory, the 2nd is the atmospheric retropulsion, the 3rd is the landing burn).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: francesco nicoli on 02/09/2016 04:35 PM
So working backwards from the 2nd stage, the new FT 2nd stage is supposed to have 113t of prop and a dry weight of 6t (as per OldAtlasEguy's estimates) with a 5.3t payload it would have a ΔV of 8,183m/s and a max acceleration of 8.4g at full thrust (5.04g if it can throttle to 60%).  So using a 5% rule of thumb margin on its ΔV (leaves 7770m/s, for GTO we need the first stage to have delivered the 2nd stage to 7800m/s +2500 - 7770 = 2526m/s of horizontal velocity component and enough vertical component to reach orbital altitude, if we presume we need another 250 m/s to get to the super synch orbit and 100m/s for the last bit of gravity loss that the 2nd stage will experience going to orbit, then that is 2876m/s horizontal component at first stage MECO. At this point the first stage will be coasting upwards and then downwards for several minutes before it transitions into atmosphere thick enough to slow it down and the total velocity that it hits the air with will include the vector addition of the vertical component of the velocity which will definitely take the stage above 3000m/s air speed.

The last 1% of fuel in the F9 with legs is good enough to provide a ΔV of 400m/s probably just enough with gravity losses to make the landing from terminal velocity.

The last 5% of fuel in the F9 with legs would provide a ΔV of 1650m/s (1250 more than landing needs) that would mean a re-entry speed of at least 1750m/s after braking on a two burn re-entry mission plan.

The last 10% of fuel in the F9 with legs would provide a ΔV of 2650m/s  that would get the craft down to 750m/s from which point it would speed up again in a two burn profile, but probably not enough to have significant heating and also within the control range of the grid fins.

So if we presumed that original plan was for 11% fuel remaining at MECO and that they are going to give up 5% of that to try to recover with 6% remaining the performance difference at MECO would be 343m/s. That is definitely enough to go from sub to super synch and it would also add just marginally to the 2nd stage performance by reducing its gravity loss slightly.

I have no idea what the real mission profiles were, but this gives me an idea how much more difficult recovery would get by splitting the difference between a sure fire full downrange two burn recovery plan and a risky but maybe possible one.

In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 02/09/2016 04:37 PM
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …

Information buried within the article:

Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.

// Aside - SpaceNews - Can you absolutely NOT hijack copypaste by adding stuff to the end, Sincerely - The Internet >:( .

That to me looks like high speed reentry, with recovery attempt using minimal viable amount of fuel.

"fail forward"...  Classic SpaceX.

And, btw, it's high-speed re-entry, not high-speed landing*.  Terminal velocity will be the same and the final burn will be the same.   They're just going to use a lot less, if any, "magic sauce" on reentry.

* unless of course they run out of fuel on the way down
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 04:41 PM
In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.

They could always say there will be no landing attempt this time, show no live ASDS footage and share no videos afterwards. Is that the path you wish them to take?

The fact they released the Jason-3 landing video (and previous ones) shows that their thinking about explosions is a bit different than yours.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Hotblack Desiato on 02/09/2016 04:50 PM
In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.

They could always say there will be no landing attempt this time, show no live ASDS footage and share no videos afterwards. Is that the path you wish them to take?

The fact they released the Jason-3 landing video (and previous ones) shows that their thinking about explosions is a bit different than yours.

Yes, it might be a PR-problem for them, but those who follow it closely will know that they said in advance that this is a very difficult landing with a high chance of failure. And the others already believe that SX stage recovery is a hoax, because it didn't work 3 times in a row.

Besides, so far every customer pays for a full expendable flight. Landing a stage for development is important for development, but not landing one isn't a monetary loss.

@nadrek: how much better is the calculation, if they leave the legs away? (yes, I know, no legs, no landing).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: John Alan on 02/09/2016 04:54 PM
Suggest NASA fly the RB-57 again and get some high altitude IR video of this 'worst case' attempt...

http://www.nasa.gov/missions/research/b-57_feature.html

May be worth it...  ;)

If they land it.. .Great...
If not... at least the video may help in understanding what went wrong...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/09/2016 04:58 PM
@Lar if the attempt fails, they are likely going to arrive nowhere near the ASDS.  Arriving close enough to damage the ASDS means that the landing attempt basically worked.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/09/2016 04:58 PM


@nadrek: how much better is the calculation, if they leave the legs away? (yes, I know, no legs, no landing).

Leaving the legs off only makes a difference of about 30m/s in the 5% case, but there is no point not burning to just about empty if you leave the legs off. The big difference with the legs is the boostback and retropulsion numbers since it makes a big difference to the total mass of the craft (more than 10% vs .5% of launch weight or 2% of full upper stage mass plus stage one empty weight). However there is no point doing retropulsion or boostback with no legs 8)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/09/2016 05:00 PM
In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.

One alternative is that they don't mention the recovery attempt, i.e. use the "The F9 for this flight will be in expendable mode", and then attempt the landing anyway, minus the hype and live coverage. Then if it fails no one the wiser (well, except all the enthusiasts that know where the barge is at every moment, and the support ships, and who would note the existence of legs and fins on the bird, etc... But from an official PR stance, it was an expendable mission).

And if it succeeds, then well, it's a win win and they can release some glorious footage...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: abaddon on 02/09/2016 05:02 PM
What if they split the difference between a two and one burn profile, and go with a one-engine supersonic burn at entry interface instead of a three, with a similar duration?  Although from your numbers it sounds like they could do a two-burn profile with a little margin to spare, so maybe that isn't required.

Normal profile is 3 burns (the first is to either slow/stop or to RTLS on a high trajectory, the 2nd is the atmospheric retropulsion, the 3rd is the landing burn).
Right.  I'm assuming that the first burn is out, the second burn is what I am talking about possibly using one engine for the same duration instead of three.  Maybe they don't need to do that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 05:07 PM
Disregard energy management for a moment. In addition to that basic function, the boostback/slowdown and reentry burns also serve as trajectory correction maneuvers. Without them, there is a possibility that the uncertainty in the state vector at 1st stage cutoff would be too big for just the fins to compensate for during reentry phase.

In short, I think there has to at least be a short reentry burn to aim toward the general area of the ASDS and then to rely on the fins for finer adjustments before landing burn.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/09/2016 05:11 PM

Right.  I'm assuming that the first burn is out, the second burn is what I am talking about possibly using one engine for the same duration instead of three.  Maybe they don't need to do that.

I don't know what the difference in how the retropulsion exhaust gases impact the way the air decelerates the rocket is, if any. But it doesn't make any difference to the amount of ΔV that is provided by different amounts of fuel left, just makes a difference how fast the rocket decelerates and what the gravity losses will be (though they will be minimal either way, in the one engine scenario they will be roughly 3 times the minimal in the three engine scenario).

and in other news:

Disregard energy management for a moment. In addition to that basic function, the boostback/slowdown and reentry burns also serve as trajectory correction maneuvers. Without them, there is a possibility that the uncertainty in the state vector at 1st stage cutoff would be too big for just the fins to compensate for during reentry phase.

In short, I think there has to at least be a short reentry burn to aim toward the general area of the ASDS and then to rely on the fins for finer adjustments before landing burn.

Besides the difference between re-entry heating at 3km/s and 1.5 is 4 times!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 05:15 PM
Besides the difference between re-entry heating at 3km/s and 1.5 is 4 times!

Like I posted earlier, there already is precedent for a stage surviving a 4x higher dynamic pressure, Asiasat 6. I say pressure, not heating because I believe dynamic pressure is the big issue, not heating on an engine section that carries hefty TPS anyway. Musk also quotes psf, not temperatures.

It doesn't prove all such entries would work and it doesn't prove F9FT with the grid fins and legs would fare as good and certainly actually guiding a stage toward a certain landing spot is more challenging. It's apparently not an outright death sentence for a stage, though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mme on 02/09/2016 05:31 PM
In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.

One alternative is that they don't mention the recovery attempt, i.e. use the "The F9 for this flight will be in expendable mode", and then attempt the landing anyway, ...

And if it succeeds, then well, it's a win win and they can release some glorious footage...

That's the Blue Origin way not the SpaceX way.  Musk and Shotwell both love to tell people that if you aren't failing at experiments, then you aren't pushing the boundaries enough.  No way does Musk stay silent about trying something crazy.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: whitelancer64 on 02/09/2016 05:42 PM
Disregard energy management for a moment. In addition to that basic function, the boostback/slowdown and reentry burns also serve as trajectory correction maneuvers. Without them, there is a possibility that the uncertainty in the state vector at 1st stage cutoff would be too big for just the fins to compensate for during reentry phase.

In short, I think there has to at least be a short reentry burn to aim toward the general area of the ASDS and then to rely on the fins for finer adjustments before landing burn.

The grid fins deploy while the 1st stage is still well above the Karman Line, so they should have good control all through the descent. The stage would be on an entirely ballistic trajectory prior to atmospheric reentry, so the trajectory uncertainty should be low. Whether or not the stage survives reentry without a deceleration burn is probably the bigger question.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 05:49 PM
The stage would be on an entirely ballistic trajectory prior to atmospheric reentry, so the trajectory uncertainty should be low.

Why should/would it be low? That ballistic trajectory will have basically been set up several minutes earlier when staging happened so any state vector difference at that point to what the preflight staging predict was would have quite a bit of time to propagate into a bigger downrange impact point uncertainty. Of course I have no actual numbers to back any of this up.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: whitelancer64 on 02/09/2016 06:00 PM
The stage would be on an entirely ballistic trajectory prior to atmospheric reentry, so the trajectory uncertainty should be low.

Why should/would it be low? That ballistic trajectory will have basically been set up several minutes earlier when staging happened so any state vector difference at that point to what the preflight staging predict was would have quite a bit of time to propagate into a bigger downrange impact point uncertainty. Of course I have no actual numbers to back any of this up.

Well, not to sound unhumble, but something that it turns out we've generally been pretty good at over the past ~50 years or so is calculating ballistic trajectories (See: Apollo, Voyager and misc. other probes, etc.). Where the uncertainty lies is the amount of drag that the rocket will encounter, since the atmosphere (especially at high altitudes) is so variable that that's difficult to pin down with precision.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/09/2016 06:01 PM
No, no, I'm not talking about us not being able to *propagate* a state vector. I'm talking about the uncertainty of the starting point, at staging. In your interplanetary example, think about injection errors.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/09/2016 06:18 PM
Disregard energy management for a moment. In addition to that basic function, the boostback/slowdown and reentry burns also serve as trajectory correction maneuvers. Without them, there is a possibility that the uncertainty in the state vector at 1st stage cutoff would be too big for just the fins to compensate for during reentry phase.

In short, I think there has to at least be a short reentry burn to aim toward the general area of the ASDS and then to rely on the fins for finer adjustments before landing burn.

The grid fins do provide a pretty good amount of aerodynamic steering.  It would have to be pretty far off ballistically to be too far away from the glide cross-range capability of the grid fins.

For this kind of flight/landing attempt, you would expect them to locate the ASDS right where a ballistic descent  of the booster would be projected to splash down.  But as you imply, there could be some variability in that at cutoff.  I do not know how many off-nominal miles downrange such an error might be, or how many miles glide cross-range the grid fins can provide (I know, it’s not a very good glide. But it starts being effective from a high altitude).

But let's say that the error is too far for the grid fins to handle  One possibility for that would be during turnaround, only pitch about 90 degrees to the proper vector attitude direction needed and then do a lateral (perpendicular to flight path) course correction burn to put the projected ballistic descent path  back inside the ballpark for the grid fins to be able to glide it in to home plate later.  Would not require much of  burn to do that kind of course correction, zero wasted on retro, 100% for nudging the descent path close enough to the barge for the grid fins to handle.  Of course any burn in this case uses fuel that should be saved as much as possible for landing. But there’s not much point soft-landing on water, been there, done that.

Anyway, I sort of agree that if the ballistic path is off nominal and  happened to be beyond what the grid fins can handle (which is a lot), that there might be a need for a “short burn”.  But not a re-entry burn. An incredibly brief  90 degree attitude course-correction burn as soon after staging as it can calculate for, maneuver,  and  do it.  Because the sooner it does it, the less delta-v required and thus less propellant.

All  the above of course presumes the vehicle withstands such a high-speed re-entry and still works properly, I'm only referring to grid fin glide range and a possible course correction option.

Would be a hell of a great thing if after 3 failures to land safely on an ASDS, this one made it despite lack of a boost-back burn (which even the ASDS landings have had to an extent) and lack of retro burn.

- George Gassaway
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: notsorandom on 02/09/2016 06:39 PM
Correct me if I'm wrong but cross range depends on not only the ability to control attitude but also the ability to generate lift to change the direction of the velocity vector. Pointing in a certain direction in of itself without lift does no good to change that vector. Are Falcon's fins big enough to generate enough lift or does it use the rocket's body to help do so? If that is the case there is likely a limit to how big the angle of attack can be before the rocket fails due to heating or becomes uncontrollable.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/09/2016 06:49 PM
The rocket's body generates lift.  The grid fins just maintain it at the proper angle-of-attack to do so.  Stall typically occurs between 15 and 20ish degrees.  The grid fins will likely keep it below stall to minimize the forces on the body.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 06:57 PM
@Lar if the attempt fails, they are likely going to arrive nowhere near the ASDS.  Arriving close enough to damage the ASDS means that the landing attempt basically worked.
The only scenario where that would *not* be the case is where it "almost worked" and the engine ran out early (or failed to start due to some damage from the additional heating it normally doesn't experience?)  but the grid fins did a great job of guidance so the stage smacked right into the ASDS dead center at a good clip...

But of course that is where the guidance computer is supposed to divert to miss... so that probably won't happen either.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/09/2016 06:59 PM
@Lar if the attempt fails, they are likely going to arrive nowhere near the ASDS.  Arriving close enough to damage the ASDS means that the landing attempt basically worked.
The only scenario where that would *not* be the case is where it "almost worked" and the engine ran out early (or failed to start due to some damage from the additional heating it normally doesn't experience?)  but the grid fins did a great job of guidance so the stage smacked right into the ASDS dead center at a good clip...
We've been over this again and again in the ASDS threads.  The barge so outmasses the rocket that not much would happen, collision-wise, even of you were to manage an impact at stage terminal velocity.  Think light aluminum soda can hitting massive steel wall.  The ASDS is also ballasted with water during landing, adding further to its mass.  It also has multiple sealed compartments, if you are worried about a Titanic situation.

Edit: and again, managing to hit the ASDS implies that the rocket is intact which implies that the atmosphere has already succeeded in slowing the stage down to terminal velocity.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/09/2016 07:18 PM
Okay yeah, but 20 tons of just about anything moving at hundreds of miles per hour would damage the barge significantly.

But that's what the barge is for and why it's steel and not fiberglass. Weld the hole shut when you get back to shore.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CraigLieb on 02/09/2016 07:20 PM
Okay yeah, but 20 tons of just about anything moving at hundreds of miles per hour would damage the barge significantly.

But that's what the barge is for and why it's steel and not fiberglass. Weld the hole shut when you get back to shore.
And the Video would be EPIC! but here's to hope we don't see one like that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 07:26 PM
Okay yeah, but 20 tons of just about anything moving at hundreds of miles per hour would damage the barge significantly.

But that's what the barge is for and why it's steel and not fiberglass. Weld the hole shut when you get back to shore.

I don't think it's a likely outcome anyway but where I could see it causing issues is debris from the impact hitting equipment, Not so much damaging the deck itself. And the equipment is now protected behind walls (IIRC).

A terminal velocity impact is different than a low speed impact. So the splash paths of debris might be different, and it may be more (or less) energetic. But I expect more.

Review the footage of straws driven through boards by tornadoes... aluminum cans might well damage containers (if not for the blast walls) despite being flimsy.

Anyway this is fun to talk about and I'm excited. I hope they go for it and will be rooting for them. Fail forward. If you're not falling you're not skiing hard enough...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 02/09/2016 07:45 PM
@ugordon: Do we have any evidence that on prior braking burns F9 used its current state as an input into the burn direction or duration? Is it possible all prior braking burns have been "open loop" i.e. with pre-determined directions and durations? Conceivably just doing a very brief but "navigated" burn might get them onto a ballistic trajectory with better accuracy on this attempt than on prior attempts....
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/09/2016 07:46 PM
Not to open a can of worms, but could they unzip the booster if it's determined to be more of an anti ASDS weapon rather then a lovely companion rocket, or can only the Range trigger the FTS (and if so, would they initiate it in order to spare excessive damage to the barge).

By the way - it could very easily do significant damage to the barge and systems. Look at the damage that the original JRTI sustained on the first landing attempt. I've attached an image just in case you forgot. Those are steel containers that house the diesel generators for the thrusters, among other things. Crumpled by that flimsy tin can. That kind of damage could really put a crimp in an aggressive launch (recovery) manifest.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/09/2016 07:52 PM
Quote
Not to open a can of worms, but could they unzip the booster if it's determined to be more of an anti ASDS weapon rather then a lovely companion rocket, or can only the Range trigger the FTS

Only Range can send a destruct command.

Quote
By the way - it could very easily do significant damage to the barge and systems. Look at the damage that the original JRTI sustained on the first landing attempt.

That's why they added blast walls.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Semmel on 02/09/2016 08:23 PM
Not to open a can of worms, but could they unzip the booster if it's determined to be more of an anti ASDS weapon rather then a lovely companion rocket, or can only the Range trigger the FTS (and if so, would they initiate it in order to spare excessive damage to the barge).

Also I think I heared "FTS is safed" on the radio in last missions prior to the landing attempt. I think its noted around the reentry burn. So no more FTS near the barge in any case.

@edit: thx mheney, I saved that change :P
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mheney on 02/09/2016 08:39 PM
Not to open a can of worms, but could they unzip the booster if it's determined to be more of an anti ASDS weapon rather then a lovely companion rocket, or can only the Range trigger the FTS (and if so, would they initiate it in order to spare excessive damage to the barge).

Also I think I heared "FTS is saved" on the radio in last missions prior to the lading attempt. I think its noted around the reentry burn. So no more FTS near the barge in any case.

"Safed", not saved. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Raj2014 on 02/09/2016 08:52 PM
Is SpaceX attempting another landing again? If yes, where will they land the Falcon?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Sam Ho on 02/09/2016 09:36 PM
Is SpaceX attempting another landing again? If yes, where will they land the Falcon?

Yes, please see from earlier today in this thread:
Peter B. de Seldin @pbdes

https://twitter.com/pbdes/status/697042594946273280

SES CEO: We applaud SpaceX willingness to put rocket recovery aside on behalf of SES-9 reconfigured launch.http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ …

Information buried within the article:

Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.

// Aside - SpaceNews - Can you absolutely NOT hijack copypaste by adding stuff to the end, Sincerely - The Internet >:( .
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/10/2016 03:15 AM
Correct me if I'm wrong but cross range depends on not only the ability to control attitude but also the ability to generate lift to change the direction of the velocity vector.
In the case of my message, I was referring ONLY to a possible course correction burn to alter the ballistic path enough for the grid fins to be able to steer it aerodynamically the rest of the way to be in the right position for the landing burn (if the ballistic path was too far away for grid-fin cross-range).

I never meant to imply that it would hold at 90 degrees after such a brief burn.

 Of course it would rotate tail-first after that, begin re-entry and grid fins do their thing as much as possible to hopefully get it there the rest of the way (assuming it survives such a fast re-entry to begin with and is still working properly).

OK, I just realized one possible problem with trying to do a brief course correction burn at 90 degrees to the flight path soon after staging.  Ullage.  Do not know if the RCS thrusters can provide positive ullage acceleration to get the propellants settled in to feed the engine(s) or not. Do not recall if there is enough thin air at the previous boostback burn start altitudes (shortly after staging) for there to be enough aerodynamic deceleration to act like ullage to settle the propellants or if the F9 core is doing it with RCS.

- George Gassaway
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 02/10/2016 03:35 AM
I will note that any F9 stage 1 recovery requires a minimum of two post-boost burns -- an entry burn and a landing burn.  The entry burn not only serves to reduce the speed of the incoming stage, it also, perhaps more importantly, creates a shield in the form of the engine exhaust, which protects the leading end of the stage (the octaweb) from suffering excessive frictional heating -- which will be on the high end of what F9 is designed to handle on a Mach 9 entry.

So, it will need to have an entry burn to survive entry, and then have enough left in the tanks for a landing burn.

The one bad day scenario that comes to mind is the one where the stage gets to the beginning of the landing burn and runs out of fuel within a few seconds of the beginning of that burn.  The navigation state could well be, at that point, such that the grid fins would be able to steer the stage onto a direct-center hit on the ASDS -- but without the engine running, hitting dead center at several hundred miles an hour.  And the nav system likely will try to hit the target, whether or not the engine is running.

That may or may not be enough to hole the barge badly enough to make her irreparable.  But without a wave-off capability in case of engine out, it might end up happening...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zed_Noir on 02/10/2016 05:01 AM
I will note that any F9 stage 1 recovery requires a minimum of two post-boost burns -- an entry burn and a landing burn.  The entry burn not only serves to reduce the speed of the incoming stage, it also, perhaps more importantly, creates a shield in the form of the engine exhaust, which protects the leading end of the stage (the octaweb) from suffering excessive frictional heating -- which will be on the high end of what F9 is designed to handle on a Mach 9 entry.

So, it will need to have an entry burn to survive entry, and then have enough left in the tanks for a landing burn.

The one bad day scenario that comes to mind is the one where the stage gets to the beginning of the landing burn and runs out of fuel within a few seconds of the beginning of that burn.  The navigation state could well be, at that point, such that the grid fins would be able to steer the stage onto a direct-center hit on the ASDS -- but without the engine running, hitting dead center at several hundred miles an hour.  And the nav system likely will try to hit the target, whether or not the engine is running.

That may or may not be enough to hole the barge badly enough to make her irreparable.  But without a wave-off capability in case of engine out, it might end up happening...

No big deal. If the prop state goes bingo. Use the grid fins & N2 thrusters to diverge from the ASDS and do a water slam. Presuming the software have this scenario covered along with prop level sensors in place.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 02/10/2016 05:20 AM
In terms of PR, is it worthy to try recovery of with very low chances of success? big ground explosions are no good for SpaceX reputations, they would be flown by "fourth barge attempt explosion in a row" headlines everywhere.
Humans yearn for significance, so we like to think that what the public thinks about SpaceX matters (including us).
The reality is the number one priority is gathering data and advancing all aspects of recovery. Number two priority is to impress current and prospect SpaceX customers. PR with the general public is a distant third.
If SpaceX can put a 5.3T bird to GEO-1500m/s and make the stage destroy the ASDS, it will positively impress customers. It might mean they can put a 5.1T bird to GET-1500m/s and land. And its more likely the stage will disintegrate through re-entry or miss by a fraction of a mile than be unable to land.
We need to realize that most orders for birds coming up for launch in 2016 were put before SpaceX was a serious GEO launch supplier.
What SpaceX is doing now will influence new orders for GEO birds.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/10/2016 06:48 AM
OK, I just realized one possible problem with trying to do a brief course correction burn at 90 degrees to the flight path soon after staging.  Ullage.  Do not know if the RCS thrusters can provide positive ullage acceleration to get the propellants settled in to feed the engine(s) or not. Do not recall if there is enough thin air at the previous boostback burn start altitudes (shortly after staging) for there to be enough aerodynamic deceleration to act like ullage to settle the propellants or if the F9 core is doing it with RCS.

- George Gassaway

What are you asking? Are you doubting that boost back burns take place shortly after staging?

The thrusters have always provided the ullage needed for the boost back ignition. The stage is at ~80km and rising rapidly at stage separation, so the atmosphere is not enough.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/10/2016 07:50 AM
What are you asking? Are you doubting that boost back burns take place shortly after staging?

The thrusters have always provided the ullage needed for the boost back ignition. The stage is at ~80km and rising rapidly at stage separation, so the atmosphere is not enough.

I am not doubting at all that boost back burns have been done for past  landings.

But it sounds like for the SES-9 landing attempt, in order to sacrifice a lot of landing fuel for the payload's mission, it's not going to do a  boostback burn, or a re-entry burn.  A very fast natural ballistic descent until the grid fins start to become effective. A  sort of Hail Mary that it can survive, with the grid fins aerodynamically steering it to the ASDS, with the only burn being for landing.

 My  comment about a possible brief course correction burn (at 90 degrees to the flight path) soon after staging was in response to the suggestion it might need to some sort of bigger burn as it had been suggested the ballistic path after burnout might be subject to too much first stage shutdown velocity error for the grid fins to steer it to the barge.

In any case,  thanks for pointing out that indeed the thrusters provide the ullage for boostback. So at least in theory it could do such a 90 degree burn as far as ullage is concerned, even if it is never attempted or some other reason may exist to make it impractical.

I think it is likely the grid fins' crossrange glide (albeit poor) should be able to handle any reasonable velocity (therefore  ballistic descent path) error after staging anyway. But in case not, to get the ballistic path close enough to the ballpark for the grid fins to handle the rest of the way, was suggesting a very brief 90 degree course correction burn might be more effective (less propellant) than a retrograde (or posigrade depending on the error) burn after staging.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jimmy Murdok on 02/10/2016 08:57 AM
I vote for opening the legs at high altitude when low friction; learn/get data on the descent with high drag. If under control try landing, otherwise splash. At some point the legs should be used to save fuel, this is the perfect opportunity.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mike_1179 on 02/10/2016 09:55 AM
I vote for opening the legs at high altitude when low friction; learn/get data on the descent with high drag. If under control try landing, otherwise splash. At some point the legs should be used to save fuel, this is the perfect opportunity.

The legs require a redesign to allow them to be forced open and locked in a partially deployed state. You're saying this was done already?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/10/2016 12:14 PM
We do know that F9FT has "upgraded legs".  We don't know what exactly that means, but folks tend to speculate.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Herb Schaltegger on 02/10/2016 12:51 PM

We do know that F9FT has "upgraded legs".  We don't know what exactly that means, but folks tend to speculate.

Understatement of the century with regard to SpaceX threads.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Fan Boi on 02/10/2016 12:53 PM
I don't think they will deploy the legs until the last moment, just like normal. Opening them high up would make an aerodynamic nightmare, not to mention it would likely decrease the authority of the grid fins since they would be in disturbed air from the legs. 2 cents...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rpapo on 02/10/2016 01:07 PM
I don't think they will deploy the legs until the last moment, just like normal. Opening them high up would make an aerodynamic nightmare, not to mention it would likely decrease the authority of the grid fins since they would be in disturbed air from the legs. 2 cents...
And, as has been seen already in video, the current leg extension mechanism does not have enough authority (impedence).  Neither do the legs extend uniformly, and this matters aerodynamically.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Fan Boi on 02/10/2016 01:16 PM
But deploying them in a vacuum would increase the effective pressure of deployment gas, and would make any uneven deployment a non-issue I would think. It is the ride down with legs open that gives me pause. 2 cents again...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/10/2016 01:25 PM
legs first seems to be aerodynamically unstable. You want center of gravity first and center of aerodynamic drag behind. In the direction of travel frame of reference.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jimmy Murdok on 02/10/2016 01:33 PM
The legs require a redesign to allow them to be forced open and locked in a partially deployed state. You're saying this was done already?
I'm speculating, but the bird is so heavy that landing fuel might scarce. In case there is no fuel for standard brake, it might be the only option.
Still is quite possible that partial deployment is required for stability. Statement for that?

Edit: when Elon confirmed about leg brake he spoke about SES-9 https://twitter.com/elonmusk/status/536268250620125185
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/10/2016 01:36 PM
Here's a back of the envelope calculation indicating that SpaceX will not need to cancel the re-entry burn entirely, but will need to make it about 9 seconds shorter than normal:

First, we know the goal of the new trajectory is to decrease the time to service by a month, from http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/ "The goal is to reduce by a month or more the time it would otherwise take SES-9 to begin generating revenue."

So one less month of thrusting.  How much delta-V is that?  The XIPS thruster has a force of 165 mN when used in orbit-raising mode: ( http://www2.l-3com.com/eti/product_lines_electric_propulsion.htm ).  How much mass does the satellte have at this point?  From the fact that the chemical prop can get to a 24 hour (but not circular orbit), we guess about 1200 m/s delta-V.  At an ISP of 220 (typical for hydrazine), 1200 m/s implies a mass ratio of 1.744, so if SES-9 starts at 5330 kg it's about 3056 kg after the chemical engine burn.

Now 0.165 Newtons acting on 3056 kg gives 4.66 m/s per day of operation.  That's 140 m/s over a month.  So we guess the modified trajectory offers 140 m/s more.  Near the end of the first stage burn, the rocket should be accelerating at 4-5 Gs, or 40-50 m/s/s.  So SpaceX will run the 9 engines for 3 seconds longer than before.  This leaves less fuel for the re-entry burn.  Since this burn is made with 3 engines, not 9, it will therefore be 9 seconds shorter. 

Since the re-entry burn is longer than 9 seconds, (21 seconds on ORB-2, see http://spaceflight101.com/falcon-9-orbcomm-flight2/reconstruction-milestone-falcon-9-flight-with-eleven-og2-satellites/ ) SpaceX will not need to delete it entirely, just make it shorter. Or they could use 2 engines instead of 3 and keep it roughly the same length.

EDIT: fixed naming - changed retro burn to re-entry burn.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/10/2016 01:51 PM
you've got reentry and retro burn used in the comment. I assume you mean just reentry.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hrissan on 02/10/2016 01:58 PM
I don't think they will deploy the legs until the last moment, just like normal. Opening them high up would make an aerodynamic nightmare, not to mention it would likely decrease the authority of the grid fins since they would be in disturbed air from the legs. 2 cents...
Well, at the atmospheric entrance, the authority of airflow over open legs would be like an authority of hungry grizzly bear over legs of cooked Christmas goose. :)

**could not resist
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: launchwatcher on 02/10/2016 02:33 PM
That may or may not be enough to hole the barge badly enough to make her irreparable.
Shipyards can work wonders.   The USS Cole survived a 40-by-60 foot hole in her port side and was repaired and returned to duty.  If it were to make a hole, I don't see an empty F9 making a hole much bigger than 12 feet in diameter.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/10/2016 02:57 PM
All this concern trolling about the poor ASDS.  I repeat: if they get close enough to make a dent in the ASDS they will be overjoyed.  It is such a hard target to hit!

Adding some (slightly more) fact-based discussion: Elon's leg tweet was, "Using legs as air brakes to drop terminal velocity in half requires slight redesign & more data. Maybe flight 21."  Everyone seems to agree that the F9FT leg upgrade was only "slight", so let's assume that's actually done.  It's entirely possible they may use this flight to gather "more data", regardless of actual landing.  For example: preserve the full reentry burn (or close to it) even at the cost of having to skip the landing burn.  This would let them get data on high-altitude leg deployment/aerodynamics, which is probably more interesting to them than revisiting the grasshopper flight regime (final descent) again.

(Since the idea behind early deployment is to get extra help on drag, a "full reentry burn" would still be shorter than normal in order to set up the appropriate flight environment for the test.)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/10/2016 03:02 PM


"Using legs as air brakes to drop terminal velocity in half requires slight redesign & more data. Maybe flight 21."

So redesign might mean deploying them half way so the stage would look like a shuttlecock. In other words legs angled backwards to direction of travel?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/10/2016 04:32 PM
As I said before, the above is all the information we have.  Everything else is speculation.

But I believe that a closer look at the leg mechanisms of Orbcomm flight 2 didn't indicate any obvious changes that would allow half-deployment.  So if you think that is a necessary part of the "slight redesign" I'm afraid SES-9 won't be your bird.

I'm personally intrigued by the suggestion that the legs might be fully deployed above the sensible atmosphere, so the weak deployment forces aren't an issue.  I don't think the shuttlecock effect will be all that bad --- there's a *lot* of weight on the engine side, so you might manage to retain passive stability even with legs fully deployed.  Someone calculated that the cg of the whole dry stage is not much above the engines.  Even if passive stability in this configuration is marginal, the grid fins do have some active control authority.  It may be enough for SpaceX to give it a go.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: nadreck on 02/10/2016 04:43 PM
Not that I actually know the cross section area of the legs, but it is at least a substantial fraction of the 10.52 m2 of the rest of the stage. Increasing that area substantially before encountering much atmosphere should  slow the craft proportionally more quickly while spreading out the heat and structural loading proportionally as well. This would mean an increase in the manageable atmospheric entry velocity by a ratio equal to the square root of the ratio of the new area to the old area. Or so my simplistic view says. So if the maximum survivable speed was 1000 m/s before and the area goes up by 50% then the maximum survivable speed should be 1,225m/s, at 100% more area then it would be root 2 or 1,414m/s.

Of course this flight might provide us with some confirmation of what the actual maximum speed is higher (or lower) than.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/10/2016 04:44 PM
They have been taking a fair amount of time between launches of the newest version of the vehicle, maybe new legs are part of the scramble, as well as a new flight profile. SpaceX does not seem to worry about changing more than one thing at a time.

Matthew
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 02/10/2016 04:52 PM
...it sounds like for the SES-9 landing attempt, in order to sacrifice a lot of landing fuel for the payload's mission, it's not going to do a  boostback burn, or a re-entry burn.  A very fast natural ballistic descent until the grid fins start to become effective. A  sort of Hail Mary that it can survive, with the grid fins aerodynamically steering it to the ASDS, with the only burn being for landing.

I don't believe this would be survivable, without an entry burn.  We're looking at, what, a Mach 9 entry on this kind of flight profile?  I refer you to some tests done late in the X-15 program, as part of a project to try and add a hypersonic ramjet onto the experimental aircraft.

On one of the later fights, when the X-15 itself had been covered by a temporary ablative coating (the flights of the "white X-15"), they did a flat-altitude (i.e., not a high-altitude to-the edge-of-space profile), high-speed run topping out at about Mach 6, with some of the flight ramjet attachment hardware and a dummy ramjet casing attached to the vehicle.

The ramjet hardware burned through and was severely damaged, as was the dummy ramjet casing, even though many of the parts were supposedly hardened against high heat loads.

I'm pretty certain that a stage one entry, octaweb forward, with no entry burn, at Mach 9 would inevitably result in the destruction of the stage.  I imagine the fabric engine housing covers would burn through first, followed by the octaweb structural members, and the interior of the octaweb would come apart under high deceleration and heating conditions, which (not coincidentally) come right around the same time.  This would lead quickly to the RUD of the entire stage.

So, I believe that on any Falcon 9 or Falcon Heavy flight profile, you have to have enough gas left in the tanks for both an entry burn and a landing burn, if you want to try to recover the stage.

Now, a short entry burn is a possibility -- the primary thing the entry burn has to do is protect the stage from entry heating at high Mach numbers; the amount of delta-V taken out of the approach is less of a limiting factor than providing protection during the high heating portion of the entry.  So, as long as you're burning through the high heating phase, you can try to design a remaining approach and landing profile based on your speed and trajectory state coming out of the entry burn.

If there is not a potentially solvable solution for that post-entry-burn navigation state, then SpaceX wouldn't even attempt a stage recovery.  The fact that they're going to try it rather strongly implies to me that there has to be a solvable approach trajectory that is within the envelope of what ought be left in the tanks at that point.

The only question in my mind is whether or not the nav system on the stage has an alternate solution tree for the case of fuel/oxidizer depletion during the landing burn.  At some point, obviously, it is too late to do anything except just continue on the present trajectory -- a dead man's zone, so to speak.  But, does the nav system recognize depletion cut-off early in the burn such that it ditches into the ocean a safe distance from the ASDS and its support ship(s)?  The FTS is disabled by the time the landing burn starts, remember -- for good reason, too, you don't want flaming shreds of a Falcon stage raining down onto the ASDS and its support vehicles.

I wouldn't think it would be that difficult to build such an abort logic tree into the nav system, there's just no way to tell if SpaceX has done so or not...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: luinil on 02/10/2016 05:18 PM
There is a lot of speculation, but we just know that SpaceX sacrificed the return to launch site, they might still have the three burns, the first one being just shorter without rtls.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/10/2016 05:34 PM
There is a lot of speculation, but we just know that SpaceX sacrificed the return to launch site, they might still have the three burns, the first one being just shorter without rtls.
No, I think the SES-9 plan was previously already an ASDS plan. Just not as fuel starved.

The Other Doug: Are you SURE there is no survivable scenario without a reentry burn?

I'm not sure I am really clear on how density increases as you descend, nor how the speed profile would change as you descend. But are there not some scenarios in which you slow down enough gradually enough that you don't experience the heating you would at lower altitudes?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: meekGee on 02/10/2016 05:41 PM
So an anemic or non-existent reentry burn, and a normal landing burn - this seems the me to the likeliest interpretation.

I wonder if anemic means short, or singled-engined.

If it works, it has good implications for future reusability - it means they have more margin then they thought.  Maybe the stage get's overworked though, shortening its future life.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/10/2016 05:43 PM
...it sounds like for the SES-9 landing attempt, in order to sacrifice a lot of landing fuel for the payload's mission, it's not going to do a  boostback burn, or a re-entry burn.  A very fast natural ballistic descent until the grid fins start to become effective. A  sort of Hail Mary that it can survive, with the grid fins aerodynamically steering it to the ASDS, with the only burn being for landing.

I don't believe this would be survivable, without an entry burn.  We're looking at, what, a Mach 9 entry on this kind of flight profile?  I refer you to some tests done late in the X-15 program, as part of a project to try and add a hypersonic ramjet onto the experimental aircraft.

Agreed.

Quote
Now, a short entry burn is a possibility -- the primary thing the entry burn has to do is protect the stage from entry heating at high Mach numbers; the amount of delta-V taken out of the approach is less of a limiting factor than providing protection during the high heating portion of the entry.  So, as long as you're burning through the high heating phase, you can try to design a remaining approach and landing profile based on your speed and trajectory state coming out of the entry burn.

Depending on the nature of the enveloping plume in retropropulsion, and if they can start the engines in EI, and if the vehicle can withstand the thermal and deceleration environment, plus if enough control authority is present for the maneuver, they might be able to use the plasma wake to additionally decelerate the craft during a brief braking burn.

The addition issues are the timing of the burn and what happens at the conclusion of the burn with flow reconnection - thermal/stress/aeroloads/stagnation. How much can a rocket going backwards take? Certain TPS additions might allow lower/greater deceleration.

Quote
If there is not a potentially solvable solution for that post-entry-burn navigation state, then SpaceX wouldn't even attempt a stage recovery.  The fact that they're going to try it rather strongly implies to me that there has to be a solvable approach trajectory that is within the envelope of what ought be left in the tanks at that point.

Not a problem AFAIK.

Quote
The only question in my mind is whether or not the nav system on the stage has an alternate solution tree for the case of fuel/oxidizer depletion during the landing burn.  At some point, obviously, it is too late to do anything except just continue on the present trajectory -- a dead man's zone, so to speak.  But, does the nav system recognize depletion cut-off early in the burn such that it ditches into the ocean a safe distance from the ASDS and its support ship(s)?  The FTS is disabled by the time the landing burn starts, remember -- for good reason, too, you don't want flaming shreds of a Falcon stage raining down onto the ASDS and its support vehicles.

AFAIK, they have safety and NAV already handed for this case. And good models for prop exhaustion.

Quote
I wouldn't think it would be that difficult to build such an abort logic tree into the nav system, there's just no way to tell if SpaceX has done so or not...

Yes. And I'm sure they had to explain it for range safety to allow a land landing.

They even have props exhaustion and NAV figured out. Where it looks still WIP is terminal GNC stability.

There is a lot of speculation, but we just know that SpaceX sacrificed the return to launch site, they might still have the three burns, the first one being just shorter without rtls.
No, I think the SES-9 plan was previously already an ASDS plan. Just not as fuel starved.

The Other Doug: Are you SURE there is no survivable scenario without a reentry burn?

I'm not sure I am really clear on how density increases as you descend, nor how the speed profile would change as you descend. But are there not some scenarios in which you slow down enough gradually enough that you don't experience the heating you would at lower altitudes?

His issue is real. What we all don't know is how much margin remains for the booster to handle recovery.

Everyone is focused on booster exhaustion though, as they've gotten used to F9US being a bit of a wimp. What if they trim US/shroud mass and tweak props/engine for more specific flight profile and eek out  6-7% more delta-V?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/10/2016 05:53 PM

Everyone is focused on booster exhaustion though, as they've gotten used to F9US being a bit of a wimp. What if they trim US/shroud mass and tweak props/engine for more specific flight profile and eek out  6-7% more delta-V?

They would have done that with the existing upgrade.  It is an upper stage, there isn't much to tweak trajectory wise since it is out of the atmosphere. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: bstrong on 02/10/2016 05:58 PM
I hope NASA has their tracking plane up for this one. There should be some interesting new data points on supersonic retropropulsion, one way or another.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/10/2016 06:15 PM

Everyone is focused on booster exhaustion though, as they've gotten used to F9US being a bit of a wimp. What if they trim US/shroud mass and tweak props/engine for more specific flight profile and eek out  6-7% more delta-V?

They would have done that with the existing upgrade.

You're right (as usual) in that they've already optimized the US drymass just to get current performance numbers. So you'd have to leave out something major that they wouldn't use on this mission along.

The shroud is much heavier than it needs to be. First best obvious source of mass to trim.

Quote

It is an upper stage, there isn't much to tweak trajectory wise since it is out of the atmosphere.

Nope, few options. As Steve upthread pointed out, a three-burn option to optimize losses. On the other extreme, you leave off restart capability and single burn with circularization handled by the payload, but hard to imagine that would gain enough either.

If you knew your flight profile had a narrow excursion, and your thrust variation likewise, you could trim thrust structures around exact needs/margins for the special case. Might get 1-2% for that.

Trying to think out of the box like they do.

Thanks for the exercise.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/10/2016 06:47 PM
Just finished reading the last 5 or so pages to get back to the top of this thread.  A few comments that accumulated-

I’ve seen multiple reasons given for doing a re-entry burn; Lower speed / pressure / heating, targeting adjustments, creating a shield being the main ones.  There seems to me to be another one, that being that during the initial moments of re-entry forces build very quickly and the authority of the N2 jets or (nearly) airless grid fins is not enough to make attitude adjustments quickly enough to assure that the stage is tail first a few moments later when the pressure and heating build up. You'd hate to have the blast acting on the side of the tank. The Merlin(s) are the only device they have that has enough authority to make quick attitude adjustments at that point in the flight.  My guess is that they’ll use one Merlin for what they calculatedly guess to be the minimum time until the grid fins can take over steering.

I’ve seen some suggestions that the Merlin is tough because it lived through the ingestion of tank parts.  My thought is that ingesting the parts doesn’t necessarily mean that the parts went through the pump and engine.  The more likely scenario seems that a larger part was ingested into and lodged in the feed plumbing or strainer and caused reduced flow and / or unstable fluctuating flow which would naturally lead to thrust fluctuations.

Some have suggested that the legs be opened higher to generate more drag earlier.  I believe that this line of thought was first suggested by Elon a year ago in the reddit AMA.  Question for someone that’s been through some aerodynamics lessons: Right now the four grid fins are directly aligned with the four landing legs.  Is this the way they’d be likely to arrange them if the goal was to steer with the legs out or would a better configuration be with the interstage and grid fins clocked 45 degrees to put the fins out of alignment with the legs?

Regarding the damage to the ASDS, sinking, etc.- Even if the ASDS were to be struck dead center by an empty terminal velocity F9 I doubt it would leave much of a hole in the deck.  Deck extensions or equipment containers yea, that would leave very photogenic damage, but the Marmac barge itself is one tough beast.   And as for as some have suggested it being sunk, no chance.  Even a hole 50 feet in diameter wouldn’t do much to sink it as it is composed of water tight compartments each approximating a 20 foot cube.  Just pull it back into one of many suitable shipyards and the guys with Carhart clothing will sort it out.

Folks are forgetting that even before landing legs, before the ASDS, before most of us were aware of it SpaceX was doing re-entry testing.  This will be more of that, a high entry speed with little propellant.  Just the same experiment with higher numbers to see where the boundaries are.  And some potential that there might be some rockets red glare and legs opening in midair on the far side of the experiment.

Edit / add: If something came loose in Orbcomm-2's 1st stage fuel tank then that should be enough to start rabid internet speculation that the CRS-7 failure discussion should be re-hashed with the speculative theme of that same component having come loose in the 2nd stage oxidizer tank right?  Objection: strut tested below spec in the lab.  Hmm...  Nah.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: yokem55 on 02/10/2016 08:14 PM
I hope NASA has their tracking plane up for this one. There should be some interesting new data points on supersonic retropropulsion, one way or another.
I doubt NASA has any further tracking flights planned. They got the data they were looking for to model hypersonic retro-propulsion for Mars, and now they are done with that mini program.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/10/2016 08:35 PM

The shroud is much heavier than it needs to be. First best obvious source of mass to trim.


Kind of hard without a requal
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: bstrong on 02/10/2016 08:39 PM
I hope NASA has their tracking plane up for this one. There should be some interesting new data points on supersonic retropropulsion, one way or another.
I doubt NASA has any further tracking flights planned. They got the data they were looking for to model hypersonic retro-propulsion for Mars, and now they are done with that mini program.

It was mentioned in the FY17 budget request that just came out. Doesn't specifically say they will do more tracking flights, but the program looks like it is ongoing:

https://www.nasa.gov/sites/default/files/atoms/files/fy_2017_budget_estimates.pdf

Quote
To better understand the utility of supersonic retrorocket propulsion under Mars entry conditions, Space
Technology will continue to evaluate flight data from SpaceX Falcon 9 first stage landing demonstrations.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/10/2016 08:42 PM
"Flight data" might mean just SpaceX sharing data with NASA.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/10/2016 08:46 PM
I wonder if anemic means short, or singled-engined.

It would be great to SpaceX's simulations of the shield plume using one or two engines.
I assume from your comment that the reentry burn is usually 3 engined?
I hope NASA takes an infra red view again.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/10/2016 09:18 PM
I  can't remember where I saw it - maybe in a Mars entry modelling piece - where it was suggested that the plume shielding benefits were better with engines on the outside of the entry vehicle.
I could have misrembered that but it  also seemed that the plasma had hotspots elsewhere. On a long stage just although heating may be limited near the engines it might not mean it's limited elsewhere.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/11/2016 03:22 AM
I wonder if anemic means short, or singled-engined.

It would be great to SpaceX's simulations of the shield plume using one or two engines.
I assume from your comment that the reentry burn is usually 3 engined?
I hope NASA takes an infra red view again.

I thought the reentry burn was only the centre engine?

Relevant review paper: http://www.ssdl.gatech.edu/papers/conferencePapers/IEEE-2008-1246.pdf
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: malu5531 on 02/11/2016 06:34 AM
I  can't remember where I saw it - maybe in a Mars entry modelling piece - where it was suggested that the plume shielding benefits were better with engines on the outside of the entry vehicle.
I could have misrembered that but it  also seemed that the plasma had hotspots elsewhere. On a long stage just although heating may be limited near the engines it might not mean it's limited elsewhere.

Probably in the youtube-video with Max thesis defence; https://www.youtube.com/watch?v=GQueObsIRfI
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/11/2016 06:45 AM
That thesis defense is interesting. The fuel savings due to increased drag was indicated as ~5%. I doubt though that this saving justifies modeling the whole design around it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: macpacheco on 02/11/2016 07:19 AM
I thought the reentry burn was only the centre engine?

Relevant review paper: http://www.ssdl.gatech.edu/papers/conferencePapers/IEEE-2008-1246.pdf

Nope, AFAIK, the boostback and re-entry burns are 3 engine ones, and the landing is a single engine one.
That has been stated in NSF a few times by people way more knowledgeable than me.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/11/2016 07:51 AM
no
I wonder if anemic means short, or singled-engined.

It would be great to SpaceX's simulations of the shield plume using one or two engines.
I assume from your comment that the reentry burn is usually 3 engined?
I hope NASA takes an infra red view again.

I thought the reentry burn was only the centre engine?

Relevant review paper: http://www.ssdl.gatech.edu/papers/conferencePapers/IEEE-2008-1246.pdf

Thanks - that does mention the benefit of using engines at the periphery but if I understand it correctly they need to do more research for other vehicle  configurations and I guess long rocket stages fall into that category.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/11/2016 12:54 PM
I think the safe return environment is not exactly boundedby a line. It must have a thick border where they don't quite know if they will survive, or if will return in a reusable state. May be, they can have a trajectory where they can get back the stage but not re fly it. And this is a reasonable opportunity to explore that threshold of usability. Crazy risky, but probably very interesting.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/11/2016 01:50 PM
I think the safe return environment is not exactly boundedby a line. It must have a thick border where they don't quite know if they will survive, or if will return in a reusable state. May be, they can have a trajectory where they can get back the stage but not re fly it. And this is a reasonable opportunity to explore that threshold of usability. Crazy risky, but probably very interesting.
Not crazy risky, almost no risk since the alternative is just operating like every other launch provider.

As far as not being able to fly it again, that should be not able to fly it again /without design tweaks/. They are just learning this. They want to do reentry from orbit for an upper stage eventually (not likely to be kerolox), so they want to keep pushing this as much as they can. I guess this flight is a good opportunity for that.

Also, remember that the stage must be operating in order for them to recover it, so it's a little hard to imagine a scenario where the whole stage cannot be flown again, though no doubt there'd be varying degrees of wear and tear depending on the trajectory.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rsdavis9 on 02/11/2016 01:54 PM
I could see getting the stage back but having heat damage to the metal surfaces such that they wouldn't trust the stage for a reflight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/11/2016 04:32 PM
I would have thought that Spacex could have modelled various reentry scenarios with the single central or two or four external engines at various throttle levels but I bet the necessarily precise fluid models eat time however good their IT.
Maybe they have come up with something new- it's not impossible.
Maybe they haven't yet started the reentry burn as late as they could - can anyone here estimate the point at which reentry heating approaches a high fraction of the operating engine temperature for this mission profile? I'd be surprised.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/11/2016 06:10 PM
(...)
Also, remember that the stage must be operating in order for them to recover it, so it's a little hard to imagine a scenario where the whole stage cannot be flown again, though no doubt there'd be varying degrees of wear and tear depending on the trajectory.
There are many reasons for it not to be reflyable. Fatigue, thermal stress, loss of thermal treatment, plastic deformation, etc. It might be able to land, since it has basically no load. It has only a fraction of propellant, no upper stage, and only need to land once. But might lose all margins and some. This is what I mean that it might not be flyable. But as you said, they might investigate what would it take to actually be so in a future design.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/11/2016 11:59 PM
(...)
Also, remember that the stage must be operating in order for them to recover it, so it's a little hard to imagine a scenario where the whole stage cannot be flown again, though no doubt there'd be varying degrees of wear and tear depending on the trajectory.
There are many reasons for it not to be reflyable. Fatigue, thermal stress, loss of thermal treatment, plastic deformation, etc. It might be able to land, since it has basically no load. It has only a fraction of propellant, no upper stage, and only need to land once. But might lose all margins and some. This is what I mean that it might not be flyable. But as you said, they might investigate what would it take to actually be so in a future design.
Yeah, but I don't find that super plausible.

On the way back, it only takes one minor system to fail in order for the launch to fail. This means you're not going to have large parts of the rocket that all experience a bunch of thermal/mechanical stress right up to the point of being unflyable (but not to the point that recovery failed) because small parts of the rocket are likely to completely fail before then. It only takes a single sticky valve on the center engine or grid fins stuck hard to one side or a leg that doesn't completely lock or a single failed strut or...

What I'm saying is that a rocket is a fragile system. It's likely to be either largely intact and in a flyable condition (perhaps after repair of some smallish things yielded beyond spec but not totally failed, i.e. the piece of that one Merlin engine on the recovered first stage that acted up after the previous flight, etc) or scattered in countless pieces across the barge, ocean, and/or landing site (like almost all of SpaceX's first stages that they have attempted recovery of).

...not that the most risk-averse customers would want to accept those first launches with their most prized payloads, but I really think the line between successful-recovery-but-unflyable and failed-recovery is very, very thin.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/12/2016 12:06 AM
Well, I speculate that any "small piece" can be replaced. But if the structural elements of the tank suffered plastic deformation, for example, it might land, but won't be re flyable. Ditto if they went above some threshold temperature.
After all, for landing the structural requirements on the top end are negligible.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/12/2016 12:11 AM
Well, I speculate that any "small piece" can be replaced. But if the structural elements of the tank suffered plastic deformation, for example, it might land, but won't be re flyable. Ditto if they went above some threshold temperature.
After all, for landing the structural requirements on the top end are negligible.
Small damages in the tank can be repaired. But you're VERY unlikely to yield the whole tank evenly past flyability without some small part of it failing entirely, killing recovery. You're going to completely fail at some stress concentration point (which could be repaired if just yielded) before large swaths become yielded.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/12/2016 12:13 AM
...Ditto if they went above some threshold temperature...
Right, and what are the odds that the temperature is SO even that it doesn't cause local hotpots to exceed total failure but does bring large swaths of the structure past flyability? I find that very unlikely.

It's like a light bulb. It either survives or it doesn't. You're really unlikely to get an in-between (besides minor failures that could be repaired).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/12/2016 03:13 AM

What I'm saying is that a rocket is a fragile system. It's likely to be either largely intact and in a flyable condition (perhaps after repair of some smallish things yielded beyond spec but not totally failed, i.e. the piece of that one Merlin engine on the recovered first stage that acted up after the previous flight, etc) or scattered in countless pieces across the barge, ocean, and/or landing site (like almost all of SpaceX's first stages that they have attempted recovery of).
The Soviet Buran orbiter made it back OK, but with damage that was too expensive to repair, so it is possible.
http://www.nasaspaceflight.com/2013/11/remembering-buran-shuttles-estranged-soviet-cousin/
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Robotbeat on 02/12/2016 03:19 AM

What I'm saying is that a rocket is a fragile system. It's likely to be either largely intact and in a flyable condition (perhaps after repair of some smallish things yielded beyond spec but not totally failed, i.e. the piece of that one Merlin engine on the recovered first stage that acted up after the previous flight, etc) or scattered in countless pieces across the barge, ocean, and/or landing site (like almost all of SpaceX's first stages that they have attempted recovery of).
The Soviet Buran orbiter made it back OK, but with damage that was too expensive to repair, so it is possible.
http://www.nasaspaceflight.com/2013/11/remembering-buran-shuttles-estranged-soviet-cousin/
Same with Shuttle, because the refurbishment costs always were more expensive than an expendable launch would've been. Kind of a different story, though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: jacqmans on 02/12/2016 08:29 AM
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rocx on 02/12/2016 09:39 AM
I suppose this is the first mission patch to ever feature a landing vessel? Has there ever been a mission patch featuring recovery facilities, such as the Shuttle Landing Facility?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Bargemanos on 02/12/2016 09:56 AM
I suppose this is the first mission patch to ever feature a landing vessel? Has there ever been a mission patch featuring recovery facilities, such as the Shuttle Landing Facility?


CRS-6 and 7 had them as well
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/12/2016 11:04 AM
so ... number of stars?  Triangle to the right of SES on the starfield?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/12/2016 11:24 AM
Triangle to the right of SES on the starfield?

Err... their logo?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Bargemanos on 02/12/2016 11:25 AM
Triangle to the right of SES on the starfield?

Err... their logo?


Correct!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevin-rf on 02/12/2016 01:12 PM
OMG, OMG, a mission patch that actually has the solar panels oriented correctly (North South, not East West)!!!!

Way to go SpaceX! We can quivel about the orbit being inclined some 60ish degrees later.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/12/2016 01:28 PM
I guess it's obvious from the patch SpaceX care a lot about trying this recovery, regards of success.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/12/2016 01:28 PM
Or the patch predates the mission profile change.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/12/2016 01:40 PM
Sure.  "Caring a lot" doesn't mean they'll actually perform a recovery.  Just that they will certainly, well, *try hard*.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Norm38 on 02/12/2016 03:04 PM
So one less month of thrusting.  How much delta-V is that?  The XIPS thruster has a force of 165 mN when used in orbit-raising mode: ( http://www2.l-3com.com/eti/product_lines_electric_propulsion.htm ).  How much mass does the satellte have at this point?  From the fact that the chemical prop can get to a 24 hour (but not circular orbit), we guess about 1200 m/s delta-V.  At an ISP of 220 (typical for hydrazine), 1200 m/s implies a mass ratio of 1.744, so if SES-9 starts at 5330 kg it's about 3056 kg after the chemical engine burn.

Now 0.165 Newtons acting on 3056 kg gives 4.66 m/s per day of operation.  That's 140 m/s over a month.  So we guess the modified trajectory offers 140 m/s more.  Near the end of the first stage burn, the rocket should be accelerating at 4-5 Gs, or 40-50 m/s/s.  So SpaceX will run the 9 engines for 3 seconds longer than before.  This leaves less fuel for the re-entry burn.  Since this burn is made with 3 engines, not 9, it will therefore be 9 seconds shorter.

I have a question that I didn't see asked.  With the original trajectory, SES-9 would have provided 140m/s and burned 2274kg of propellant, per Lou's numbers.
So now that the F9 is providing that 140m/s, does that mean the SES-9 will have the extra 2274kg propellant for more service time in orbit, or that it will weigh 2274kg less on launch?  Or some split?

If SES-9 weighs less, doesn't that affect the amount of fuel F9 has left for the recovery burns?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: gongora on 02/12/2016 03:33 PM
So one less month of thrusting.  How much delta-V is that?  The XIPS thruster has a force of 165 mN when used in orbit-raising mode: ( http://www2.l-3com.com/eti/product_lines_electric_propulsion.htm ).  How much mass does the satellte have at this point?  From the fact that the chemical prop can get to a 24 hour (but not circular orbit), we guess about 1200 m/s delta-V.  At an ISP of 220 (typical for hydrazine), 1200 m/s implies a mass ratio of 1.744, so if SES-9 starts at 5330 kg it's about 3056 kg after the chemical engine burn.

Now 0.165 Newtons acting on 3056 kg gives 4.66 m/s per day of operation.  That's 140 m/s over a month.  So we guess the modified trajectory offers 140 m/s more.  Near the end of the first stage burn, the rocket should be accelerating at 4-5 Gs, or 40-50 m/s/s.  So SpaceX will run the 9 engines for 3 seconds longer than before.  This leaves less fuel for the re-entry burn.  Since this burn is made with 3 engines, not 9, it will therefore be 9 seconds shorter.

I have a question that I didn't see asked.  With the original trajectory, SES-9 would have provided 140m/s and burned 2274kg of propellant, per Lou's numbers.
So now that the F9 is providing that 140m/s, does that mean the SES-9 will have the extra 2274kg propellant for more service time in orbit, or that it will weigh 2274kg less on launch?  Or some split?

If SES-9 weighs less, doesn't that affect the amount of fuel F9 has left for the recovery burns?

Lou was saying the satellite would provide 1200m/s with its chemical propulsion system using that amount of propellant, then the smaller and more efficient thrusters would have to take over.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Norm38 on 02/12/2016 04:00 PM
^^^ Yes, I see my error, thanks.  140m/s isn't much fuel for an ion thruster, (~2kg?)  so I assume that will be extra station keeping reserve.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/12/2016 05:48 PM

thought SES-9 was processed, fueled and stored ready for launch.  Confusing


It is.  The launch/flight profile is independent of that
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LouScheffer on 02/12/2016 05:54 PM
^^^ Yes, I see my error, thanks.  140m/s isn't much fuel for an ion thruster, (~2kg?)  so I assume that will be extra station keeping reserve.
Yes, that's what I would guess.  Station keeping takes about 50 m/s per year, so if this plan works, in addition to taking a month less to go into service, it should have almost 3 years more station keeping fuel.  (Although with ion thrusters, I don't know if station keeping fuel is ever the lifetime limiting factor any more.)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Roy_H on 02/13/2016 03:43 PM
Does anybody know if the legs and grid fins will be removed? I would think that if they are going to splash it in the drink anyway, there is no reason not to save the weight and cost.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Coastal Ron on 02/13/2016 04:07 PM
Does anybody know if the legs and grid fins will be removed? I would think that if they are going to splash it in the drink anyway, there is no reason not to save the weight and cost.

It depends on what re-entry objectives they want to test.

For instance, if they feel there will be enough fuel to attempt a controlled re-entry, then they would likely keep the grid fins on since they provide directional control once aerodynamic effects come into play.  But if they are not planning on landing the stage on a barge, and will just assume a water landing, then it would make no sense to attach the landing legs.  Legs are an option, and are not required for the primary task of moving payloads to space.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/13/2016 04:15 PM
Does anybody know if the legs and grid fins will be removed? I would think that if they are going to splash it in the drink anyway, there is no reason not to save the weight and cost.

If they are still going for the barge (no matter the reduced probability of success), *of course* they will keep them.

Their performance hit is not as significant as people tend to assume, they are only on the first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: IntoTheVoid on 02/13/2016 04:46 PM
Does anybody know if the legs and grid fins will be removed? I would think that if they are going to splash it in the drink anyway, there is no reason not to save the weight and cost.

anyone thinking grin fins on, no legs and (projected) location on water is the objective?

No

Confirmed by SES that the SES-9 launch will skip first stage recovery.

http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

They are risking recovery, not abandoning. From the same article...
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/13/2016 05:55 PM
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position. http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

What I don't get about that statement is how the chances of success can be "much less", when you're trying to land a rocket with an 18m leg span on a barge 52m wide. Sounds to me like you either can or you can't. So if just 4 days ago there was only "hope", that implies SpaceX is still working on the calculations to assess the new margins of error. Frankly I'm a bit worried they might try to cut it too close. Anyone with any roots in Jacksonville knows the infamous Lynyrd Skynyrd plane crash happened because the plane ran out of gas (the air/fuel mix was turned up too rich because the plane had been backfiring). We don't even drive to the grocery store around here with less than 1/8th of a tank.

BTW, not attaching the legs if they choose to abandon recovery would add to the recalculations, unless that scenario has been precalculated. The legs weigh about 2100kg or 2.3 US tons (2.1 UK tons for our friends across the pond).
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/13/2016 05:59 PM
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position. http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

What I don't get about that statement is how the chances of success can be "much less", when you're trying to land a rocket with an 18m leg span on a barge 52m wide. Sounds to me like you either can or you can't. So if just 4 days ago there was only "hope", that implies SpaceX is still working on the calculations to assess the new margins of error. Frankly I'm a bit worried they might try to cut it too close. Anyone with any roots in Jacksonville knows the infamous Lynyrd Skynyrd plane crash happened because the plane ran out of gas (the air/fuel mix was turned up too rich because the plane had been backfiring). We don't even drive to the grocery store around here with less than 1/8th of a tank.

BTW, not attaching the legs if they choose to abandon recovery would add to the recalculations, unless that scenario has been precalculated. The legs weigh about 2100kg or 2.3 US tons (2.1 UK tons for our friends across the pond).

The issue is the reentry burn being shorter or non existant.... if the stage survives reentry the chances of landing are about the same as before... worse due to the possibility of damage that is not realised from hotter reentry[1], better due to them improving their approach based on learnings from previous attempts.

1 - many in the forum are discounting this saying that there is not much likelyhood of damage that would cause the stage to malfunction but not break up
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Nomadd on 02/13/2016 06:09 PM
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position. http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

What I don't get about that statement is how the chances of success can be "much less", when you're trying to land a rocket with an 18m leg span on a barge 52m wide. Sounds to me like you either can or you can't. So if just 4 days ago there was only "hope", that implies SpaceX is still working on the calculations to assess the new margins of error. Frankly I'm a bit worried they might try to cut it too close. Anyone with any roots in Jacksonville knows the infamous Lynyrd Skynyrd plane crash happened because the plane ran out of gas (the air/fuel mix was turned up too rich because the plane had been backfiring). We don't even drive to the grocery store around here with less than 1/8th of a tank.

BTW, not attaching the legs if they choose to abandon recovery would add to the recalculations, unless that scenario has been precalculated. The legs weigh about 2100kg or 2.3 US tons (2.1 UK tons for our friends across the pond).
There are more things to consider than fuel reserves.
 Lower fuel after higher staging and higher speed means less re-entry braking and much higher re-entry speed. The greater uncertainty is partly because they don't know for sure how much punishment the stage can take.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/13/2016 07:58 PM
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position. http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

What I don't get about that statement is how the chances of success can be "much less", when you're trying to land a rocket with an 18m leg span on a barge 52m wide. Sounds to me like you either can or you can't. So if just 4 days ago there was only "hope", that implies SpaceX is still working on the calculations to assess the new margins of error.

In case you missed it, LouScheffer did some good BOTE calculations upthread estimating that the braking burn may be reduced from 21 seconds in length to about 12 seconds based on the additional deltaV to be given to the payload.

http://forum.nasaspaceflight.com/index.php?topic=34077.msg1490085#msg1490085

That reduction in braking burn length means the stage will be coming in "hotter" with lower chance of survival.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/13/2016 08:44 PM
Am I the only one who can't wait for the 24th? This sounds like a huge mission as far as capability, survivability, and payload. I'll bring the popcorn!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cro-magnon gramps on 02/13/2016 08:50 PM
Am I the only one who can't wait for the 24th? This sounds like a huge mission as far as capability, survivability, and payload. I'll bring the popcorn!

I got the peanuts and the Rp-1... perhaps ChefPat can bring his launch day pie  ;D
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/13/2016 09:57 PM
Quote
One industry official familiar with the SES-9 mission said Hawthorne, California-based SpaceX has not abandoned hope of recovering the first stage after a landing on an offshore platform positioned for the mission. But the chances of success are much less given the launch trajectory agreed to with SES to reduce the time to arrival at its operating position. http://spacenews.com/ses-applauds-spacexs-willingness-to-sacrifice-falcon-9-first-stage-recovery-for-main-satelilte-mission/

What I don't get about that statement is how the chances of success can be "much less", when you're trying to land a rocket with an 18m leg span on a barge 52m wide. Sounds to me like you either can or you can't. So if just 4 days ago there was only "hope", that implies SpaceX is still working on the calculations to assess the new margins of error.

In case you missed it, LouScheffer did some good BOTE calculations upthread estimating that the braking burn may be reduced from 21 seconds in length to about 12 seconds based on the additional deltaV to be given to the payload.

http://forum.nasaspaceflight.com/index.php?topic=34077.msg1490085#msg1490085

That reduction in braking burn length means the stage will be coming in "hotter" with lower chance of survival.
Reentry burn not braking burn. Literally "lower, faster, hotter".
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Avron on 02/13/2016 10:15 PM
Florida today says Barge landing is expected https://t.co/F8Q1d4XJbG
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/13/2016 10:42 PM
Quote
Reentry burn not braking burn. Literally "lower, faster, hotter".

So, if you do a burn at reentry for the purpose of braking, is it no longer a braking burn?  ???
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/13/2016 10:45 PM
Quote
Reentry burn not braking burn. Literally "lower, faster, hotter".

So, if you do a burn at reentry for the purpose of braking, is it no longer a braking burn?  ???

Boostback, reentry, braking. Unless you wish to be a lawyer to blur distinction. They all brake.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/13/2016 10:50 PM
Quote
Reentry burn not braking burn. Literally "lower, faster, hotter".

So, if you do a burn at reentry for the purpose of braking, is it no longer a braking burn?  ???

Boostback, reentry, braking. Unless you wish to be a lawyer to blur distinction. They all brake.

OK, the *reentry* burn will likely be about 9 seconds shorter according to LouScheffer's calcs.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CJ on 02/13/2016 11:52 PM
Normally, the reentry burn (the one that's most likely to be shortened for SES-9) uses 3 engines (If I'm remembering correctly?). The burn has two purposes, if I remember right; braking, plus using the exhaust plume to diminish reentry heating.

My question is, would it, under these circumstances, be possible that SpaceX might decide to use a single-engine but 3x longer reentry burn? Would that be of any advantage? (I'm thinking of the usefulness of the plume regarding diminishing the compression heating of reentry)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/14/2016 12:25 AM
I'll be really surprised if the re-entry burn can be shortened, because it normally takes the launcher through transonic speeds or around Mach 1 during the last few seconds, and the grid fins don't operate as effectively if at all when surrounded by the shock waves of transonic speeds, so the fins can't take over the job of the burn to keep the vehicle oriented.

Alternatively, the boostback burn is designed to be modifiable, dependent on fuel availability and target location for each flight. For a barge landing Elon Musk has already tweeted that lateral velocity doesn't need to be zeroed out.

It sounds possible that the landing burn can also be modified with the changes in the legs for F9 FT. I think the legs were already designed to contribute to deceleration, and now they can be opened earlier to do so. They are also designed to provide additional aerodynamic stability when deployed, and do not "destabilize" the vehicle as someone suggested earlier.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/14/2016 02:10 AM
Quote
Alternatively, the boostback burn is designed to be modifiable, dependent on fuel availability and target location for each flight.

Or eliminated entirely on a severely constrained mission, which this is. I would expect to see the ASDS quite far downrange, consistent with no boostback burn at all, only a reentry burn.

AIUI, that's the plan for future FH cores, so we might see a recovery profile that's a "trial run" for FH core recoveries.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/14/2016 02:22 AM
I can see that happening. A couple of people have called it a ballistic trajectory. I think initially it will be aimed toward North Korea. Looking forward to another barge/tug/Go Quest tracking adventure as much as to the launch/landing, maybe even more since it will be ongoing for several days.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/14/2016 02:37 AM
One clue to recovery trajectory will be how many days before launch the ASDS leaves port. Farther downrange recovery means the armada has to head out sooner. My guess is 5-7 days prior, which could be as early as a Wednesday 17th departure for a launch on the 24th.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/14/2016 03:06 AM
Normally, the reentry burn (the one that's most likely to be shortened for SES-9) uses 3 engines (If I'm remembering correctly?).

Nope, that's the boostback burn with three engines, to cancel/reverse the downrange horizontal component. Three because you need considerable (bordering hypersonic) velocity to absorb.

Quote
The burn has two purposes, if I remember right; braking, plus using the exhaust plume to diminish reentry heating.

The reentry burn deals with getting the vehicle through EI down through the abrupt density increase of the sensible atmosphere. Think of it as "inverse max Q", at supersonic velocity.

Next, how many supersonic craft do you know that have a front fuselage streamlined for flow like the bottom end of a Falcon 9? ;) None. If it hits the atmospheric "air hammer" hard it will decelerate destructively.

So you want retropropulsion to happen before serious thermal/shock damage occurs, then "ride the wake" into transonic regime, then as the engine cuts off, the flow reestablishes around the vehicle following the plume and into the wake.

Quote
My question is, would it, under these circumstances, be possible that SpaceX might decide to use a single-engine but 3x longer reentry burn?

They only use a single engine. The length of the burn is about the time from when you can start the engine before the above mentioned event, to below the transition, so its not necessarily improved by more thrust. It may be more effective if an edge engine(s), however this might create an asymmetry that causes the vehicle to tumble if you don't have enough control authority.

Quote
Would that be of any advantage? (I'm thinking of the usefulness of the plume regarding diminishing the compression heating of reentry).

Something to keep in mind is that the plume may be "cooler" (insulative) then the congested flow or its turbulence. Also, the plume is more stable at supersonic velocity then the flow by far (due to relative velocities).

So the risks of losing 9 seconds of reentry burh:
  * you start too low and the engine does not start at all
  * you start too low, engine starts, but the vehicle's damaged by heat such that it can't be controlled/land
  * you cut off too early and the vehicle sustains shock damage so again it can't land
  * you cut off too early, the plume collapses asymmetrically, the vehicle loses stability into a tumble

I'll be really surprised if the re-entry burn can be shortened, because it normally takes the launcher through transonic speeds or around Mach 1 during the last few seconds, and the grid fins don't operate as effectively if at all when surrounded by the shock waves of transonic speeds, so the fins can't take over the job of the burn to keep the vehicle oriented.

Grid fins work quite well at hypersonic/supersonic speeds. The problem with orientation is more an issue of the stagnation pressure ahead of those nine engines.

Quote
Alternatively, the boostback burn is designed to be modifiable, dependent on fuel availability and target location for each flight. For a barge landing Elon Musk has already tweeted that lateral velocity doesn't need to be zeroed out.

It's entirely downrange - no boostback. The whole point of a non anchored, floating barge. So that you can recover FH core even further downrange.

Quote
It sounds possible that the landing burn can also be modified with the changes in the legs for F9 FT. I think the legs were already designed to contribute to deceleration, and now they can be opened earlier to do so. They are also designed to provide additional aerodynamic stability when deployed, and do not "destabilize" the vehicle as someone suggested earlier.

Nope - it's the one of the three you can least "play" with, the one with the most margin. Best you can get is perhaps a few seconds, where your props margin is also "a few seconds".

Quote
Alternatively, the boostback burn is designed to be modifiable, dependent on fuel availability and target location for each flight.

Or eliminated entirely on a severely constrained mission, which this is. I would expect to see the ASDS quite far downrange, consistent with no boostback burn at all, only a reentry burn.

AIUI, that's the plan for future FH cores, so we might see a recovery profile that's a "trial run" for FH core recoveries.

Yup, its a deep outfielder reaching for the fences. And, if they minimize reusability props for F9, the same techniques used for the FH core return about 1.5x more - it has to stage higher/faster to gather their projected performance claims.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/14/2016 05:16 AM
Where are you getting your information, SpaceGhost? The Falcon 9FT page at http://spaceflight101.com/spacerockets/falcon-9-ft/ seems a reliable source with a lot of details, and they're saying the boostback normally uses a "subset" of engines (after nitrogen thrusters reorient the stage to engines first), and that the re-entry burn uses 3 engines. They also say the grid fins work well at all velocities except for transonic, just as I said, and the fins aren't deployed until the supersonic range at re-entry, around Mach 4, not in the hypersonic region above Mach 5. There is some help from the low center of gravity to keep the engines forward, that's it. No steering w/o grid fins or gimbaled engines running.

You're right there wouldn't be much room to play with the landing burn, only a few seconds, but I didn't mean to imply more than that. It's only about a 13 second burn as far as I can tell from the same reference.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/14/2016 10:55 AM
They only use a single engine.

Then why is there a clear interference pattern developing in the plume shock interaction here?
https://www.youtube.com/watch?v=CQnR5fhCXkQ
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Hauerg on 02/14/2016 11:36 AM
Because 3 ARE used for rrentry. Only landing is single engined.
SG is wrong.
.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rpapo on 02/14/2016 06:44 PM
How about this: In the boostback and reentry burns you aren't trying to zero out the velocity entirely on a specific point, but are rather trying to lose as much velocity as you can, as quickly as you can.  This is particularly true of the boostback burn.  Only in the landing burn do we care about not accelerating too heavily.

That said, if one of the purposes of the reentry burn is to form a bow shock in front of the engines, then it may possible to do that with only one engine firing.  I say "may", because I don't know just how much pressure is required to maintain that bow shock.  That would be a chore for the CFD guys, of which SpaceX has some of the best around.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/14/2016 08:39 PM
Because 3 ARE used for rrentry. Only landing is single engined.
SG is wrong.
.
Observed Cassiopeia with a scope myself and only saw one engine lit.

In the case of fuel economy, one engine is likely the most fuel efficient.

Have not seen all recovery attempts. BTW, how many have you observed in person?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 02/14/2016 08:46 PM
I don't know just how much pressure is required to maintain that bow shock.  That would be a chore for the CFD guys, of which SpaceX has some of the best around.

Sorry, am I missing something? Could there possibly be a supersonic (wrt the nozzle) exhaust flow heading directly into a hypersonic (wrt the same nozzle but in the other direction) atmospheric flow and yet somehow there isn't shock wave?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rpapo on 02/14/2016 09:05 PM
I don't know just how much pressure is required to maintain that bow shock.  That would be a chore for the CFD guys, of which SpaceX has some of the best around.

Sorry, am I missing something? Could there possibly be a supersonic (wrt the nozzle) exhaust flow heading directly into a hypersonic (wrt the same nozzle but in the other direction) atmospheric flow and yet somehow there isn't shock wave?
The question isn't so much whether or not there will be a shock wave, but rather just what are the dimensions of the shock.  The shock needs to be far enough ahead of the rocket so that it does not impinge on the rocket itself, and therefore provides an effective barrier against hypersonic/supersonic friction heating.  The rocket is designed to deal with the radiative heating provided by the rocket exhaust heading out.  Dealing with the friction heating caused by the direct impact of the hypersonic air flow, albeit at very low density, is not exactly what the bottom end of the Falcon rocket was designed for.  Far stronger structures have been damaged irreparably by such air-flows.  Look at what happened to the prototype ramjet design bolted onto the X-15.

Obviously it has worked for SpaceX.  The only question is whether the effect can be sustained sufficiently with only one engine burning.  Separately, we can ask whether the effect can be maintained at a lower throttle setting, and just what is the critical speed range over which it is needed.

SG seems to indicate "yes" (one engine), at least in the very first test: CASSIOPE.  Yet I could have sworn I saw the exhaust pattern of three engines burning in that particular video before the lens sooted up.

NOTE: This might be a trade secret.  Note that SpaceX doesn't show the reentry burn in either of the two CGI preview animations.

EDIT: I correct myself slightly on that last.  Looking at the Falcon Heavy preview animation, the reentry is unclear.  You don't see the business end of the rocket, and it is not at all clear whether the engines are depicted as running at that point.  The glow around the engines is seems to be symmetrical, but it is not obvious the engines are running.

https://www.youtube.com/watch?v=4Ca6x4QbpoM
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: catdlr on 02/14/2016 10:01 PM
So why show an animation where a real video is available?

http://youtu.be/riU3DZmU-jE
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rpapo on 02/14/2016 10:04 PM
So why show an animation where a read video is available?
I knew about that video, but can you tell how many engines are burning here?  I, for one, cannot.  I can't see how you could gather the ingredients of the "secret sauce" from that video.  They probably gave all the relevant parameters to NASA, though.

Mind you, prior to this debate, I took it as a given that three engines were being used for the reentry burn.  Now I wonder.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/15/2016 12:57 AM
Because 3 ARE used for rrentry. Only landing is single engined.
SG is wrong.
.
Observed Cassiopeia with a scope myself and only saw one engine lit.

In the case of fuel economy, one engine is likely the most fuel efficient.

Have not seen all recovery attempts. BTW, how many have you observed in person?

It's OK to be wrong, SG. And even if you saw the CASSIOPE(!) re-entry burn, how clear was your view, and are you sure that the 3 engines could not be lined up behind each other from your point of view? And your scope provided a detailed enough view that you could make out individual engine nozzles?

The Cassiope burn did also show an interesting interference pattern, highly suggestive of a multi-engine burn: (see image) - source, this video: https://www.youtube.com/watch?v=RtDbDMRG3q8
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/15/2016 02:05 AM
Dumb question:
People are so used to thinking about what is required to get out of the atmosphere fast then they might not have much background for what is required here.
Maybe some brainstorming is required to list unlikely variables and there are plenty of people on this site like me with no credibility to lose and can provide the raw material:
If the purpose of the reentry burn is bow shock modification rather than direct  velocity reduction then could other behaviours be at play?
Unfortunately the only variable I can think they have to play with is the fuel mixture (more RP1 less O2) and its interaction with the tenuous hypersonic air and can't see why that would make any difference. Is it possible to pulse fire these engines?
Any other variables possible - ?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/15/2016 03:10 AM
Dumb question:
People are so used to thinking about what is required to get out of the atmosphere fast then they might not have much background for what is required here.
Maybe some brainstorming is required to list unlikely variables and there are plenty of people on this site like me with no credibility to lose and can provide the raw material:
If the purpose of the reentry burn is bow shock modification rather than direct  velocity reduction then could other behaviours be at play?
Unfortunately the only variable I can think they have to play with is the fuel mixture (more RP1 less O2) and its interaction with the tenuous hypersonic air and can't see why that would make any difference. Is it possible to pulse fire these engines?
Any other variables possible - ?

There is research on this sort of retropropulsion. Back on page 31 of this thread I linked to a paper and a video was posted on the topic.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Zach Swena on 02/15/2016 03:22 AM
Looking at the reentry thermal video, it is clear that the reentry burn does start slightly after entry in to the atmosphere as there is clear bow heating and a visible boundary layer around the rocket prior to engine ignition.  It looks like the reentry burn occurs to shorten the max q portion of the flight. 

The burn that seems like easiest to shorten would be the boost back burn.  Even on the previous down range water or barge attempts, I seem to remember there being some amount of boost back burn just to decrease the horizontal velocity.  I don't think they have much leeway for reducing either reentry or landing burns at this point.  Landing burn could shorten when they partially open the legs, but we have no information suggesting that is something they are ready to test yet.  Do we know if they have performed a recovery attempt without a boost back burn yet?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/15/2016 04:50 AM
Dumb question:
People are so used to thinking about what is required to get out of the atmosphere fast then they might not have much background for what is required here.
Maybe some brainstorming is required to list unlikely variables and there are plenty of people on this site like me with no credibility to lose and can provide the raw material:
If the purpose of the reentry burn is bow shock modification rather than direct  velocity reduction then could other behaviours be at play?
Unfortunately the only variable I can think they have to play with is the fuel mixture (more RP1 less O2) and its interaction with the tenuous hypersonic air and can't see why that would make any difference. Is it possible to pulse fire these engines?
Any other variables possible - ?

There is research on this sort of retropropulsion. Back on page 31 of this thread I linked to a paper and a video was posted on the topic.

Yes I know I've been part of this thread and that paper doesn't seem to explain SpaceX behaviour.

OK - as no one else wants to , I'll continue to make a fool of myself: perhaps they are running one engine rp1 rich or dumping rp1 into the plume from the other two just for  for cooling reasons. Maybe this accounts for some of the coking.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 02/15/2016 04:53 AM
OK - as no one else wants to , I'll continue to make a fool of myself

Nah, you're not alone. I'm happy to make a fool of myself too! ;)

My bet is that this time (at least) they will attempt the reentry burn with a single Merlin engine firing, and possibly firing only during the highest Q portion of the reentry.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/15/2016 05:52 AM
Yes I know I've been part of this thread and that paper doesn't seem to explain SpaceX behaviour.

OK - as no one else wants to , I'll continue to make a fool of myself: perhaps they are running one engine rp1 rich or dumping rp1 into the plume from the other two just for  for cooling reasons. Maybe this accounts for some of the coking.

Sorry, I guess I just didn't really understand the motivation of your post. Which SpaceX behaviour are you referring to?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/15/2016 07:52 AM

OK - as no one else wants to , I'll continue to make a fool of myself: perhaps they are running one engine rp1 rich or dumping rp1 into the plume from the other two just for  for cooling reasons. Maybe this accounts for some of the coking.

They aren't
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Poole Amateur on 02/15/2016 09:32 AM
Am loving this speculation, part of what makes this site so great. In 9 days, hopefully we will find out whether the answer is a) No recovery attempt, b) Recovery attempt completely fails with stage break up, c) they miss and warm up the sea or d) They land/arrive on the fair drone ship "Just Read the Dents Instructions"

It's going to be a fun ride and I'm really enjoying all your posts people. Thank you!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: vapour_nudge on 02/15/2016 09:50 AM
I'm disappointed they're going to recover it as I was lead to believe "they" were going to use the first stage for ASAT testing against a recently launched - tumbling- NK satellite.
-  I read it on the Internet  ;)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rasumner on 02/15/2016 10:29 AM
In a mission like this where there is little margin left, what happens to the upper stage after launch? Is it deorbitted or left in orbit? If the latter, how long is it expected to remain in orbit until the orbit decays and it reenters?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hopalong on 02/15/2016 11:10 AM
In a mission like this where there is little margin left, what happens to the upper stage after launch? Is it deorbitted or left in orbit? If the latter, how long is it expected to remain in orbit until the orbit decays and it reenters?

Have a look at this - it should answer your question.

http://www.spacesafetymagazine.com/space-debris/mitigation/compliance-rocket-upper-stage-gto-space-debris-mitigation-guidelines/

The GTO orbit normally has a low perigee, so a very short burn will cause the S2 to reenter, you will need to ensure that it reenters over ocean.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: woods170 on 02/15/2016 01:44 PM

The Cassiope burn did also show an interesting interference pattern, highly suggestive of a multi-engine burn<snip>

It's suggestive, but most definitely not conclusive.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JamesH on 02/15/2016 01:58 PM

The Cassiope burn did also show an interesting interference pattern, highly suggestive of a multi-engine burn<snip>

It's suggestive, but most definitely not conclusive.

I'm always wary of highly compressed video, as that in itself can introduce very odd artifacts, especially in a rapidly changing scene like this. Make sure that has been eliminated as a source of 'interference' patterns.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/15/2016 02:05 PM
Those are definitely not compression artifacts. I'll be as bold as to claim it's not even a readout artifact from the chip i.e. something like the rolling shutter effect with CMOS chips. Given this is interlaced input video, it's virtually certain this is a CCD chip and so it doesn't suffer from such pixel readout timing variations.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: alang on 02/15/2016 02:07 PM

OK - as no one else wants to , I'll continue to make a fool of myself: perhaps they are running one engine rp1 rich or dumping rp1 into the plume from the other two just for  for cooling reasons. Maybe this accounts for some of the coking.

They aren't

:-)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cro-magnon gramps on 02/15/2016 02:48 PM

OK - as no one else wants to , I'll continue to make a fool of myself: perhaps they are running one engine rp1 rich or dumping rp1 into the plume from the other two just for  for cooling reasons. Maybe this accounts for some of the coking.

They aren't

:-)

yup, it's best to just nod our heads, and accept that perhaps he has privileged knowledge we "mere mortals" are unaware of. Leave it up to the other "gods" to argue the point, and stand out of the way of the lightning bolts  ;D at least that has been my experience over the years.

Cheers
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/15/2016 04:19 PM

The Cassiope burn did also show an interesting interference pattern, highly suggestive of a multi-engine burn<snip>

It's suggestive, but most definitely not conclusive.

Do a 2D Fourier transform of the pattern if you don't recognize it. 
(I know. There isn't really data to work with.)
You will get three regularly spaced point sources.
It is quite remarkable and recognizable.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/15/2016 04:36 PM
From the UPDATE thread, jacqmans posted the attached image.

Question: The hazard area only extends out by 63 NM? So any ASDS landing attempt places the barge no farther than 63 NM from the Cape, or is there a second zone farther downrange for the landing attempt?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mvpel on 02/15/2016 05:10 PM
Here's the FCC STA for the launch (F9-22), which doesn't include the ASDS radios:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=68937&RequestTimeout=1000
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/15/2016 05:24 PM
Is it possible that the ASDS recovery zone is so far out to sea that we've entered international waters and left fcc jurisdiction?

The notice to mariners is not US-specific, but the above hazard map looks to be specific to the Cape.  We'll see if there's a more comprehensive hazard warning issued by the coast guard.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jcc on 02/15/2016 08:27 PM
Dumb question:
People are so used to thinking about what is required to get out of the atmosphere fast then they might not have much background for what is required here.
Maybe some brainstorming is required to list unlikely variables and there are plenty of people on this site like me with no credibility to lose and can provide the raw material:
If the purpose of the reentry burn is bow shock modification rather than direct  velocity reduction then could other behaviours be at play?
Unfortunately the only variable I can think they have to play with is the fuel mixture (more RP1 less O2) and its interaction with the tenuous hypersonic air and can't see why that would make any difference. Is it possible to pulse fire these engines?
Any other variables possible - ?

SpaceX has several optimization objectives to fulfill one goal, that is, to get the stage back intact and suitable for reuse with the minimum impact to the mission in terms of reserved fuel and lift capacity.

Optimization objectives include RTLS with minimum fuel for boostback if RTLS, or land down range (objective 1). That takes place above the atmosphere, where the bow shock is not an issue. For reentry, they need to avoid damage due to excessive heating and pressure (objective 2), but they do want to maximize the effect of atmospheric resistance to slow the stage (objective 3), and of course by the end  of the reentry burn the stage must still be decelerating to terminal velocity, not speeding up again due to gravity, so it has to occur in the atmosphere. Here, maximizing the bow shock is  desirable and they probably want to adjust the thrust, timing, and even gimble the engines to do that, without violating objective 2, or constraining objective 1. I don't know how much leeway they have to do so, if the trajectory they need to follow to minimize fuel requires maximum deceleration as soon as it enters the atmosphere, then  they may need to just blast the engines without maximizing the bow shock.

A traditional blunt body reentry vehicle has an ablative TPS and/or heats to thousands of degrees, which is not possible in this case.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/16/2016 07:13 AM
From the UPDATE thread, jacqmans posted the attached image.

Question: The hazard area only extends out by 63 NM? So any ASDS landing attempt places the barge no farther than 63 NM from the Cape, or is there a second zone farther downrange for the landing attempt?

This is only the close inshore safety zone.  There's another one for the potential debris impact areas/1st stage landing area further out.  See the lower inset of the map image.   "CG [Coast Guard] Safety Zone B per 33 CFR 165.775 active 6:01pm to 8:39pm, 24 Feb 16." 


Here's the FCC STA for the launch (F9-22), which doesn't include the ASDS radios:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=68937&RequestTimeout=1000

The FCC authorization for the ASDS segment (recovery/landing) is covered in a separate grant:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/16/2016 10:18 AM

From the UPDATE thread, jacqmans posted the attached image.

Question: The hazard area only extends out by 63 NM? So any ASDS landing attempt places the barge no farther than 63 NM from the Cape, or is there a second zone farther downrange for the landing attempt?

This is only the close inshore safety zone.  There's another one for the potential debris impact areas/1st stage landing area further out.  See the lower inset of the map image.   "CG [Coast Guard] Safety Zone B per 33 CFR 165.775 active 6:01pm to 8:39pm, 24 Feb 16." 


Here's the FCC STA for the launch (F9-22), which doesn't include the ASDS radios:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=68937&RequestTimeout=1000

The FCC authorization for the ASDS segment (recovery/landing) is covered in a separate grant:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000
Yikes! 28 16 10 North, 73 49 5 West is definitely out there! That's like, what, 400 NM due east? (That's a rough guess). Thanks for that link. Now we know right where the barge is going and can calculate departure time.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: chapi on 02/16/2016 12:17 PM

From the UPDATE thread, jacqmans posted the attached image.

Question: The hazard area only extends out by 63 NM? So any ASDS landing attempt places the barge no farther than 63 NM from the Cape, or is there a second zone farther downrange for the landing attempt?

This is only the close inshore safety zone.  There's another one for the potential debris impact areas/1st stage landing area further out.  See the lower inset of the map image.   "CG [Coast Guard] Safety Zone B per 33 CFR 165.775 active 6:01pm to 8:39pm, 24 Feb 16." 


Here's the FCC STA for the launch (F9-22), which doesn't include the ASDS radios:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=68937&RequestTimeout=1000

The FCC authorization for the ASDS segment (recovery/landing) is covered in a separate grant:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000
Yikes! 28 16 10 North, 73 49 5 West is definitely out there! That's like, what, 400 NM due east? (That's a rough guess). Thanks for that link. Now we know right where the barge is going and can calculate departure time.
But this authorization was requested before SES-9 launch postponement, and the subsequent statement that no recovery operation would occur on this launch, no? (to the benefit of the spacecraft in orbit transit time)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/16/2016 12:46 PM
The statement was never that "no recovery attempt would take place".  The statement was that they are attempting a more risky recovery in order to give ses-9 a more advantageous orbit.  Let's not turn into an echo chamber of false information.

Wrt to your main point: assuming this application hasn't been amended and does in fact predate the SES press release, possible interpretations:
1. The new launch plan was in the works for some time, and got announced only after it was "final".
1b. Ditto, but the announcement was primarily timed for SES's investors (dont they have a quarterly earnings call coming up?).
2. The plan all along was for no boostback burn, but the SES announcement/new plan was to shorten the reentry burn as well (this has been debated at length here on NSF).

Other thoughts on ways to reconcile the timing... assuming there's anything here to reconcile?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Exastro on 02/16/2016 01:05 PM
Those are definitely not compression artifacts. I'll be as bold as to claim it's not even a readout artifact from the chip i.e. something like the rolling shutter effect with CMOS chips. Given this is interlaced input video, it's virtually certain this is a CCD chip and so it doesn't suffer from such pixel readout timing variations.

Agreed that it doesn't look like a compression artifact, but I think you have CCD and CMOS reversed here.  A lot of CMOS arrays can be read out in a 'global shutter' mode that avoids the rolling-shutter effect.  CCDs are notorious for it.

NB: For those not intimate with these things, the rolling-shutter effect is caused by imaging arrays that expose pixels sequentially rather than simultaneously.  If something is moving at a speed which is comparable to the rate at which the exposure sweeps across the array, it can be severely distorted (stretched or shrunken in the readout direction). 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/16/2016 01:14 PM
The statement was never that "no recovery attempt would take place".  The statement was that they are attempting a more risky recovery in order to give ses-9 a more advantageous orbit.  Let's not turn into an echo chamber of false information.

Wrt to your main point: assuming this application hasn't been amended and does in fact predate the SES press release, possible interpretations:
1. The new launch plan was in the works for some time, and got announced only after it was "final".
1b. Ditto, but the announcement was primarily timed for SES's investors (dont they have a quarterly earnings call coming up?).
2. The plan all along was for no boostback burn, but the SES announcement/new plan was to shorten the reentry burn as well (this has been debated at length here on NSF).

Other thoughts on ways to reconcile the timing... assuming there's anything here to reconcile?

Another thing I don't quite understand: a couple of pre- FT hazard areas had centers around 500 mile downrange, so I was expecting the FT upgrade with its higher staging velocity to have a landing zone even farther out (assuming no boostback burn).

Maybe the seeming discrepancy is because the re-entry burn will reduce some/most of the horizontal velocity component, in effect truncating the tail of the ballistic arc.

Also, the ASDS may be positioned farther out than the permit states, due to the later decision to give the payload more delta V from the first stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hkultala on 02/16/2016 01:18 PM
The statement was never that "no recovery attempt would take place".  The statement was that they are attempting a more risky recovery in order to give ses-9 a more advantageous orbit.  Let's not turn into an echo chamber of false information.

Wrt to your main point: assuming this application hasn't been amended and does in fact predate the SES press release, possible interpretations:
1. The new launch plan was in the works for some time, and got announced only after it was "final".
1b. Ditto, but the announcement was primarily timed for SES's investors (dont they have a quarterly earnings call coming up?).
2. The plan all along was for no boostback burn, but the SES announcement/new plan was to shorten the reentry burn as well (this has been debated at length here on NSF).

Other thoughts on ways to reconcile the timing... assuming there's anything here to reconcile?

Another thing I don't quite understand: a couple of pre- FT hazard areas had centers around 500 mile downrange, so I was expecting the FT upgrade with its higher staging velocity to have a landing zone even farther out (assuming no boostback burn).

If both are used for up to full capasity, FT version has lower staging velocity than 1.1 version; Stage 1 tank size did not increase so all the propellant increase is due subcooling, but stage2 tank was extended. This means stage 2 is doing greater part of the total work, and means lower staging velocity.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/16/2016 01:23 PM
Quote
FT version has lower staging velocity than 1.1 version;

Are you sure about that? I thought I remembered Elon saying staging velocity would be higher.

Quote
This means stage 2 is doing greater part of the total work, and means lower staging velocity.

That assumes that the "total work" of the previous model and the FT model are the same, but they're not. The FT model imparts more total delta V to a given payload, so S1 staging velocity can be higher even though the S1/S2 energy ratio shifts slightly in favor of S2.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/16/2016 01:44 PM
Agreed that it doesn't look like a compression artifact, but I think you have CCD and CMOS reversed here.

I don't think I have. CCDs integrate over the entire chip at once and if the exposure duration is >> than the time it takes to readout/store into another buffer, the only side-effect is a ghostly readout smear, oriented vertically or horizontally, depending on how the frame is transferred. CCDs are not susceptible to a rolling shutter as a result, however they are more expensive and are more susceptible to charge bleed artifacts.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/16/2016 02:05 PM
The 500nm hazard areas might have been the fairing drop zones in previous attempts?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/16/2016 04:47 PM
Stage 1 tank size did not increase so all the propellant increase is due subcooling, but stage2 tank was extended. This means stage 2 is doing greater part of the total work, and means lower staging velocity.

It wasn't as apparent that tank sizes in stage 1 were altered for FT, because stage 1 couldn't be stretched like the 2nd stage could, and because the total tank volume didn't change. Bending forces in flight impose a limit on length, and the stage 1 length was maxed out with the stretch from v1.0 to v1.1. The diameter of either stage couldn't be increased either, due to road transport restrictions. The Merlin 1D engines run fuel-rich, but kerosene can't be cooled & densified as much as LOX can, so to accommodate, the stage 1 LOX tank was shortened and the RP-1 tank was stretched into the extra space. Stage 2 altogether was only stretched by about half a meter, but apparently that was enough to accommodate a sufficient stretch of its own RP-1 tank (I don't know if there was any shortening of the stage 2 LOX tank).

It is true that FT changes to stage 2 were so that stage 2 could do more work with less reliance on stage 1, but as Kabloona pointed out, stage 1 performance was also increased for an improved total.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: JamesH on 02/16/2016 04:53 PM
Agreed that it doesn't look like a compression artifact, but I think you have CCD and CMOS reversed here.

I don't think I have. CCDs integrate over the entire chip at once and if the exposure duration is >> than the time it takes to readout/store into another buffer, the only side-effect is a ghostly readout smear, oriented vertically or horizontally, depending on how the frame is transferred. CCDs are not susceptible to a rolling shutter as a result, however they are more expensive and are more susceptible to charge bleed artifacts.

Once you get to the silicon, CMOS uses CCD's. The CMOS bit provides readout silicon, which isn't present on CCD's, which need a separate system. The way the readout is done will affect things like the rolling shutter as described.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lee Jay on 02/16/2016 07:10 PM
Agreed that it doesn't look like a compression artifact, but I think you have CCD and CMOS reversed here.

I don't think I have. CCDs integrate over the entire chip at once and if the exposure duration is >> than the time it takes to readout/store into another buffer, the only side-effect is a ghostly readout smear, oriented vertically or horizontally, depending on how the frame is transferred. CCDs are not susceptible to a rolling shutter as a result, however they are more expensive and are more susceptible to charge bleed artifacts.

Once you get to the silicon, CMOS uses CCD's. The CMOS bit provides readout silicon, which isn't present on CCD's, which need a separate system. The way the readout is done will affect things like the rolling shutter as described.

CCD is the readout method, not the detection method.  CCDs shuffle the charge to the edge for A-to-D, while CMOS reads them in-place.

Perhaps you meant to say once you get to the silicon, CMOS and CCDs both use photodiodes.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/16/2016 07:30 PM
CCD is the readout method, not the detection method.  CCDs shuffle the charge to the edge for A-to-D, while CMOS reads them in-place. Perhaps you meant to say once you get to the silicon, CMOS and CCDs both use photodiodes.

I have an answer to the original question, for those who still remember it :). Directly from the SpaceX news page on the Sept 2013 CASSIOPE mission at http://www.spacex.com/news/2013/10/14/upgraded-falcon-9-mission-overview, there were two relights of the 1st stage after de-staging -- one for re-entry which used three engines, and a landing-on-the-ocean burn w/o landing gear which used one engine (probably the one SpaceGhost saw). Although at the time those mission add-ons were believed to complete the SpaceX knowledge base for trying the real thing, the relevance to a complete landing profile for the SES-9 mission is limited.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/16/2016 07:49 PM
The FCC authorization for the ASDS segment (recovery/landing) is covered in a separate grant:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000

Yikes! 28 16 10 North, 73 49 5 West is definitely out there! That's like, what, 400 NM due east? (That's a rough guess). Thanks for that link. Now we know right where the barge is going and can calculate departure time.

If those coordinates are ~400NM out, why do the [radio] Station Location headings say the boat and the barge are w/in 10NM?

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app or a website that can?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/16/2016 07:50 PM

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app that can?

 That is S-Band and not a typical scanner frequency.  And also, it would not be voice.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/16/2016 08:16 PM

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app that can?

 That is S-Band and not a typical scanner frequency.  And also, it would not be voice.

Well Jim, then would you mind deciphering and relaying the information on NSF as it comes in?

Just kidding.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Johnnyhinbos on 02/16/2016 08:30 PM
If those coordinates are ~400NM out, why do the [radio] Station Location headings say the boat and the barge are w/in 10NM?

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app or a website that can?
I believe that is to signify that the boat (Go Quest) and barge (OCISLY) are within 10 NM of the coordinates provided. I don't know if these coordinates denote the exact ASDS location (perhaps not for security reasons?) but within 10 NM of the coordinates, and then Go Quest at some safe stand-off distance from the ASDS.

As to the provided radio frequency Jim already answered it, but to add, 2.09 GHz is in the realm of ultra high frequency and is data. VHF is an order of magnitude lower in frequency (and even lower) and is (primarily) used for voice as it has a much lower data rate. But regardless, the FCC application is for data, and can only be received within a radius of 18.52 NM of transmitter.

Man, I can't wait for next Wednesday!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kevin-rf on 02/16/2016 08:34 PM
Agreed that it doesn't look like a compression artifact, but I think you have CCD and CMOS reversed here.

I don't think I have. CCDs integrate over the entire chip at once and if the exposure duration is >> than the time it takes to readout/store into another buffer, the only side-effect is a ghostly readout smear, oriented vertically or horizontally, depending on how the frame is transferred. CCDs are not susceptible to a rolling shutter as a result, however they are more expensive and are more susceptible to charge bleed artifacts.

Once you get to the silicon, CMOS uses CCD's. The CMOS bit provides readout silicon, which isn't present on CCD's, which need a separate system. The way the readout is done will affect things like the rolling shutter as described.

CCD is the readout method, not the detection method.  CCDs shuffle the charge to the edge for A-to-D, while CMOS reads them in-place.

Perhaps you meant to say once you get to the silicon, CMOS and CCDs both use photodiodes.

It also depends on what kind of CCD is used.

Classic CCD, where the charge transfer rate is based on the speed of the AtoD which without a shutter or pulsed light source leads to significant charge smear while it waits to be read out. This is why you don't see these very often in cameras that provide video.

Frame transfer, where the entire charge is quickly transferred to the side under a mask and then read out. Greatly reduced smearing, commonly coupled with EM CCD technology. Often see these in low light (security) cameras, very little woble, just a faint smear which is a function of how fast the charge is transferred across the sensor verses the exposure time.

Interline, think of a picket fence, every other row is a mask. Charge is transferred sideways one pixel and then slowly read out. It is a Global Shutter. It is close as you can get to a real shutter (unless you go with an ICCD). It is what is mostly used in CCD video cameras. Sony makes a large amount of money selling Interline CCD's. They are the king. Disadvantage is you don't have 100% fill factor on the pixels, but hey, add in a Bayer filter, and other compromises... Still the best CCD option.

This doesn't included multi-tap CCD' which use multiple taps to feed multiple AtoD's from the CCD. 2 Tap, left right side of the sensor to separate AtoD's, 4 tap, the four corners, ect.... But they are expensive and have intensity balance issues. Usually only found on very specialized projects. In 20 years I've only worked with one.

CMOS on the other hand does not move the charge around, reading the charge out in place. Rolling Shutter. Hence being able to get a jello like shimmer in the video...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/16/2016 09:04 PM

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app that can?

 That is S-Band and not a typical scanner frequency.  And also, it would not be voice.

Well Jim, then would you mind deciphering and relaying the information on NSF as it comes in?

Just kidding.

Veering into party thread turf. besides we all know Jim doesn't need to decypher it, the experienced steely eyed missile man understands the cyphered version.

More seriously, is there any reason to believe any of this data is likely to be available to the general public? I am thinking not, if only due to the location.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/16/2016 10:07 PM
The FCC authorization for the ASDS segment (recovery/landing) is covered in a separate grant:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=69076&RequestTimeout=1000

Yikes! 28 16 10 North, 73 49 5 West is definitely out there! That's like, what, 400 NM due east? (That's a rough guess). Thanks for that link. Now we know right where the barge is going and can calculate departure time.

If those coordinates are ~400NM out, why do the [radio] Station Location headings say the boat and the barge are w/in 10NM?

Also, Johnny, can the radio scanning app you gave us for ORBCOMM ASDS & support tracking get us onto the 2090.00000000-MHz radio frequency, or do you or anyone know of an app or a website that can?

Just as a note, that original STA grant for the Boat/Barge duo was issued (on Jan. 15th) well before the changes to the flight plan.  So, depending on exactly how those changes are modeled to play out, it is likely to be updated/changed.  Basically, don't take the coordinates listed in that STA grant as gospel.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sdsds on 02/17/2016 07:55 AM
One clue to recovery trajectory will be how many days before launch the ASDS leaves port. Farther downrange recovery means the armada has to head out sooner. My guess is 5-7 days prior, which could be as early as a Wednesday 17th departure for a launch on the 24th.

So with the armada still in port and the intended ASDS location something like 662 km downrange are they now "no go" for recovery if the launch were on the 24th?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rower2000 on 02/17/2016 09:20 AM
One clue to recovery trajectory will be how many days before launch the ASDS leaves port. Farther downrange recovery means the armada has to head out sooner. My guess is 5-7 days prior, which could be as early as a Wednesday 17th departure for a launch on the 24th.

So with the armada still in port and the intended ASDS location something like 662 km downrange are they now "no go" for recovery if the launch were on the 24th?
I wouldn't say so. At 5 kn towing speed which should be reasonable, the barge could make the 660 km (360 nm) in about three days.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/17/2016 11:18 AM
Expect the barge to leave port around the time of the static fire.

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1492179.msg#1492179
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/17/2016 05:42 PM
F9-022 SES-9 Hazard areas
https://goo.gl/VQKBXz

SES-9 barge position 662km downrange
FCC APPLICATION: https://goo.gl/up13ae

At 662 km downrange, the flight path will be visible from sea level at the launch site (and most of the observing locations) until the first stage drops below 34. km altitude.

How does that compare to the assumed altitudes of the braking burn?

A 15 second braking burn (very rough approximation) running 2g's (10 m/sec^2 net deceleration) would start just over 1 km, so it will be well below the horizon.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/17/2016 06:19 PM
Quote
A 15 second braking burn (very rough approximation) running 2g's (10 m/sec^2 net deceleration) would start just over 1 km, so it will be well below the horizon.

That's the landing burn. The question was about the reentry braking burn, which will be at much higher altitude.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lars-J on 02/17/2016 09:55 PM

Quote
A 15 second braking burn (very rough approximation) running 2g's (10 m/sec^2 net deceleration) would start just over 1 km, so it will be well below the horizon.

That's the landing burn. The question was about the reentry braking burn, which will be at much higher altitude.

Braking burns so far have been done from ~70km down to ~40km, but this one might be different.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/18/2016 02:44 AM
I think that this terminology of "braking burn" is confusitory.  You don't know whether its being applied to the boostback burn, re-entry burn, or (probably less so) the landing burn.

Q: How was the ASDS video sent back on the last launch?  Was it only possible with the southward flight path that had the ASDS relatively close to shore or through satellite which would not tend to suffer with the far offshore ASDS position we've got coming up?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/18/2016 02:50 AM
Quote
Q: How was the ASDS video sent back on the last launch?  Was it only possible with the southward flight path that had the ASDS relatively close to shore or through satellite which would not tend to suffer with the far offshore ASDS position we've got coming up?

I would guess through the VSAT domes visible atop the containers, ie via satellite.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: georgegassaway on 02/18/2016 03:25 AM
I think that this terminology of "braking burn" is confusitory.  You don't know whether its being applied to the boostback burn, re-entry burn, or (probably less so) the landing burn.

I agree. It is less confusing to say boostback burn, re-entry (or entry) burn, or landing burn, when referring specifically to one of those. Than to try to shoehorn the word "braking" to mean only one of those. 

For example the top hit when I googled "Falcon 9 braking" was a story from a year ago calling all three burns "braking burns" (Which each burn indeed is, even if the boostback burn later goes from braking to acceleration once downrange velocity has been negated). Then it refers to each individual burn as boostback, entry , and landing burns. No confusion.

http://spaceflightnow.com/2015/02/07/new-challenges-await-spacexs-next-rocket-landing-attempt/

- George Gassaway
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 02/18/2016 03:43 AM
maybe we should call the boostback "burn 1.0", reentry "burn 1.1", and landing "burn 1.1 FT"
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/18/2016 04:11 AM

F9-022 SES-9 Hazard areas
https://goo.gl/VQKBXz (https://goo.gl/VQKBXz)

SES-9 barge position 662km downrange
FCC APPLICATION: https://goo.gl/up13ae (https://goo.gl/up13ae)

At 662 km downrange, the flight path will be visible from sea level at the launch site (and most of the observing locations) until the first stage drops below 34. km altitude.

How does that compare to the assumed altitudes of the braking burn?

A 15 second braking burn (very rough approximation) running 2g's (10 m/sec^2 net deceleration) would start just over 1 km, so it will be well below the horizon.

Braking burns so far have been done from ~70km down to ~40km, but this one might be different.

With all due respect, it is clear that it could be different, but if it doesn't go longer and lower, which is not a change we would expect, than the whole braking / re-entry burn should be visible through an adequate optic. 

Images are easily saturated when the plume extends across multiple pixels, so it should be visible if the plume width is between 10% and 1% of a pixel.  At 668 km a 3.3 meter wide plume (guess) would subtend 1/2E5 or 5E-6 = 5 uRad = 1 arc-sec.  A pixel 100 times bigger would be 100 arc sec = 1.6 arc-min ~ 1/20 of the moon.  We can do that with a cell phone camera, so a good camera should be able to record the braking/reentry burn.  (Ignoring issues of aperture and atmospheric loss through the long path.)   
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: baldusi on 02/18/2016 02:46 PM
I think that this terminology of "braking burn" is confusitory.  You don't know whether its being applied to the boostback burn, re-entry burn, or (probably less so) the landing burn.

Q: How was the ASDS video sent back on the last launch?  Was it only possible with the southward flight path that had the ASDS relatively close to shore or through satellite which would not tend to suffer with the far offshore ASDS position we've got coming up?
BTW, "braking burn" is technically called a retro-burn, i.e. against(ish) your velocity vector. In the timeline they would be Ignition 2, Ignition 3 and Ignition 4. So boostback, re-entry and landing would be the most unambiguous terms.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lee Jay on 02/18/2016 03:03 PM

F9-022 SES-9 Hazard areas
https://goo.gl/VQKBXz (https://goo.gl/VQKBXz)

SES-9 barge position 662km downrange
FCC APPLICATION: https://goo.gl/up13ae (https://goo.gl/up13ae)

At 662 km downrange, the flight path will be visible from sea level at the launch site (and most of the observing locations) until the first stage drops below 34. km altitude.

How does that compare to the assumed altitudes of the braking burn?

A 15 second braking burn (very rough approximation) running 2g's (10 m/sec^2 net deceleration) would start just over 1 km, so it will be well below the horizon.

Braking burns so far have been done from ~70km down to ~40km, but this one might be different.

With all due respect, it is clear that it could be different, but if it doesn't go longer and lower, which is not a change we would expect, than the whole braking / re-entry burn should be visible through an adequate optic.

If the atmosphere were transparent, that would be true.  But atmospheric distortion through 600+km of dense air near the horizon is extreme, to say the least.  I have trouble with 1km of dense atmosphere, and 10km of dense atmosphere is like looking through a frosted window.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kch on 02/18/2016 03:20 PM
maybe we should call the boostback "burn 1.0", reentry "burn 1.1", and landing "burn 1.1 FT"

Yes, maybe you should.  ;D
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CyndyC on 02/18/2016 03:26 PM
I think that this terminology of "braking burn" is confusitory.

And good one OxCartMark hahaha. Above all, "confusitory" should be used from here on out to describe and offer partial redemption for ANY ambiguous terminology or statements.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/18/2016 03:59 PM
I think that this terminology of "braking burn" is confusitory.  You don't know whether its being applied to the boostback burn, re-entry burn, or (probably less so) the landing burn.

Q: How was the ASDS video sent back on the last launch?  Was it only possible with the southward flight path that had the ASDS relatively close to shore or through satellite which would not tend to suffer with the far offshore ASDS position we've got coming up?
BTW, "braking burn" is technically called a retro-burn, i.e. against(ish) your velocity vector. In the timeline they would be Ignition 2, Ignition 3 and Ignition 4. So boostback, re-entry and landing would be the most unambiguous terms.

Have you read the play, or seen the movie, "Rhinoceros"?
This discussion is reminiscent of the Ionesco's "philosopher" characters.
Braking, reentry, retro, burn 1.2, ....  there is no real confusion, just a gnashing of teeth.
Can we give it a rest and get back to things like whether that burn, whatever you call it, will be visible through hundreds of kilometers of atmosphere?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CraigLieb on 02/18/2016 05:33 PM
new landing poll up: (not bingo). Good luck.
http://forum.nasaspaceflight.com/index.php?topic=39614.0
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/18/2016 07:22 PM
Our History Center will be closed this Saturday, February 20th. We will be closed again on Tuesday the 23rd & Wednesday the 24th (for the SpaceX SES-9 mission launch). This is subject to change with changes to the launch schedule.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/19/2016 04:07 PM
I think that this terminology of "braking burn" is confusitory.  You don't know whether its being applied to the boostback burn, re-entry burn, or (probably less so) the landing burn.

Q: How was the ASDS video sent back on the last launch?  Was it only possible with the southward flight path that had the ASDS relatively close to shore or through satellite which would not tend to suffer with the far offshore ASDS position we've got coming up?
BTW, "braking burn" is technically called a retro-burn, i.e. against(ish) your velocity vector. In the timeline they would be Ignition 2, Ignition 3 and Ignition 4. So boostback, re-entry and landing would be the most unambiguous terms.

Have you read the play, or seen the movie, "Rhinoceros"?
This discussion is reminiscent of the Ionesco's "philosopher" characters.
Braking, reentry, retro, burn 1.2, ....  there is no real confusion, just a gnashing of teeth.
Can we give it a rest and get back to things like whether that burn, whatever you call it, will be visible through hundreds of kilometers of atmosphere?

Great, yea, lets do that.  So which burn is it that you want to discuss?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/19/2016 05:04 PM
I think the general question is: what burn(s) can we see from shore?  What is this launch going to look like?  I'd there any chance to shoot one of those cute SpaceX crossing-X trails with a long exposure, or will the "coming back" burns all be too far/too high/under the horizon?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/19/2016 05:05 PM
I got confusitoried for a minute, I thought this was the party thread.  Oh ya, it's not.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/19/2016 06:54 PM
From the update thread: SF planned for Saturday.  So, 4 days between static fire and launch.  Will the payload will be on the rocket during the SF?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ZachS09 on 02/19/2016 07:06 PM
From the update thread: SF planned for Saturday.  So, 4 days between static fire and launch.  Will the payload will be on the rocket during the SF?

I believe so.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 02/19/2016 10:09 PM
I think the general question is: what burn(s) can we see from shore?  What is this launch going to look like?  I'd there any chance to shoot one of those cute SpaceX crossing-X trails with a long exposure, or will the "coming back" burns all be too far/too high/under the horizon?

Yeah -- I believe the answer is that there will be no "coming back" burns, no boostback, no crossing trails.  Someone at the Cape might see the entry burn, but it will be at a slant angle of about 400 km or so; if the air is very clear, no intervening cloud decks, etc., then yes, you might see a small spark of light that could even be a tad brighter than the receding stage 2.  Considering the launch will be in the late afternoon/early evening, if we get clear skies, you might see a little bit more than that.

You won't see anything of the landing burn, as it will happen some 600 km downrange and way, way below the horizon from an observer at the Cape.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/19/2016 10:51 PM
I think the general question is: what burn(s) can we see from shore?  What is this launch going to look like?  I'd there any chance to shoot one of those cute SpaceX crossing-X trails with a long exposure, or will the "coming back" burns all be too far/too high/under the horizon?
Yeah -- I believe the answer is that there will be no "coming back" burns, no boostback, no crossing trails.  Someone at the Cape might see the entry burn, but it will be at a slant angle of about 400 km or so; if the air is very clear, no intervening cloud decks, etc., then yes, you might see a small spark of light that could even be a tad brighter than the receding stage 2.  Considering the launch will be in the late afternoon/early evening, if we get clear skies, you might see a little bit more than that.

You won't see anything of the landing burn, as it will happen some 600 km downrange and way, way below the horizon from an observer at the Cape.

45th Wx Sqdrn's weekly planning forecast (official launch forecast not yet published) is calling for partly cloudy with 30% chance of precip. on launch day (02-24) during the PM.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Joaosg on 02/20/2016 12:59 AM
OCISLY left port.

(http://i.imgur.com/qi6qDrT.png)

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1493515#msg1493515
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/20/2016 08:57 PM
From the UPDATES Thread
Updated status: Static Fire aiming for Monday. Launch Wednesday.

That's only two days from static fire to launch.
Using the SpaceX Scrubs Thread (http://forum.nasaspaceflight.com/index.php?topic=36507.msg1311378#msg1311378) as the reference, the historical record of that interval is:

Falcon 9 Flight Number      1   2   3   4   5    6   7   8   9  10  11  12  13  14  15  16  17  18  19  20
Stat Fire to Launch Days  83   4   ?    8   5  10   7   8  10   3   6  15    4  22   11   6    3    5    2   3

Although the trend is down, and many of the delays were for weather or other issues not related to the rocket, the  two day interval has only been achieved once.  It seems unlikely that the SES-9 launch will be on Wednesday.

edit: added interval for Falcon 9 Flight 1
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rockets4life97 on 02/20/2016 10:10 PM
The 2 day interval was the only other F9 FT. So, maybe hard to know from an observation of 1.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/20/2016 10:52 PM
Falcon 9 Flight Number      1   2   3   4   5    6   7   8   9  10  11  12  13  14  15  16  17  18  19  20
Stat Fire to Launch Days  83   4   ?    8   5  10   7   8  10   3   6  15    4  22   11   6    3    5    2   3

Although the trend is down, and many of the delays were for weather or other issues not related to the rocket, the  two day interval has only been achieved once.  It seems unlikely that the SES-9 launch will be on Wednesday.
There have been a few 3 day gaps though.  CRS-6, which had 1 additional day delay between SF and eventual launch due to a weather scrub (i.e. without Wx scrub, could have been 2 day gaps).  And both Orbcomm launches (though I'm not sure we should really count that first one because it was technically the 2nd SF for that launch campaign).   CRS-4 ended up with a 4 day gap but also had its original launch attempt scrubbed for weather on day 2 (i.e. Wx scrub resulted in 2 additional days). So, it's certainly still within the realm of possible given good conditions.

The 2 day interval was the only other F9 FT. So, maybe hard to know from an observation of 1.

No, it was from CRS-7.  The F9 FT launch in Dec. had a 3 day gap, but that was after delaying launch a day post SF to "allow for improved odds for landing and better analysis."  So, assuming the delay was only for the stated reasons, it could have been 2 days.

edit: Just wanted to add a renewed BRAVO! to @cartman for that Scrubs Thread.  It is great.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Wolfram66 on 02/22/2016 02:37 PM
GO Searcher has left Port Canaveral and is on course to rendezvous with GO Quest and OCISLY. Anyone have visual of any additional stands, jacks or equipment on deck when she left port?

thanks
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Alastor on 02/22/2016 03:00 PM
Great article by Chris about the static fire to be and some perspective :
http://www.nasaspaceflight.com/2016/02/spacex-falcon-9-static-fire-ahead-ses-9-launch/ (http://www.nasaspaceflight.com/2016/02/spacex-falcon-9-static-fire-ahead-ses-9-launch/)

Does the FSS include the envisioned system for the astronauts to get into the dragon or is it missing on the pictures ?
Do we even know what they plan on that front ?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/22/2016 08:31 PM
From the UPDATES thread:
Quote
#SpaceX ,#Falcon9 #ses9 upright on pad 40 now. Launch Wednesday 6:47PM Eastern.
https://twitter.com/USLaunchReport

No venting is visible in the image.
What is the usual interval between the start of pumping LOX and ignition?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/22/2016 08:38 PM
From the UPDATES thread:
Quote
#SpaceX ,#Falcon9 #ses9 upright on pad 40 now. Launch Wednesday 6:47PM Eastern.
https://twitter.com/USLaunchReport

No venting is visible in the image.
What is the usual interval between the start of pumping LOX and ignition?

I thought in the Orbcomm2 broadcast they mentioned loading at 30 minutes (instead of hours before) with the colder propellants.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/22/2016 08:46 PM
From the UPDATES thread:
Quote
#SpaceX ,#Falcon9 #ses9 upright on pad 40 now. Launch Wednesday 6:47PM Eastern.
https://twitter.com/USLaunchReport

No venting is visible in the image.
What is the usual interval between the start of pumping LOX and ignition?

I thought in the Orbcomm2 broadcast they mentioned loading at 30 minutes (instead of hours before) with the colder propellants.

Isn't 30 minutes the time from the end of loading to ignition?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/22/2016 08:53 PM
Quote
Isn't 30 minutes the time from the end of loading to ignition?

No. On that launch, LOX loading began around T-35 minutes and ended a few minutes before T-0.

Don't want the subcooled LOX sitting and warming up.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/22/2016 08:53 PM
Yeah, it's a much shorter loading to firing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/22/2016 09:32 PM
Another from the UPDATES thread:
Better one:
Quote
Getting ready...two days! @AFSpace @usairforce @SpaceX #ses9
https://twitter.com/45thSpaceWing

Legs and grid fins are seen.
That puts to rest some speculation.
Still no visible venting

Edit: And now Chris B reports that the engines have fired.  No official word yet, but it looks like venting is too brief to use as a reliable warning.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mme on 02/22/2016 10:27 PM
...

Edit: And now Chris B reports that the engines have fired.  No official word yet, but it looks like venting is too brief to use as a reliable warning.
These new fangled F9 FTs do seem to spend a lot less time sitting around full of propellent.  :)

Admittedly our sample set is minuscule at the moment.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Skyrocket on 02/22/2016 10:42 PM
Small nitpicking on the static fire article (http://www.nasaspaceflight.com/2016/02/spacex-falcon-9-static-fire-ahead-ses-9-launch/): the satellite image shows an Orbital Star-2 type, while SES-9 is a larger Boeing BSS-702. SES-9 illustration in the attachment.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/22/2016 10:49 PM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/22/2016 11:28 PM
Small nitpicking on the static fire article (http://www.nasaspaceflight.com/2016/02/spacex-falcon-9-static-fire-ahead-ses-9-launch/): the satellite image shows an Orbital Star-2 type, while SES-9 is a larger Boeing BSS-702. SES-9 illustration in the attachment.

Stupid google ;) Thanks...sorted now.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: darkenfast on 02/23/2016 04:08 AM
Look at the railroad bogie farthest from the camera.  There appears to be some flame over there (although it might be a camera illusion and really is on the back of the Strongback.).  Did something go flying from the pad?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: docmordrid on 02/23/2016 04:34 AM
Streams

The YouTube "Technical" stream has no talking heads.

SpaceX YouTube (Full webcast): http://youtu.be/Ml1RO4IcOG0

SpaceX YouTube (Technical): http://youtu.be/6HSb_yBnJXA

Livestream prime: http://livestream.com/spacex/events/4862005 (http://"http://livestream.com/spacex/events/4862005")

SpaceX site (Livestream mirror): http://www.spacex.com/webcast (http://"http://www.spacex.com/webcast")
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: okan170 on 02/23/2016 04:52 AM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Swoopert on 02/23/2016 06:17 AM
Look at the railroad bogie farthest from the camera.  There appears to be some flame over there (although it might be a camera illusion and really is on the back of the Strongback.).  Did something go flying from the pad?

Would that not just be a reflection of the glare from the flame of the rocket engines? Some part of that bogie that is angled up and in towards the camera? Although looking again, I think it might well be a part of the strongback mechanism...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Katana on 02/23/2016 06:17 AM
...Ditto if they went above some threshold temperature...
Right, and what are the odds that the temperature is SO even that it doesn't cause local hotpots to exceed total failure but does bring large swaths of the structure past flyability? I find that very unlikely.

It's like a light bulb. It either survives or it doesn't. You're really unlikely to get an in-between (besides minor failures that could be repaired).
Al -Li  alloys are suspectible to loss of thermal treatment and strength.

Landing needs no reliability margins, but reuse it for expensive customer payload needs calculable margins. Even  to calculate the insurance cost versus payload value.

Insufficient material  strength and neglect  of  insurance caused big  problem in the last explosion of NASA payload.

Local hotspots make things  WORSE:  maybe you need to cut airframe into bits to determine the minimal strength.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: deruch on 02/23/2016 02:21 PM
Streams

The YouTube "Technical" stream has no talking heads.

SpaceX YouTube (Full webcast):

SpaceX YouTube (Technical):

Livestream prime: http://livestream.com/spacex/events/4862005 (http://"http://livestream.com/spacex/events/4862005")

SpaceX site (Livestream mirror): http://www.spacex.com/webcast (http://"http://www.spacex.com/webcast")

Comment from redditor /u/bencredible who is in charge of the SpaceX streams:

"I have added the two YouTube live streams now. We're trying the new 'Low Latency' mode on the YouTube side. This cuts the YouTube latency down from ~60 seconds to ~15 seconds (not including any encode/decode or Internet latency). Not sure how well it will work so appreciate constructive feedback. Will continue with the Livestream.com encode as well for our primary stream."
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mattshup on 02/23/2016 03:45 PM
Is the ASDS landing attempt going to be live streamed? Or will it be too far out to sea?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: kona314 on 02/23/2016 03:52 PM
/u/Bencredible said on reddit that they're going to try, but we may lose coverage again as the approach vibrates the satellite uplink. So that also explains why we lost it last time.

I'd link but reddit is blocked here, sorry.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mattshup on 02/23/2016 03:53 PM
Sounds like SpaceX may have to rubber mount the Satelite Uplink or something.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: acsawdey on 02/23/2016 04:04 PM
Sounds like SpaceX may have to rubber mount the Satelite Uplink or something.

That isn't necessarily going to help if the problem is acoustical. What's the sound pressure level of a M1D at a distance of 150-200 feet and looking up towards the bell? That's about when the sat link gave out on the Jason-3 landing. We saw the reflected light so it was maybe 50-100' up, and the sat link can't be more than about 150' from the center of the barge.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/23/2016 04:08 PM
Seems like you could put an omni antenna on the barge and a bent pipe sat link on the support ship. I admit im no RF expert but it shouldn't be hard. Perhaps it's just not worth the effort for them though.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Navier–Stokes on 02/23/2016 05:31 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: tleski on 02/23/2016 06:09 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.

At the same time James Dean tweets the following:

"SES has clarified that profile adjustment made to upcoming launch had no bearing on F9 booster recovery; only impacts upper stage burn."
https://twitter.com/flatoday_jdean/status/702182942458642432

A little confusing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jarnis on 02/23/2016 06:11 PM
I guess this is all just an exercise in trying to downplay the expectations of the peanut gallery watching. It is a challenging profile to catch the stage back from a GTO launch no matter what.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ohsin on 02/23/2016 06:16 PM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/23/2016 06:29 PM
Wiring for heaters to keep the leg locks dry?

Matthew
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Joffan on 02/23/2016 06:44 PM
Over from the updates thread, I just wanted to observe from the static firing that this pad does a great job of directing all the smoke/flame sideways (which seemed to catch the camera operator off-guard), leaving the vehicle visible throughout. That has to be regarded as a positive step (and not just for us spectators). Of course at launch, there will still be some exhaust after lift-off that stays local to the pad.

Video of the test from US Launch Report.

https://www.youtube.com/watch?v=KhSQt7p3Yjs


Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/23/2016 07:25 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.

At the same time James Dean tweets the following:

"SES has clarified that profile adjustment made to upcoming launch had no bearing on F9 booster recovery; only impacts upper stage burn."
https://twitter.com/flatoday_jdean/status/702182942458642432

A little confusing.

All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

In truth a higher/faster staging still, in theory, has no bearing on stage recovery, because it could still make it to a landing. It would however have bearing on stage reuse, in yielding a stage that has its integrity compromised.

This might explain how both statements are still true and consistent.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/23/2016 07:34 PM
Over from the updates thread, I just wanted to observe from the static firing that this pad does a great job of directing all the smoke/flame sideways (which seemed to catch the camera operator off-guard), leaving the vehicle visible throughout. That has to be regarded as a positive step (and not just for us spectators). Of course at launch, there will still be some exhaust after lift-off that stays local to the pad.

Video of the test from US Launch Report.

https://www.youtube.com/watch?v=KhSQt7p3Yjs



What do you mean by a positive step? It looks the same as all other launchers out there.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MarekCyzio on 02/23/2016 07:59 PM
In other words, odds of successful stage recovery were low even before SpaceX offered SES extra delta V. But seems to me you could argue they're even lower now. I guess maybe "low" and "lower" are still in the same semantic ballpark.

Anyway, that statement is coming from the payload, not SpaceX, so perhaps we should take it with a grain of salt.

I guess this explains why SpaceX needs Falcon Heavy - F-9 is not capable of delivering heavy loads to GTO and landing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/23/2016 08:03 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.

At the same time James Dean tweets the following:

"SES has clarified that profile adjustment made to upcoming launch had no bearing on F9 booster recovery; only impacts upper stage burn."
https://twitter.com/flatoday_jdean/status/702182942458642432

A little confusing.

All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

In truth a higher/faster staging still, in theory, has no bearing on stage recovery, because it could still make it to a landing. It would however have bearing on stage reuse, in yielding a stage that has its integrity compromised.

This might explain how both statements are still true and consistent.

Wait, doesn't the statement that the adjusted trajectory "only impacts upper stage burn" imply that the extra delta V is coming from the upper stage, not S1, and therefore S1 will stage at the same velocity/altitude as previously planned, and thus have the same amount of residual props for the recovery attempt? That's how I read it.

In which case, the adjustment has "no bearing" on S1 recovery odds, and the statements are consistent.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/23/2016 08:07 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.

At the same time James Dean tweets the following:

"SES has clarified that profile adjustment made to upcoming launch had no bearing on F9 booster recovery; only impacts upper stage burn."
https://twitter.com/flatoday_jdean/status/702182942458642432

A little confusing.

All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

In truth a higher/faster staging still, in theory, has no bearing on stage recovery, because it could still make it to a landing. It would however have bearing on stage reuse, in yielding a stage that has its integrity compromised.

This might explain how both statements are still true and consistent.

Wait, doesn't the statement that the adjusted trajectory "only impacts upper stage burn" imply that the extra delta V is coming from the upper stage, not S1, and therefore S1 will have the same amount of residual props for the recovery attempt? That's how I read it.

In which case, the asjustment has "no bearing" on S1 recovery odds, and the statements are consistent.

Which doesn't make sense. Since the upper stage is expended it should have been delivering them to the best orbit possible to begin with. Something is lost in translation.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: starsilk on 02/23/2016 08:13 PM
Mission press kit: http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf (http://www.spacex.com/sites/spacex/files/spacex_ses9_press_kit_final.pdf)

"Following stage separation, the first stage of the Falcon 9 will attempt an experimental landing on the “Of Course I Still Love You” droneship. Given this mission’s unique GTO profile, a successful landing is not expected."

No timeline for first-stage landing included this time.

At the same time James Dean tweets the following:

"SES has clarified that profile adjustment made to upcoming launch had no bearing on F9 booster recovery; only impacts upper stage burn."
https://twitter.com/flatoday_jdean/status/702182942458642432

A little confusing.

All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

In truth a higher/faster staging still, in theory, has no bearing on stage recovery, because it could still make it to a landing. It would however have bearing on stage reuse, in yielding a stage that has its integrity compromised.

This might explain how both statements are still true and consistent.

Wait, doesn't the statement that the adjusted trajectory "only impacts upper stage burn" imply that the extra delta V is coming from the upper stage, not S1, and therefore S1 will have the same amount of residual props for the recovery attempt? That's how I read it.

In which case, the asjustment has "no bearing" on S1 recovery odds, and the statements are consistent.

Which doesn't make sense. Since the upper stage is expended it should have been delivering them to the best orbit possible to begin with. Something is lost in translation.

except that this is a 'new' stage design (FT), and they now have one flight's worth of data - perhaps they can safely reduce their calculated margins based on the first flight and release a little more performance to the customer.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/23/2016 08:17 PM
I find all these conflicting reports very conflicting.  SES tweets say that the probability of recovery is lower suggesting that S1 is using more propellant rather than S2
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/23/2016 08:18 PM
Quote
except that this is a 'new' stage design (FT), and they now have one flight's worth of data - perhaps they can safely reduce their calculated margins based on the first flight and release a little more performance to the customer.

I think you just nailed it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/23/2016 08:21 PM
I find all these conflicting reports very conflicting.  SES tweets say that the probability of recovery is lower suggesting that S1 is using more propellant rather than S2

Well, SES apparently just told James Dean that there is "no impact" on recovery odds, so maybe starsilk's conjecture is correct, ie that SpaceX has run Monte Carlos based on previous flight performance and has now decided they have a little extra delta V to release.

SpaceX may have made that decision after the first round of statements implying a potential hit to S1 performance, hence the recent "clarification" from SES.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/23/2016 08:23 PM
I find all these conflicting reports very conflicting.  SES tweets say that the probability of recovery is lower suggesting that S1 is using more propellant rather than S2

I agree. Weren't there specific quotes relating to SpaceX sacrificing some recovery odds to help them out. I feel like we would have heard a different message had the first flight just retired some margins on the second stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/23/2016 08:26 PM
I find all these conflicting reports very conflicting.  SES tweets say that the probability of recovery is lower suggesting that S1 is using more propellant rather than S2

I agree. Weren't there specific quotes relating to SpaceX sacrificing some recovery odds to help them out. I feel like we would have heard a different message had the first flight just retired some margins on the second stage.

There were, but maybe SpaceX subsequently did more post-flight analysis and decided they had more performance margin than they thought, which they could release to SES without affecting S1.

(Credit to starsilk for that conjecture)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/23/2016 08:34 PM

Wait, doesn't the statement that the adjusted trajectory "only impacts upper stage burn" imply that the extra delta V is coming from the upper stage, not S1, and therefore S1 will have the same amount of residual props for the recovery attempt? That's how I read it.

In which case, the asjustment has "no bearing" on S1 recovery odds, and the statements are consistent.

Which doesn't make sense. Since the upper stage is expended it should have been delivering them to the best orbit possible to begin with. Something is lost in translation.

Apparently S2 will in fact be providing the extra delta V:

Quote
James Dean – Verified account ‏@flatoday_jdean

The Falcon 9 upper stage will burn for a few more seconds than initially was planned to lift SES-9 to higher orbit, cut days to GEO in half.

So I believe starsilk's conjecture is probably correct: after the initial round of statements implying an S1 performance hit, SpaceX did more post-flight analysis and figured they got more performance than expected from the FT upgrade, which they could release to SES in the form of a slightly longer S2 burn, without depleting S1 residuals for recovery.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: eriblo on 02/23/2016 09:35 PM
The 16s longer S1 burn time compared to ORBCOMM-2 means at least 28 tonnes (minimum throttle) less propellant for the recovery operations this time around...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: RedLineTrain on 02/23/2016 10:11 PM
Reuters is reporting that SES-9 is 5,721 kg rather than ~5,300 kg, based on a pre-flight news conference.

http://www.reuters.com/article/us-space-spacex-ses-idUSKCN0VW2O7

Edit:  Looks like the Reuters article is in error.  Halliwell from SES states that it is 5,271 kg.  See the video in the Florida Today article.

http://www.floridatoday.com/story/tech/science/space/spacex/2016/02/23/spacex-falcon-9-rocket-launch-ses-9-satellite/80568980/?from=global&sessionKey=&autologin=
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris_Pi on 02/23/2016 10:24 PM
The timeline in the press kit has the fairing staying with S2 for 55 seconds after startup - Is this an error in the timeline? Usually it's been ~10-15 seconds. I can't think of any reason to wait so long unless unusually low staging or a really fragile payload still needs it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: okan170 on 02/23/2016 10:29 PM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.

Aha!  The dangers of low resolution strike again...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/23/2016 10:39 PM
The timeline in the press kit has the fairing staying with S2 for 55 seconds after startup - Is this an error in the timeline? Usually it's been ~10-15 seconds. I can't think of any reason to wait so long unless unusually low staging or a really fragile payload still needs it.

If I remember correctly most of the Falcon launches have waited this long. At least DISCOVR and Thales launches did.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/23/2016 11:03 PM
What's up with SpaceX's pre-launch press conferences anymore?  I've not been aware of any since approximately CRS-7.  Am I missing them or are they not having them or did they go somewhat underground? ...Or are they only held for NASA payloaded flights?  I miss the semi-comedy of seeing Hans Koenigsman having to take the bulk of the questions related to the ASDS landing attempt which isn't really his thing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MattMason on 02/23/2016 11:07 PM
What's up with SpaceX's pre-launch press conferences anymore?  I've not been aware of any since approximately CRS-7.  Am I missing them or are they not having them or did they go somewhat underground? ...Or are they only held for NASA payloaded flights?  I miss the semi-comedy of seeing Hans Koenigsman having to take the bulk of the questions related to the ASDS landing attempt which isn't really his thing.

Those pressers do seem to appear only for NASA payloads. A hint may be on who is broadcasting it. If NASA isn't broadcasting it, generally, no presser.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/23/2016 11:33 PM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.

Aha!  The dangers of low resolution strike again...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/24/2016 03:07 AM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.

Aha!  The dangers of low resolution strike again...

So what I seem to be seeing is two openings in the legs which are each covered by blow off covers of the type that are around the base of the payload fairing (if I recall what those look like, can't find an image now for comparison).  Those covers if they are what they may be are to keep rain, birds, etc. out but will blow off when the breeze gets intense.  There are wires running vertically into that opening and the wires are secured with red tape.  But perhaps its the kind of red tape that says "remove before flight"?  Or perhaps the wires are to pre-heat the leg locks.  But if the wires are for leg lock heating then they probably wouldn't have been on the Jason 3 flight(?) which (at the limits of image quality I tend to think I see in this Jason 3 image) they seem to be: http://www.nasa.gov/sites/default/files/thumbnails/image/launchpad.jpg
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: whitelancer64 on 02/24/2016 03:47 AM
So, does anybody know what the weather forecast is like for tomorrow at the Cape?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 02/24/2016 06:50 AM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.

Aha!  The dangers of low resolution strike again...

So what I seem to be seeing is two openings in the legs which are each covered by blow off covers of the type that are around the base of the payload fairing (if I recall what those look like, can't find an image now for comparison).  Those covers if they are what they may be are to keep rain, birds, etc. out but will blow off when the breeze gets intense.  There are wires running vertically into that opening and the wires are secured with red tape.  But perhaps its the kind of red tape that says "remove before flight"?  Or perhaps the wires are to pre-heat the leg locks.  But if the wires are for leg lock heating then they probably wouldn't have been on the Jason 3 flight(?) which (at the limits of image quality I tend to think I see in this Jason 3 image) they seem to be: http://www.nasa.gov/sites/default/files/thumbnails/image/launchpad.jpg

boy thats a tough pic to read but i think you could be right about the wires being on jason.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: dorkmo on 02/24/2016 06:52 AM
ps where should we talk about changes to the transporter erector?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 02/24/2016 07:36 AM
At the SES press briefing it was stated that the first stage burn time is no longer than normal but that at MECO it's doing approx 8000 kph rather than 5000 for the Orbcomm launch (figures are from memory but I think close enough).

So does this imply that the Orbcomm launch wasn't actually going at full thrust? Apologies for  the novice rocket science question.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/24/2016 07:45 AM
Just watched the SES mission briefing. I like that SES guy, very knowledgeable and an interesting presentation.

SES 9 will be slightly super synchronous. He thinks no demo flights are necessary before reflying landed stages. Checks by SpaceX are enough. Two more launches for SES this year, two next year.

On prices he said that SpaceX argued that flight proven rockets should have higher prices. ;D No info on real prices though.

Interesting points on where satellite development is going. They could build satellites that last 25 years but due to technical development service times will actually get shorter. However there is development that satellites can have attach points where new additional hardware can be attached to increase capabilities.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kaputnik on 02/24/2016 07:59 AM
Perhaps Orbcomm was a lofted trajectory?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 02/24/2016 08:02 AM

Perhaps Orbcomm was a lofted trajectory?

Good thought, but I think I heard that separation was at a similar altitude, approx 100 km
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/24/2016 08:11 AM
Well, SES apparently just told James Dean that there is "no impact" on recovery odds, so maybe starsilk's conjecture is correct, ie that SpaceX has run Monte Carlos based on previous flight performance and has now decided they have a little extra delta V to release.

Watching Martin Halliwell's presser right now, he has clarified that all they did was change the 2nd stage plan from a guidance-controlled shutdown to a minimum residual shutdown. So yeah, that implies that as far as S1 goes, the likelihood of recovering it was slim to begin with even before the mission profile change.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/24/2016 08:13 AM
At the SES press briefing it was stated that the first stage burn time is no longer than normal but that at MECO it's doing approx 8000 kph rather than 5000 for the Orbcomm launch (figures are from memory but I think close enough).

So does this imply that the Orbcomm launch wasn't actually going at full thrust?

Recovery experiments SpaceX does mean the first stage is not burned to depletion but the staging velocity is predetermined according to mission requirements. It says virtually nothing about individual vehicle performance.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hopalong on 02/24/2016 08:16 AM
At the SES press briefing it was stated that the first stage burn time is no longer than normal but that at MECO it's doing approx 8000 kph rather than 5000 for the Orbcomm launch (figures are from memory but I think close enough).

So does this imply that the Orbcomm launch wasn't actually going at full thrust? Apologies for  the novice rocket science question.

Orbcomm was a much lighter payload to LEO, SES is a very heavy payload going to a GTO, for the 2nd stage to deliver the SES-9 to the required orbit, the 1st stage needs to push it to 8000 KPH, the 2nd stage does not have the performance to deliver the SES-9 to the required GTO from 5000 KPH.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Rocket Science on 02/24/2016 08:17 AM
So, does anybody know what the weather forecast is like for tomorrow at the Cape?
http://mobile.globalair.com/airport/airport/weather.aspx?aptcode=XMR&display=currentweather
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 02/24/2016 08:27 AM
All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

The press kit shows that the upper stage is performing the normal two burn profile, so the three burn profile I speculated on earlier is not where they they are getting the extra performance.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Steven Pietrobon on 02/24/2016 09:19 AM
From the SES-9 Mission Briefing (http://youtube.com/watch?v=6AuGeQlfR9M) the longer upper stage burn is raising apogee from about 26,000 km to 39,000 km. Acquisition of spacecraft is expected about 22 minutes after separation. SES would have no problem flying a reused first stage. Threw challenge to SpaceX that SES be the first to refly a first stage. Investors really liked that idea. Gwyne from SpaceX joked that it would be more expensive since it was flight proven. Insurance spread across six launches. Martin Halliwell thinks they don't need any demonstrations of reflight to go. Need analysis of status of vehicle of what needs to be done to be flight worthy. SpaceX is working on that now. Use chemical to get to near GEO and then electric for fine tuning of orbit. Second stage separates at about 100 km, similar to Orbcomm. For Orbcomm, separation was at about 5000 km/h (1.4 km/s). SES 9 is between 8000 to 9000 km/h (2.2 to 2.5 km/s). ASDS about 400 miles (640 km) offshore. SES 10 and SES 11 being delivered to Cape in September and October. Launch is about one month later.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: smoliarm on 02/24/2016 10:46 AM
In the above video (thanks, Steven!) --
Martin Halliwell, Chief Technology Officer, SES, says the launch weight of SES-9 is 3721 kg (if I heard correctly).
Since earlier I saw numbers about 5300-5400, I guess its worth to note this new number, for future performance calculations.

Correction:
Ouch! It was my typo - he said "5721", not "3721". Sorry about that  :-[

I meant, the weight is more by ~400 kg.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jimmy Murdok on 02/24/2016 11:20 AM
In the above video (thanks, Steven!) --
Martin Halliwell, Chief Technology Officer, SES, says the launch weight of SES-9 is 3721 kg (if I heard correctly).
Since earlier I saw numbers about 5300-5400, I guess its worth to note this new number, for future performance calculations.
Probably Martin referred to the dry weight. Th 5+ tones should be fueled.
http://www.aerospace-technology.com/projects/ses-9-communication-satellite/

Edit: yes, as confirmed below 5721kg and at late min 10 he speaks about 2,6t of fuel for the hybrid propulsion. Interesting video: customer looks very happy with SpaceX relation, inputs on future modular satellites connecting each other to extend life.
Working with the vendor ( I guess SpaceX) on a mechanical and com's interface and a second cargo, which is launched on a later launch where the primary satellite acts as a transport of the secondary payload and takes it to the old GEO sat and plug it to extend capability. New sat continues to perform its main mission. Min 17
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/24/2016 11:30 AM
He clearly said "5721 kilos" in the video.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: saliva_sweet on 02/24/2016 11:33 AM
In the above video (thanks, Steven!) --
Martin Halliwell, Chief Technology Officer, SES, says the launch weight of SES-9 is 3721 kg (if I heard correctly).
Since earlier I saw numbers about 5300-5400, I guess its worth to note this new number, for future performance calculations.

I clearly hear 5721 kilos. I guessthe extra ~400 kg is the payload adapter.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: SVBarnard on 02/24/2016 11:40 AM
At the SES press briefing it was stated that the first stage burn time is no longer than normal but that at MECO it's doing approx 8000 kph rather than 5000 for the Orbcomm launch (figures are from memory but I think close enough).

So does this imply that the Orbcomm launch wasn't actually going at full thrust? Apologies for  the novice rocket science question.

Orbcomm was a much lighter payload to LEO, SES is a very heavy payload going to a GTO, for the 2nd stage to deliver the SES-9 to the required orbit, the 1st stage needs to push it to 8000 KPH, the 2nd stage does not have the performance to deliver the SES-9 to the required GTO from 5000 KPH.

has MECO ever occured at 8000 kph?

Another, so I have seen other posters say that when the Falcon Heavy is pushed to it's limits the center booster will land downrange on the barge instead of returning back to land, well what is the velocity of this MECO? Would it be 8000 kph? I mean why is Spacex being so pessimistic about sticking this landing?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: hopalong on 02/24/2016 11:53 AM
At the SES press briefing it was stated that the first stage burn time is no longer than normal but that at MECO it's doing approx 8000 kph rather than 5000 for the Orbcomm launch (figures are from memory but I think close enough).

So does this imply that the Orbcomm launch wasn't actually going at full thrust? Apologies for  the novice rocket science question.

Orbcomm was a much lighter payload to LEO, SES is a very heavy payload going to a GTO, for the 2nd stage to deliver the SES-9 to the required orbit, the 1st stage needs to push it to 8000 KPH, the 2nd stage does not have the performance to deliver the SES-9 to the required GTO from 5000 KPH.

has MECO ever occured at 8000 kph?

Another, so I have seen other posters say that when the Falcon Heavy is pushed to it's limits the center booster will land downrange on the barge instead of returning back to land, well what is the velocity of this MECO? Would it be 8000 kph? I mean why is Spacex being so pessimistic about sticking this landing?

It is not about the speed of the 1st stage, it is the amount of fuel left to perform the breaking/re-entry/landing burns. the FT is using just about all its fuel to get the US/payload to the required speed so that the US can complete the mission. The FH, due to the assistance of the side boosters, will have a lot more fuel available at separation to do the landing.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Llian Rhydderch on 02/24/2016 12:28 PM
On velocity at second stage separation:

The latest info, directly from Irene Klotz at Reuters (http://www.reuters.com/article/us-space-spacex-ses-idUSKCN0VW2O7) says: "the rocket launching this week will be flying almost twice as fast as the one used in December - between 4,971- to 5,592 mph ( 8,000- to 9,000 kph), compared to 3,107 mph (5,000 kph) - by the time it separates from the second-stage motor, SpaceX said."

I think this makes sense when compared to what was said earlier in design for F9R, from back in 2012.  That is all summarized rather nicely, with the sources, in the Wikipedia article on the reusable technology (https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_development_program): 
Quote
If the technology is used on a reusable Falcon 9 rocket, the first-stage separation would occur at a velocity of approximately 2.0 km/s (6,500 km/h; 4,100 mph; Mach 6) rather than the 3.4 km/s (11,000 km/h; 7,000 mph; Mach 10) for an expendable Falcon 9, to provide the residual fuel necessary for the deceleration and turnaround maneuver and the controlled descent and landing.

So, new/actual info with real F9 FT hardware:  Orbcomm separated at 5,000 km/h, SES-9 expected to separate at up to 9,000 km/h.

The original (public) design numbers were projected to be around 6,500 km/h for reusable F9, and 11,000 km/h for an expendable F9.

In this light, it seems that the SES-9 launch is approaching expendable velocity, enough that SpaceX is saying it is not likely they can recover the SES-9 first stage today, but that they apparently think they are on the edge, and they might be able to pull off a droneship recovery, by skipping the boostback burn, and nursing the stage down from the 8,000-9,000 km/h velocity they expect directly to a way-downrange droneship.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CorvusCorax on 02/24/2016 12:37 PM
I think that was indeed a very interesting bit of information, especially the part of "how" that attach points would be utilized.

The idea is 1. That the satellite bus/main frame has excess power and station keeping ability for its mass/internal payload, but external attachment points that allow both mechanical, electrical and data connection in an extendible way.

But GEO is way too far up to service anything there with a deliberate "service mission" or even a manned mission like they did for Hubble. To even get there you'd have to spend as much d/v as for a new satellite, so you might as well do that and launch a new satellite.

Which is exactly what they are going to do do. But whenever they send a brand new satellite up there, for any slot in the GEO, it might include a tender+ extension module as a secondary payload. It well then not sail straight for its intended slot but first visit the slot of the to be served satellite, deploy the tender there (which autonomously will attach the extension module to the extension attach point of the existing satellite) and then do the transfer to its own slot.

Switching slots is - although time consuming and potentially tricky due to the crowded environment - very low delta-v maneuvers and can be done almost arbitrarily far with no more propellant use than normal station keeping. The only down-side would be an extended time to service for the new sat.

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: matthewkantar on 02/24/2016 01:48 PM
Someone somewhere has transposed some numbers, would not want to bet on the satalite's mass at 5721 kg or 5217 kg. substantial difference though.                                                                                               Matthew
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/24/2016 01:56 PM
From the SES-9 Mission Briefing (http://youtube.com/watch?v=6AuGeQlfR9M) ....Threw challenge to SpaceX that SES be the first to refly a first stage. Investors really liked that idea. Gwyne from SpaceX joked that it would be more expensive since it was flight proven. Insurance spread across six launches. Martin Halliwell thinks they don't need any demonstrations of reflight to go.

Thanks for this summary, Steven.

Wow, SES says they don't even need a reflight demo before reusing a booster? That's umm...courageous. Not that I think he's wrong. But that's a bold move for a payload, and their insurance company. I guess the "insurance spread across six launches" helps.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: chalz on 02/24/2016 02:05 PM
Someone somewhere has transposed some numbers, would not want to bet on the satalite's mass at 5721 kg or 5217 kg. substantial difference though.
The interesting thing to me, though it is probably familiar to others here, is that around 40% of that is chemical propellant. And all of it will be burnt just to get it to orbit, even with the help from the second stage.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: RedLineTrain on 02/24/2016 02:08 PM
Someone somewhere has transposed some numbers, would not want to bet on the satalite's mass at 5721 kg or 5217 kg. substantial difference though.

The difference is from SES itself.  In the first video, its CTO says 5,271 kg.  In the second video, he says 5,721 kg.

http://www.floridatoday.com/story/tech/science/space/spacex/2016/02/23/spacex-falcon-9-rocket-launch-ses-9-satellite/80568980/?from=global&sessionKey=&autologin=

https://www.youtube.com/watch?v=6AuGeQlfR9M
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: CorvusCorax on 02/24/2016 02:26 PM
Awesome feature article for the mission, by William Graham:

http://www.nasaspaceflight.com/2016/02/spacex-falcon9-ses-9-launch/

--

And a reminder, again - this is the update only/launch thread. Discussion goes in the discussion thread. Crazy, I know! ;)

Also, ensure you are logged into the forum during the event. If we become swamped, we'll remove "guest" access for a short while to keep the place running smoothly.



As directed, bringing this bit of discussion here. The mentioned article says:

Quote
The first stage, meanwhile, will restart a subset of its engines for a series of three burns to facilitate the experimental recovery attempt.

The first of these, a boostback manoeuvre, will adjust its course towards the location of the Autonomous Spaceport Drone Ship (ASDS) downrange. The second will slow the stage for reentry while the third will begin shortly before landing to provide a controlled descent onto the deck of the barge.

Timings for the landing have not been confirmed.

Are you sure? I thought it was mentioned that the boostback burn was to be skipped altogether for this landing attempt, resulting in the higher than normal reentry velocity. At least that's how I interpreted the list of events mentioned in the SES9 press conference.

also

Quote
Three minutes and 29 seconds later the satellite will separate from the Falcon 9 to begin its mission. SES-9 will use its own electric propulsion system to raise and circularise its orbit as it heads towards its geostationary slot.

In the same SES press conference it was mentioned that the sattelite will use its entire 2 tones of chemical propellant to circularize its orbit and the electric propulsion only for fine tune and station keeping - thus resulting in a significant reduction in time to service.



Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/24/2016 03:37 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ugordan on 02/24/2016 03:37 PM
Pics of static fire on SpaceX's Instagram and Facebook.

Enjoy, Matthew

Seems like there are two rounded rectangles on either side of the leg here, a little bit inset.  Previous flights' legs had a roughly square protrusion (small fairing?) here.
It also seems they are very faintly visible on this image tweeted by the 45th Space Wing.
https://twitter.com/45thSpaceWing/status/701891806255046657

Tape. But I am noticing this string/wire first time.

I went back and saw the same kind of thing on the Jason-3 vehicle. Curious to be running exposed wire like that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: cscott on 02/24/2016 03:40 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...
Average price for the fleet goes down.  Cost for first flight of unproven rocket goes *way* down.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: whitelancer64 on 02/24/2016 03:52 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...

It's clearly meant as a joke.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Semmel on 02/24/2016 03:52 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...

He said it was a joke by Gwynne Shotwell and mentioned in the context of insurance for the payload.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: fthomassy on 02/24/2016 04:00 PM
He said it was a joke by Gwynne Shotwell and mentioned in the context of insurance for the payload.
Interesting cost balance.  Re-flight cost must go down (vs. first flight) more than insurance costs go up to make it a value to the customer. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: rpapo on 02/24/2016 04:03 PM
He said it was a joke by Gwynne Shotwell and mentioned in the context of insurance for the payload.
Interesting cost balance.  Re-flight cost must go down (vs. first flight) more than insurance costs go up to make it a value to the customer.
Insurance would only be higher until the reliability of a reused stage can be determined.  The insurance industry has 60 years of history for expendable rockets, and none for reusable rockets.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Kabloona on 02/24/2016 04:15 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...

It's clearly meant as a joke.

Thanks. I guess my sense of humor has deserted me.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: guckyfan on 02/24/2016 04:27 PM
On prices he said that SpaceX argued that flight proven rockets should have higher prices.

Huh? So reusability is now a way to make spaceflight more expensive?

Please tell me Elon did not really mean this...

It's clearly meant as a joke.

Thanks. I guess my sense of humor has deserted me.

Yes, for now it is a joke.  :) I should have made that clear.

Long term it should actually be that way. The price for the first flight needs to go down and the second or third is more expensive because safer, still cheaper than the first flight now. This has been argued before and I believe it may come true. But as long as NASA and the Airforce demand a new rocket and are willing to pay premium prices the present situation is more advantageous for SpaceX and the customers. When government customers pay the full price of an expendable the stages are basically free for commercial flights.

Edit: But a continued discussion is not for this thread.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/24/2016 04:42 PM
The probability of success in landing SES-9 has been described as being quite low and has been described as reasonably good and everything in between.  Here we have Trip Harriss who is SpaceX's head of recovery operations weighing in with an optimistic opinion;

https://twitter.com/spacextrip
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 02/24/2016 04:46 PM
All a booster can do is get US+payload to staging. US is responsible for orbital velocity and margin for stage shortfall (you can't minimize this margin). 3 burns can improve this, more props e.g. more densified can get you this.

The press kit shows that the upper stage is performing the normal two burn profile, so the three burn profile I speculated on earlier is not where they they are getting the extra performance.

No they aren't. Thanks for the sep velocity. Have you heard any mention of stage sep altitude? And have they called out retro/entry/terminal burn timing/durations?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: starsilk on 02/24/2016 04:48 PM

Wait, doesn't the statement that the adjusted trajectory "only impacts upper stage burn" imply that the extra delta V is coming from the upper stage, not S1, and therefore S1 will have the same amount of residual props for the recovery attempt? That's how I read it.

In which case, the asjustment has "no bearing" on S1 recovery odds, and the statements are consistent.

Which doesn't make sense. Since the upper stage is expended it should have been delivering them to the best orbit possible to begin with. Something is lost in translation.

Apparently S2 will in fact be providing the extra delta V:

Quote
James Dean – Verified account ‏@flatoday_jdean

The Falcon 9 upper stage will burn for a few more seconds than initially was planned to lift SES-9 to higher orbit, cut days to GEO in half.

So I believe starsilk's conjecture is probably correct: after the initial round of statements implying an S1 performance hit, SpaceX did more post-flight analysis and figured they got more performance than expected from the FT upgrade, which they could release to SES in the form of a slightly longer S2 burn, without depleting S1 residuals for recovery.

there were some timing 'discrepancies' with the first FT flight - things were happening sooner than the timeline provided, by several seconds. there was speculation at the time that the rocket performed better than predicted.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: yokem55 on 02/24/2016 05:19 PM
So, looking at the pic of the encapsulated spacecraft from the update thread - http://forum.nasaspaceflight.com/index.php?topic=39348.msg1494323#msg1494323

Did they do the spacecraft encapsulation/processing in the VAB?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: The Roadie on 02/24/2016 05:20 PM
Not *the* VAB. They lease one closer to the pad that used to be for Titans.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: MechE31 on 02/24/2016 05:23 PM
So, looking at the pic of the encapsulated spacecraft from the update thread - http://forum.nasaspaceflight.com/index.php?topic=39348.msg1494323#msg1494323

Did they do the spacecraft encapsulation/processing in the VAB?

That's the SMAB/SPIF/PPF/whatever other name it has today

http://wikimapia.org/6350003/Solid-Motor-Assembly-Building-Inactive-Satellite-Processing-and-Integration-Facility-SPIF
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Rik ISS-fan on 02/24/2016 06:01 PM
SpaceX has a payload processing facility at Cape Canaveral called Hangar X or Hangar AO. Most likely SES9 was prepared there.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Ilikeboosterrockets on 02/24/2016 06:02 PM
Does anybody know if on board video will be released from this stage, or if they plan to release any from previous missions? Can anybody think of a reason why they haven't released the ORBCOMM on board footage that Chris teased us about?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/24/2016 06:07 PM
SpaceX has a payload processing facility at Cape Canaveral called Hangar X or Hangar AO. Most likely SES9 was prepared there.

No, That is only for the Falcon and not payloads and it only handles nonhazardous operations.  The Spacex payload processing facility is the SPIF in the SMAB.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mattshup on 02/24/2016 06:09 PM
Does anybody know if on board video will be released from this stage, or if they plan to release any from previous missions? Can anybody think of a reason why they haven't released the ORBCOMM on board footage that Chris teased us about?

Because they don't have to if they don't want to?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Mader Levap on 02/24/2016 06:11 PM
Does anybody know if on board video will be released from this stage, or if they plan to release any from previous missions? Can anybody think of a reason why they haven't released the ORBCOMM on board footage that Chris teased us about?
My guess would be ITAR and/or propertiary info that - if published - would only make it easier for competition.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mrhuggy on 02/24/2016 06:12 PM
NWS has issued a Warning for possible thunderstorms, tornados and  water spouts. The area covered also includes the cape. This warning ends 16:00 PM est.

It may effect prepations for the launch today.

Quote

940
WHUS52 KMLB 241902
SMWMLB
AMZ550-552-570-242100-
/O.NEW.KMLB.MA.W.0020.160224T1902Z-160224T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
202 PM EST WED FEB 24 2016

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
  FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM...
  FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM...
  VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM...

* UNTIL 400 PM EST

* AT 157 PM EST...A LINE OF SHOWERS AND THUNDERSTORMS CAPABLE OF
  PRODUCING STRONG WIND GUSTS WAS APPROACHING THE INTERSTATE 4
  CORRIDOR FROM VOLUSIA COUNTY TO SOUTH LAKE COUNTY. MOVEMENT WAS
  EAST AT 30 KNOTS. ISOLATED WATERSPOUTS ARE POSSIBLE AS THE SHOWERS
  AND STORMS MOVE OFFSHORE.

  HAZARD...WATERSPOUTS...WIND GUSTS 34 KNOTS OR GREATER...AND SMALL
           HAIL.

  SOURCE...RADAR INDICATED.

  IMPACT...WATERSPOUTS CAN EASILY OVERTURN BOATS AND CREATE LOCALLY
           HAZARDOUS SEAS. SMALL CRAFT COULD BE DAMAGED IN BRIEFLY
           HIGHER WINDS AND SUDDENLY HIGHER WAVES.

* LOCATIONS IMPACTED INCLUDE...
  THE INTRACOASTAL AND ATLANTIC WATERS BETWEEN FLAGLER BEACH AND
  CAPE CANAVERAL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO SAFE HARBOR UNTIL HAZARDOUS WEATHER PASSES.

THUNDERSTORMS CAN PRODUCE SUDDEN WATERSPOUTS. WATERSPOUTS CAN EASILY
OVERTURN BOATS AND CREATE LOCALLY HAZARDOUS SEAS. SEEK SAFE HARBOR
IMMEDIATELY.

&&
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Joffan on 02/24/2016 06:30 PM
NWS has issued a Warning for possible thunderstorms, tornados and  water spouts. The area covered also includes the cape. This warning ends 16:00 PM est.

It may affect preparations for the launch today.


This might be a case where SpaceX's shift to later load of cryogenics gives them an advantage; they won't have to worry about a LOx-filled tank sitting n the rain for hours.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Rik ISS-fan on 02/24/2016 06:31 PM
No, That is only for the Falcon and not payloads and it only handles nonhazardous operations.  The Spacex payload processing facility is the SPIF in the SMAB.

Jim Your right.
I misread the Falcon 9 user guide.
Clients get office space in Hangar AO (/X) and the payloads are processed at the Large Processing Facility, the former solid motor assembly building. It is located south west of LC-40. 
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/24/2016 06:33 PM

This might be a case where SpaceX's shift to later load of cryogenics gives them an advantage; they won't have a LOx-filled tank sitting n the rain for hours.

Why would that be an advantage?

A.  Ice insulates the tank
b.  It shakes off during launch
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Joffan on 02/24/2016 06:51 PM

This might be a case where SpaceX's shift to later load of cryogenics gives them an advantage; they won't have to worry about a LOx-filled tank sitting n the rain for hours.

Why would that be an advantage?

A.  Ice insulates the tank
b.  It shakes off during launch

OK, so probably not a concern then. Although there was some talk of the landing leg problem possibly being associated with ice build-up from the fog on Jason-3 (which didn't have late prop load).

Is there any difference, in amount or characteristics, between the ice just built up from Florida humidity and the ice build-up in rain?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/24/2016 07:01 PM
The probability of success in landing SES-9 has been described as being quite low and has been described as reasonably good and everything in between.  Here we have Trip Harriss who is SpaceX's head of recovery operations weighing in with an optimistic opinion;

https://twitter.com/spacextrip

In case you missed it the first time like I did check out the way that he's taken the graphic swoosh that existed on the hotel notepad and doodled it into a SpaceX "X".  Must be a fun place to work (SpaceX, not Marriot).  8)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: DatUser14 on 02/24/2016 07:05 PM
Wind gusting to nearly 6 knots at the LZ, according to NOAA buoy. http://www.ndbc.noaa.gov/station_page.php?station=41047&amp;unit=M&amp;tz=EST
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lar on 02/24/2016 07:15 PM
Please forgive me:

I will not be able to watch the webcast(s) of tonight's launch because I have to attend a college class from 23:30 UTC on February 24th to 01:20 UTC on February 25th (in Central Time, it's 5:30 PM to 7:20 PM). I'm a student at the University of Arkansas, so sometimes, launches can conflict with my class schedule.

You are forgiven... life happens. I was in the air once during a launch, in fact so...

(Mod note: don't everyone else post about how you can't make the launch, perhaps that belongs in the party thread as does this pair, let me ponder)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: ericr on 02/24/2016 07:20 PM
OK, please help. 

Can't seem to find the link to the live video stream of this launch here at NSF.  I've tried quick search of this and other SES-9 threads for terms like: Video, Stream, Link, Live, Feed, etc. with no luck.

Somehow I must be overlooking the obvious.

Thanks!
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: GabrielP on 02/24/2016 07:23 PM
It's usually http://www.spacex.com/webcast (http://www.spacex.com/webcast).

Youtube links:
Full hosted webcast: https://www.youtube.com/watch?v=Ml1RO4IcOG0 (https://www.youtube.com/watch?v=Ml1RO4IcOG0)
Rocket views, launch countdown audio and telemetry info - technical webcast: https://www.youtube.com/watch?v=6HSb_yBnJXA (https://www.youtube.com/watch?v=6HSb_yBnJXA)
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: LastStarFighter on 02/24/2016 08:20 PM
Someone somewhere has transposed some numbers, would not want to bet on the satalite's mass at 5721 kg or 5217 kg. substantial difference though.

The difference is from SES itself.  In the first video, its CTO says 5,271 kg.  In the second video, he says 5,721 kg.

http://www.floridatoday.com/story/tech/science/space/spacex/2016/02/23/spacex-falcon-9-rocket-launch-ses-9-satellite/80568980/?from=global&sessionKey=&autologin=

https://www.youtube.com/watch?v=6AuGeQlfR9M

Didn't see if this was cleared up. The official SES fact sheet says 5271kg wet.

http://www.ses.com/ses-9-factsheet
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: AnalogMan on 02/24/2016 08:45 PM
OK, please help. 

Can't seem to find the link to the live video stream of this launch here at NSF.  I've tried quick search of this and other SES-9 threads for terms like: Video, Stream, Link, Live, Feed, etc. with no luck.

Somehow I must be overlooking the obvious.

Thanks!

Posted earlier:

For those who prefer  good old links

technical webcast:
https://www.youtube.com/watch?v=6HSb_yBnJXA&feature=youtu.be (https://www.youtube.com/watch?v=6HSb_yBnJXA&feature=youtu.be)

Full webcast:
https://www.youtube.com/watch?v=Ml1RO4IcOG0&feature=youtu.be (https://www.youtube.com/watch?v=Ml1RO4IcOG0&feature=youtu.be)

Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: jaufgang on 02/24/2016 09:43 PM
The launch time for this flight is just a few minutes after the end of "civil twilight" and the beginning of "nautical twilight," meaning the center of the sun will be just about 6° below the horizon and there will be a very small amount of residual sunlight in the sky.  (see http://www.timeanddate.com/astronomy/usa/cape-canaveral)

With the skies looking clear in the area I'm guessing/hoping this could result in some interesting lighting effects, causing the launch to look different from some of the other nighttime launches where the sky was pitch black.  What would be amazing is if the the fuselage and the rocket trail manage to catch some illumination from the sun causing them to glow as it rises against the dark sky, especially at higher altitudes.

Does anyone know if this is likely, or will the sun be to far below the horizon at that point for this to happen?  Maybe 10-15 minutes earlier would have made it more likely, in the middle of civil twilight?

edit:  Here's a website with some fantastic photos of rocket trails at twilight: http://scribol.com/science/space/rocket-trails-at-twilight-illuminate-the-sky.  Hoping we'll see some of this tonight.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lee Jay on 02/24/2016 10:19 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/24/2016 10:22 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?

Also possibly things related to ASDS.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: OxCartMark on 02/24/2016 10:23 PM
Does anyone know if this is likely, or will the sun be to far below the horizon at that point for this to happen?  Maybe 10-15 minutes earlier would have made it more likely, in the middle of civil twilight?

I believe that DSCOVR was launched just a few minutes earlier in the day but after 6pm on Feb 11th 2015 and into clear skies so take a look at what happened there and it isn't much of a jump to what we're going to see today.  ...Other than today we're launching a much more immovable object using a 30% more irresistable force.

https://www.youtube.com/watch?v=OvHJSIKP0Hg
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Jim on 02/24/2016 10:24 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?

Also possibly things related to ASDS.

Don't scrub for that when there is a chance that landing is not a given
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Chris Bergin on 02/24/2016 10:24 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?

Also possibly things related to ASDS.

They'd never scrub for the ASDS. Not a primary objective. Customer first.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: mn on 02/24/2016 10:24 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?

I think it just means they are not ready to tell us why (surprise surprise). 'healthy' doesn't mean there wasn't a problem that led them to decide to scrub, (nor does it mean there was a problem).

And just to add another 2 cents, if it was weather they would likely have said that.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Comga on 02/24/2016 10:26 PM
From the UPDATES Thread
Updated status: Static Fire aiming for Monday. Launch Wednesday.

That's only two days from static fire to launch.
Using the SpaceX Scrubs Thread (http://forum.nasaspaceflight.com/index.php?topic=36507.msg1311378#msg1311378) as the reference, the historical record of that interval is:

Falcon 9 Flight Number     
  1   2   3   4   5    6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21
Stat Fire to Launch Days 
83   4   ?    8   5  10   7   8  10   3   6   15   4  22   11   6    3    5    2   3  >2
(snip)

No two day interval this time.
This could be through no fault of the vehicle or payload.

swebster: It is unlikely they would hold the launch for the landing.  This is not Orbcomm, and the probability of a successful landing is said to be low in any case and they are making efforts to get this payload on orbit sooner. 

edit: grammar
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: GalacticIntruder on 02/24/2016 10:28 PM
Monte Carlo again?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: sewebster on 02/24/2016 10:29 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn't that just leave GSE and weather?

Also possibly things related to ASDS.

They'd never scrub for the ASDS. Not a primary objective. Customer first.

But isn't that almost what they said last time?! (Orbcomm) 20% greater chance in sims or something?

Edit: just read some of the previous replies more thoroughly. I recognize this is a lower chance recovery. Not suggesting an ASDS related delay is likely, but perhaps given what they've said in the past, the chance is not 0%?
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: Lee Jay on 02/24/2016 10:33 PM
Hmmm...if it were the rocket, they wouldn't have said it was healthy.
If it was weather, they would have waited to see if it improved given the long launch window.
If it was the range, same thing - see if you can clear it during the window.
If it was GSE, see if you can fix it during the window.

Maybe they felt they needed to do some more mission assurance like trajectory, data analysis from the static fire, software, etc.

Just guessing here.  As Chris said, they stopped before prop load, and the statements are confusing as to the cause of the scrub.

I'm sure it makes sense if you understand it.

I'm going to go with "Elon has a tummy ache and didn't want to miss the launch."  Yeah, that's it.  I'm sure of it.
Title: Re: SpaceX Falcon 9 FT - SES-9 - March 4, 2016 - DISCUSSION
Post by: the_other_Doug on 02/24/2016 10:38 PM
If the rocket and spacecraft are healthy, and they scrubbed anyway, doesn&#