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SpaceX Vehicles and Missions => SpaceX Missions Section => Topic started by: gongora on 11/03/2016 04:22 PM

Title: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 11/03/2016 04:22 PM
NSF Threads for Inmarsat 5 F4 : Discussion (https://forum.nasaspaceflight.com/index.php?topic=41560.0) / Updates (http://forum.nasaspaceflight.com/index.php?topic=42846.0) / L2 Coverage May-June (http://forum.nasaspaceflight.com/index.php?topic=42839.0) / ASDS (https://forum.nasaspaceflight.com/index.php?board=66.0) / Party (http://forum.nasaspaceflight.com/index.php?topic=42585.0)
NSF Articles for Inmarsat 5 F4 :
   SpaceX improving launch cadence, testing new goals (https://www.nasaspaceflight.com/2017/05/spacex-launch-cadence-new-goals/)
   Falcon 9 readies for Static Fire test ahead of Inmarsat 5 F4 mission (https://www.nasaspaceflight.com/2017/05/falcon-9-static-fire-1-inmarsat5f4/)
   SpaceX Falcon 9 in flawless Inmarsat-5 F4 launch (https://www.nasaspaceflight.com/2017/05/expendable-falcon-9-inmarsat-5-f4-launch/)

Successful launch of 6086kg Inmarsat-5 F4 on May 15, 2017 at 1921 EDT (2321 UTC) on Falcon 9 (expendable first stage 1034) from LC-39A at Cape Canaveral.


Other SpaceX resources on NASASpaceflight:
   SpaceX News Articles (Recent) (http://www.nasaspaceflight.com/tag/spacex/)  /   SpaceX News Articles from 2006 (Including numerous exclusive Elon interviews) (http://forum.nasaspaceflight.com/index.php?topic=21862.0)
   SpaceX Dragon Articles (http://www.nasaspaceflight.com/tag/dragon/)  /  SpaceX Missions Section (with Launch Manifest and info on past and future missions) (https://forum.nasaspaceflight.com/index.php?board=55.0)
   L2 SpaceX Section (https://forum.nasaspaceflight.com/index.php?board=60.0)



[2013] Inmarsat to purchase fourth Inmarsat-5 satellite from Boeing (http://http://www.inmarsat.com/news/inmarsat-to-purchase-fourth-inmarsat-5-satellite-from-boeing-2/)
Quote
Inmarsat has triggered an option to purchase a fourth Inmarsat-5 spacecraft – under its existing contract with Boeing Satellite Systems International.

The programme schedule from Boeing has a satellite delivery date of mid-2016.

The fourth satellite will have a dual strategic role – firstly, as an early available spare in the unlikely event of a launch failure of any of the first three Inmarsat-5 satellites.
...
Boeing will immediately begin construction of the fourth Inmarsat-5 satellite. The total cost of the option and certain related expenditure will be between US$220 million and US$250 million.

Inmarsat: The I5 Satellites (http://www.inmarsat.com/the-i-5-satellites/)
Quote
The I-5 satellites, based on Boeing’s proven 702HP spacecraft platform, will deliver consistent high-performance download speeds of up to 50Mbps and up to 5Mbps over the uplink from their position in geosynchronous orbit. Their impressive statistics include:

    The I-5 body – at 6.98 metres (22.9ft), the height of a double decker bus
    User beams – 89 Ka-band beams generated by two transmit and two receive apertures
    Spot beams – six steerable spot beams to direct additional capacity where it is needed
    Solar arrays – a wingspan of 33.8 metres (111ft)
    Solar panels – five panels of ultra triple-junction gallium arsenide solar cells generate 15 kW of power at start of service and 13.8 kW by end of life
    Station-keeping thrusters – a xenon ion propulsion system (XIPS) handles in-orbit manoeuvring
    Launch mass – 6,100kg
    Mission lifespan – 15 years

Inmarsat 5 F4 on Gunter's Space Page (http://space.skyrocket.de/doc_sdat/inmarsat-5.htm)

Inmarsat Jul 2 2014: launch contract announcement (http://www.inmarsat.com/press-release/inmarsat-appoints-spacex-future-satellite-launches/) originally mentioned in this NSF thread Topic: Inmarsat to use SpaceX for satellite launches (http://forum.nasaspaceflight.com/index.php?topic=35104.0)

So Inmarsat 5 F4 really is launching on Falcon, and EuropaSat/HellasSat 3 may move to a different launch vehicle but final decision not made yet.

SpaceNews: Inmarsat, juggling two launches, says SpaceX to return to flight in December (http://spacenews.com/inmarsat-juggling-two-launches-says-spacex-to-return-to-flight-in-december/)
Quote
Inmarsat has three launch contracts with SpaceX. Up to now, it had planned to launch its Inmarsat 5-F4 Ka-band broadband mobile communications satellite on a Falcon 9 in late 2016; an S-band aeronautical-connectivity satellite on a new Falcon Heavy rocket in early 2017; and the first of the Inmarsat-6 satellites after that.
Quote
Inmarsat has decided to stick with SpaceX for the 5-F4 satellite, but to seek alternatives for the mid-2017 S-band satellite launch.

“It’s largely a function of where you are in the manifest,” Pearce said of Inmarsat’s launch reasoning. “With Inmarsat 5 F4, we’re well up in the queue — I think we are number five or six.
...

There was an interesting comment on Reddit by someone who appears to be a SpaceX employee:
Reddit comment by /u/Spiiice (https://www.reddit.com/r/spacex/comments/54t20h/rspacex_ask_anything_thread_october_2016_25/d8v9qrm/?context=3)
Quote
We have more than one launch on the manifest that is considered expendable, and no recovery will be attempted.

This would make a lot of sense for a couple payloads that were originally assumed to be flying on FH (Inmarsat 5 F4, Europasat).

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: WHAP on 11/04/2016 05:46 PM
Potential change in launch vehicle for "an" Inmarsat payload, consistent with information above. http://www.wsj.com/articles/elon-musks-spacex-may-lose-inmarsat-launch-order-1478165008
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 11/04/2016 06:28 PM
Potential change in launch vehicle for "an" Inmarsat payload, consistent with information above. http://www.wsj.com/articles/elon-musks-spacex-may-lose-inmarsat-launch-order-1478165008

The payload that may change launchers is Europasat, not this one.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: russianhalo117 on 11/06/2016 08:43 PM
Potential change in launch vehicle for "an" Inmarsat payload, consistent with information above. http://www.wsj.com/articles/elon-musks-spacex-may-lose-inmarsat-launch-order-1478165008
but it just got I-5-F4  from Proton last month.
Potential change in launch vehicle for "an" Inmarsat payload, consistent with information above. http://www.wsj.com/articles/elon-musks-spacex-may-lose-inmarsat-launch-order-1478165008

The payload that may change launchers is Europasat, not this one.
Europasat chose during investor call to defer discussion of a launcher switch until the next quarterly conference call.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: vapour_nudge on 12/09/2016 08:11 AM
So is this the launch they just lost to Arianespace due to their delays?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 12/09/2016 02:26 PM
So is this the launch they just lost to Arianespace due to their delays?

Once again, no.  This isn't the S-band satellite.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mrcln on 12/09/2016 03:36 PM
Inmarsat's own press release on this seems to explicitly state that this is not the launch they moved to Arianespace:

Quote
Inmarsat will launch Inmarsat-5 F4, a Global Xpress (GX) satellite, with SpaceX.  This launch is planned for H1 2017 and Inmarsat is looking forward to continuing to work with SpaceX going forward.

from: http://www.inmarsat.com/news/inmarsat-signs-contract-launch-ean-satellite-arianespace/ (http://www.inmarsat.com/news/inmarsat-signs-contract-launch-ean-satellite-arianespace/)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: WHAP on 12/09/2016 04:01 PM
So is this the launch they just lost to Arianespace due to their delays?

Once again, no.  This isn't the S-band satellite.

Everyone wants to be like Jim.  I realize vapour_nudge didn't ask what it was, but sometimes that's more helpful than saying what it wasn't.  According to Aerospace Daily, this was "the Inmarsat S-band/Hellas-Sat 3 telecommunications spacecraft". 
http://aviationweek.com/awinspace/inmarsat-switches-launch-spacex-arianespace
Also https://forum.nasaspaceflight.com/index.php?topic=40756.msg1617381#msg1617381
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 12/09/2016 04:12 PM
So is this the launch they just lost to Arianespace due to their delays?

Once again, no.  This isn't the S-band satellite.

Everyone wants to be like Jim.  I realize vapour_nudge didn't ask what it was, but sometimes that's more helpful than saying what it wasn't.  According to Aerospace Daily, this was "the Inmarsat S-band/Hellas-Sat 3 telecommunications spacecraft". 
http://aviationweek.com/awinspace/inmarsat-switches-launch-spacex-arianespace
Also https://forum.nasaspaceflight.com/index.php?topic=40756.msg1617381#msg1617381

Just to be clear, when WHAP says "this" he's talking about the satellite that switched launchers (Europasat/HellasSat 3), which is not Inmarsat 5 F4.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: dglow on 01/20/2017 02:32 AM
The manifest thread lists this mission as GTO with RTLS. Is that accurate or no?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 01/20/2017 02:36 AM
The manifest thread lists this mission as GTO with RTLS. Is that accurate or no?

No.  I'm betting on expendable for this flight, but we'll see if it ends up being an ASDS landing.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ZachS09 on 01/20/2017 03:53 AM
The manifest thread lists this mission as GTO with RTLS. Is that accurate or no?

No.  I'm betting on expendable for this flight, but we'll see if it ends up being an ASDS landing.

We've never seen an expendable Falcon 9 mission since TürkmenÄlem 52E/MonacoSat in April 2015.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: old_sellsword on 01/20/2017 04:44 AM
The manifest thread lists this mission as GTO with RTLS. Is that accurate or no?

No.  I'm betting on expendable for this flight, but we'll see if it ends up being an ASDS landing.

We've never seen an expendable Falcon 9 mission since TürkmenÄlem 52E/MonacoSat in April 2015.

Well expect to see some in the future.

Quote from: Spiiice
We have more than one launch on the manifest that is considered expendable, and no recovery will be attempted.

...

new [cores]!
...I'm honestly pretty surprised by that myself.

Quote from: Spiiice
This is about right. Upcoming expendable F9 launches will skip the legs 'n' fins, for example.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ZachS09 on 01/20/2017 01:32 PM
Spiiice, when you said "skip the legs 'n fins", are you saying that SpaceX will remove the legs and fins from the core, or will they leave them on the core while disarmed?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 01/20/2017 01:38 PM
Spiiice, when you said "skip the legs 'n fins", are you saying that SpaceX will remove the legs and fins from the core, or will they leave them on the core while disarmed?

Spiiice is a user on Reddit, and he was saying that expendable flights won't have legs and fins.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Johnnyhinbos on 01/20/2017 01:41 PM
If expendable then there's no need to toss away expensive legs and fins. These things are installed at the launch site, so this step would just be skipped.

HOWEVER, it's my strong hope that Block 5 (1.3? Fullest Thrust??) or FH would be available by launch time, thereby not having to go the expendable route. I think it's baked right into SpaceX's very core to not expend (<- see what I did there?)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: guckyfan on 01/20/2017 02:13 PM
If expendable then there's no need to toss away expensive legs and fins. These things are installed at the launch site, so this step would just be skipped.

HOWEVER, it's my strong hope that Block 5 (1.3? Fullest Thrust??) or FH would be available by launch time, thereby not having to go the expendable route. I think it's baked right into SpaceX's very core to not expend (<- see what I did there?)

I don't think block 5 will do much in that regard. It is more about ease of reusability. They need to do some expendable flights because FH is not yet ready for regular flight and flight rates. Which will need block 5.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Norm38 on 01/20/2017 02:58 PM
What does "NET 1H" mean?  Oh, is it 'first half'?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Robotbeat on 01/20/2017 03:03 PM
No earlier than the first half of the year. As in, this is the very earliest it could launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 01/20/2017 03:12 PM
What does "NET 1H" mean?  Oh, is it 'first half'?

Yes, first half (whether I type 1H or H1 might depend on the phase of the moon or how much coffee I've had that morning, I'm not terribly consistent).  There is a quote above where they said they were around fifth or sixth in the queue, so this should be in the next couple flights after SES-10.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Jarnis on 01/20/2017 04:57 PM
Expendables might make sense from the point of view of "we have these old-spec cores that are iffy for reuse anyway, shiny new block 5s coming next that are designed for easy reuse... and some FH launches that are late, but could fly on an expendable F9. How about we just toss a few of these old spec boosters, get some pressure off the manifest - win win. I mean, we're running low on storage space for recovered boosters anyway"
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mme on 01/20/2017 05:10 PM
If expendable then there's no need to toss away expensive legs and fins. These things are installed at the launch site, so this step would just be skipped.

HOWEVER, it's my strong hope that Block 5 (1.3? Fullest Thrust??) or FH would be available by launch time, thereby not having to go the expendable route. I think it's baked right into SpaceX's very core to not expend (<- see what I did there?)

I don't think block 5 will do much in that regard. It is more about ease of reusability. They need to do some expendable flights because FH is not yet ready for regular flight and flight rates. Which will need block 5.
I do think that there was some some loss of performance with the current "safe" COPV configuration/fuel loading procedures.  It seems to me that longer load time, warmer helium, and more COPVs would all contribute to less dense LOX as well as a slight reduction in volume.  So there should be at least a small bump in performance with Block 5 above the current configuration/procedures.

I won't be surprised if there are a couple of expendable launches but it's funny that it already ready feels "wasteful" to me.  Times are a changing. :)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 01/20/2017 11:17 PM
Expendables might make sense from the point of view of "we have these old-spec cores that are iffy for reuse anyway, shiny new block 5s coming next that are designed for easy reuse... and some FH launches that are late, but could fly on an expendable F9. How about we just toss a few of these old spec boosters, get some pressure off the manifest - win win. I mean, we're running low on storage space for recovered boosters anyway"

Interesting 'problem'...
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Johnnyhinbos on 01/22/2017 03:22 PM
If expendable then there's no need to toss away expensive legs and fins. These things are installed at the launch site, so this step would just be skipped.

HOWEVER, it's my strong hope that Block 5 (1.3? Fullest Thrust??) or FH would be available by launch time, thereby not having to go the expendable route. I think it's baked right into SpaceX's very core to not expend (<- see what I did there?)

I don't think block 5 will do much in that regard. It is more about ease of reusability. They need to do some expendable flights because FH is not yet ready for regular flight and flight rates. Which will need block 5.
My reference to higher performance of Block 5 is from Elon.
From Reddit...

"Here's Elon's discussion of Block 5 from his October 23 AMA:

*"Final Falcon 9 has a lot of minor refinements that collectively are important, but uprated thrust and improved legs are the most significant.*

*"Actually, I think the F9 boosters could be used almost indefinitely, so long as there is scheduled maintenance and careful inspections. Falcon 9 Block 5 -- the final version in the series -- is the one that has the most performance and is designed for easy reuse, so it just makes sense to focus on that long term and retire the earlier versions. Block 5 starts production in about 3 months and initial flight is in 6 to 8 months, so there isn't much point in ground testing Block 3 or 4 much beyond a few reflights."*

Essentially the same as the latest tweet (wonder if the schedule shift relates to making provisions for the future new and improved COPVs, or maybe just working through the backlog of earlier generation boosters). So the main upgrades are greater thrust, improved landing legs, and better design for reuse.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 01/22/2017 05:31 PM
Payloads this heavy just aren't meant for F9R, and block 5 is highly unlikely to change that.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Chris Bergin on 04/07/2017 01:52 PM
L2 has an updated (post NROL-76) NET of May 15. Window opens at 1920 Eastern.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 04/07/2017 01:56 PM
Guess the NROL-76 delay wasn't quite long enough for this launch to jump the queue?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: vanoord on 04/07/2017 01:59 PM
Somewhat late to bring this one forward - a longer slip for NROL-76 could change that, presumably? (the 2-week turnaround on the pad appears to be the constraint at the moment)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: M.E.T. on 04/07/2017 02:58 PM
Why are launch providers not in a position to dictate to customers that delays on the customer's side mean they get pushed down the queue? After all, this has financial implications for the launch provider. Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cscott on 04/07/2017 03:06 PM
Why are launch providers not in a position to dictate to customers that delays on the customer's side mean they get pushed down the queue? After all, this has financial implications for the launch provider. Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?
I think the reason is that the launch flow is highly pipelined, and there aren't multiples of most things.  So it's not easy to leapfrog the launch schedule for small delays, since flight X is using equipment Y for a whole week, and it would cost more than it would save to get flight X off of Y and put flight X+1 on there early. (And then flight X still has to use equipment Y for a full week sometime later, delaying flights after that one...)

I think where you do see leapfrogging happen is when the delay becomes known at a time where there's a natural gap between pipeline stages and there is storage available. (Storage at the cape is getting quite tight we hear.). The step where a stage is trucked from McGregor to the Cape seems to be one such gap.  But NROL is already at the Cape, and all indications are that the delay was caused by some payload problem discovered during integration with the F9.  So it's already taking up its pipeline stage, and it would only slow up the flow (including problem resolution) to take the payload off the rocket and move everything out of the hanger.  You might get Inmarsat launched quicker, but NROL would end up taking up even more time when it got back in line.

If SpaceX is successful in getting land-to-reflight times significantly down, necessarily including the payload integration portion of that process, then I'd think you'd see more leapfrogging.  But while the launch flow is months long with a single copy of each pipeline stage it's really hard to make short-notice swaps.

IMNSHO, I'm not an expert, have no special knowledge, etc, etc.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: meberbs on 04/07/2017 03:09 PM
Why are launch providers not in a position to dictate to customers that delays on the customer's side mean they get pushed down the queue? After all, this has financial implications for the launch provider. Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?
I don't know how the SpaceX payload processing is configured, but security issues may make it difficult to parallel process with a classified payload.

Also, this probably isn't enough notice to get Inmarsat prepped by the original NROL date.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 04/07/2017 03:11 PM
Why are launch providers not in a position to dictate to customers that delays on the customer's side mean they get pushed down the queue? After all, this has financial implications for the launch provider. Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?

For a two week delay it's not likely to be worth the trouble.  Each payload has dozens of people supporting it.  It might also be difficult to quickly switch between highly classified and unclassified payloads.  The boosters will also be set up differently, NROL-76 is RTLS and the next flight should be expendable.  Some of the more picky customers may also follow their booster through construction and testing (not sure if the current contracts allow this, but you can bet the upcoming Air Force launches will.)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mn on 04/07/2017 04:03 PM
Why are launch providers not in a position to dictate to customers that delays on the customer's side mean they get pushed down the queue? After all, this has financial implications for the launch provider. Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?
I think the reason is that the launch flow is highly pipelined, and there aren't multiples of most things.  So it's not easy to leapfrog the launch schedule for small delays, since flight X is using equipment Y for a whole week, and it would cost more than it would save to get flight X off of Y and put flight X+1 on there early. (And then flight X still has to use equipment Y for a full week sometime later, delaying flights after that one...)

I think where you do see leapfrogging happen is when the delay becomes known at a time where there's a natural gap between pipeline stages and there is storage available. (Storage at the cape is getting quite tight we hear.). The step where a stage is trucked from McGregor to the Cape seems to be one such gap.  But NROL is already at the Cape, and all indications are that the delay was caused by some payload problem discovered during integration with the F9.  So it's already taking up its pipeline stage, and it would only slow up the flow (including problem resolution) to take the payload off the rocket and move everything out of the hanger.  You might get Inmarsat launched quicker, but NROL would end up taking up even more time when it got back in line.

If SpaceX is successful in getting land-to-reflight times significantly down, necessarily including the payload integration portion of that process, then I'd think you'd see more leapfrogging.  But while the launch flow is months long with a single copy of each pipeline stage it's really hard to make short-notice swaps.

IMNSHO, I'm not an expert, have no special knowledge, etc, etc.

Can they use the integration facilities at LC-40 for parallel integration (at least up to mounting on the TEL)? Or is mounting on the TEL fairly early in the process? Or is moving from LC-40 to LC-39 not practical after some point in the prep process?

Is there any active work being done to be able to prep two rockets simultaneously? or is that a long way off?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Wolfram66 on 04/07/2017 04:41 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 04/07/2017 04:46 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

What is a F9FT-Slick config?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Wolfram66 on 04/07/2017 04:55 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

What is a F9FT-Slick config?
SLICK = Expendable - No Legs or Grid-fins
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: old_sellsword on 04/07/2017 04:57 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

What is a F9FT-Slick config?
SLICK = Expendable - No Legs or Grid-fins

Just so you're aware, people were confused because "SLC" is pronounced "Slick."
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 04/07/2017 05:12 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

Is that an official (SpaceX) term, or did you just make it up?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Aerospace Dilettante on 04/07/2017 06:24 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

Is that an official (SpaceX) term, or did you just make it up?

I figured it was burrowed from the vi't nam-era slang term for a UH-1 Huey without external weapons attached.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 04/07/2017 06:31 PM
IWIK if the F9FT-Slick configs for InmarSat even been tested at McGregor and Delivered to the Cape?

Is that an official (SpaceX) term, or did you just make it up?

I figured it was burrowed from the vi't nam-era slang term for a UH-1 Huey without external weapons attached.

Yes, but let's use terms that official and/or have no chance of confusion. Otherwise we can all make up our own names for things, like "F9 Avocado".  ;)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 04/07/2017 06:41 PM
There's already a perfectly useful word for the F9 expendable configuration: expendable.  We really don't need more terms for it.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Wolfram66 on 04/07/2017 07:13 PM
There's already a perfectly useful word for the F9 expendable configuration: expendable.  We really don't need more terms for it.
Why does everyone dwell, ad nauseam, on minutia? Are the EXPENDABLE F9FT's at the cape or not? And FYI Slick comes from Aircraft terminology, meaning "Nothing Hanging", External Stores, or pylons/hardpoints. An F9 S1 can have Legs and Fins and still be expendable.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 04/07/2017 07:53 PM
There's already a perfectly useful word for the F9 expendable configuration: expendable.  We really don't need more terms for it.
Why does everyone dwell, ad nauseam, on minutia? Are the EXPENDABLE F9FT's at the cape or not? And FYI Slick comes from Aircraft terminology, meaning "Nothing Hanging", External Stores, or pylons/hardpoints. An F9 S1 can have Legs and Fins and still be expendable.

Not in any practical sense. Recovery hardware always means a recovery attempt... it's too heavy and expensive to put on otherwise.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Comga on 04/07/2017 09:40 PM
There's already a perfectly useful word for the F9 expendable configuration: expendable.  We really don't need more terms for it.
Why does everyone dwell, ad nauseam, on minutia?
You don't come here often, do you? ;)

Quote
Are the EXPENDABLE F9FT's at the cape or not?
EchoStar 23 launched on an expendable F9. You can see the rocket (https://assets.cdn.spaceflightnow.com/wp-content/uploads/2017/03/19031345/WVWS_SpaceX-Echostar-1015-2.jpg) without legs or grid fins. 
(It looked kind of naked to me....)
It launched from the cape so it was at the cape, but what specifically are you asking?
They are not distinct rockets, just regular Falcon 9s prepared differently.

Quote
And FYI Slick comes from Aircraft terminology, meaning "Nothing Hanging", External Stores, or pylons/hardpoints. An F9 S1 can have Legs and Fins and still be expendable.
Interesting, but it would be confusing here.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: feynmanrules on 04/07/2017 10:40 PM
Quote
Does it not make business sense to say well, Inmarsat has leapfrogged you now, NROL, because you missed your booked date?

I think because of of setup times and a lack of launchpads, a late fee might make more sense.

Also remember that spacex is always pushing the envelop and being late is a common side-effect.  Trying to penalize customers for missing a date probably isn't going to go over well.   ULA could probably do that if they wanted to, but they also charge enough they shouldn't care.

Maybe if spx ever gets to a true-service business model, where rockets are going up everyday with whatever payload is ready and they have enough parallelization in their flow to allow for delays... doesn't seem to be case today.

in summary- may15th it is! (back on topic ;)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: RedLineTrain on 04/07/2017 10:49 PM
As KSC moves right two weeks, perhaps Vandenberg can move left two weeks.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 04/09/2017 12:58 AM
In the discussion of why Inmarsat can't jump left into the NROL slot, in my experience, it's almost always easier to delay scheduling than it is to advance it.  There are payload processing teams from both Boeing and Inmarsat that have to be scheduled.  With a short delay, you're essentially borrowing time from an inexhaustible source (i.e. the future).  Advancing is much trickier.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: smfarmer11 on 04/09/2017 03:46 PM
Also, this is Spacex's first NRO launch, they probably want everything to go off without a hitch so they wouldn't be willing to risk having the launch pushed further back. The NRO launch is still only one month behind its original contracted launch time, and keeping it as close as possible is better for getting potential future contracts.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Chris Bergin on 04/10/2017 03:55 PM
SpaceX Opens Media Accreditation for Inmarsat-5 F4 Mission

Media Contact: John Taylor
[email protected]

HAWTHORNE, Calif. – April 10, 2017. Media accreditation is now open for SpaceX's Inmarsat-5 F4 mission from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. The launch is targeted for no earlier than May.

SpaceX’s Falcon 9 will deliver Inmarsat-5 F4 to a geostationary transfer orbit (GTO).

Members of the media who are interested in covering the launch must fill out this media accreditation form by 5:00 p.m. EDT on Thursday, April 13.

Members of the media who are foreign nationals must also provide photocopies of their valid visa and passport to [email protected] 

Requesting accreditation is not required of media who hold current annual press credentials issued by Kennedy Space Center security, but it is appreciated for planning purposes.
                                                                                                                                       
Kennedy Space Center security, not SpaceX, decides which media are credentialed to cover launches from LC-39A. Please keep in mind simply making the request in a timely fashion does not guarantee the request will be granted. Be sure to provide all the information included on the SpaceX form.

More details on the mission and pre-launch media activities will be made available at a later date closer to launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 04/25/2017 04:11 PM
Quote
Our #GlobalXpress satellite has arrived at @SpaceX for testing & fuelling in prep for launch! #I5F4 - increasing broadband comms worldwide!

https://twitter.com/inmarsatglobal/status/856901747733925889 (https://twitter.com/inmarsatglobal/status/856901747733925889)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: NX-0 on 05/01/2017 12:27 PM
Inmarsat 5 is now PRIME.
What's the window?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/01/2017 02:49 PM
Inmarsat 5 is now PRIME.
What's the window?
Window Open: 15/23:20:46 GMT May 2017
Window Close: 16/00:10:16 GMT May 2017

Target Orbit:  SSTO
1st Stage RTLS:  No (expendable)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Steven Pietrobon on 05/02/2017 11:17 AM
Target Orbit:  SSTO

As this is a Geosynchronous bird, I think the target orbit is GTO.

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/02/2017 11:44 AM
Target Orbit:  SSTO

As this is a Geosynchronous bird, I think the target orbit is GTO.
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: M.E.T. on 05/02/2017 12:04 PM
Inmarsat 5 is now PRIME.
What's the window?
Window Open: 15/23:20:46 GMT May 2017
Window Close: 16/00:10:16 GMT May 2017

Target Orbit:  SSTO
1st Stage RTLS:  No (expendable)

Expendable!  Do people still watch such boring launches?

Follow up question, would this have been expendable on the upgraded Block 5 too?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: DreamyPickle on 05/02/2017 12:17 PM
At 6100 kg this is the heaviest Falcon 9 GTO launch so far, right?

It is quite a bit heavier than the advertised maximum for Falcon 9 v1.1. According to this link (http://www.inmarsat.com/press-release/inmarsat-appoints-spacex-future-satellite-launches/) in the header this was this initially contracted assuming it would launch on Falcon Heavy:

Quote
Under the terms of its agreement with SpaceX, Inmarsat expects to use the Falcon Heavy launch vehicle, but will retain the possibility of using a Falcon 9 as an alternative, providing further launch flexibility.

Switching a payload to the regular Falcon 9 is a first for SpaceX, right? It also seems likely that Inmarsat paid for a heavy so this will be a very profitable launch for SpaceX.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Steven Pietrobon on 05/02/2017 12:19 PM
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).

Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Johnnyhinbos on 05/02/2017 12:22 PM
I was thinking he was going extremely optimistic with Single Stage To Orbit :-)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/02/2017 12:25 PM
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).

Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)

These acronyms are uninformative when they can be interpreted more than one way.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/02/2017 12:39 PM
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).

Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)

These acronyms are uninformative when they can be interpreted more than one way.

A Super-synchronous Transfer Orbit (SSTO) has an apogee height considerably above the GEO belt, with the added implications that after the perigee height is raised to GEO altitude, and inclination lowered to near-Equatorial, additional braking burns must be performed to lower the apogee height back down to GEO altitude, circularizing the final orbit.  Not to be confused with an sSTO, or sub-synchronous transfer orbit, where the apogee altitude is considerably lower than GEO....
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Phil Stooke on 05/02/2017 12:45 PM
'Single stage to orbit' anyone?  Don't use acronyms if people can't agree on what they stand for.  Spell it out - you are not limited to 140 characters.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: schaban on 05/02/2017 01:08 PM
Will they attempt fairing recovery?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: su27k on 05/02/2017 01:21 PM
At 6100 kg this is the heaviest Falcon 9 GTO launch so far, right?

Right, and apparently it's heading to SSTO, quite an accomplishment if they can pull this off, I wonder if this would be the first F9 block 4.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: king1999 on 05/02/2017 02:24 PM
'Single stage to orbit' anyone?  Don't use acronyms if people can't agree on what they stand for.  Spell it out - you are not limited to 140 characters.

Acronyms Seriously Suck! - Elon

 ;D
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/02/2017 02:25 PM
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).

Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)

These acronyms are uninformative when they can be interpreted more than one way.

A Super-synchronous Transfer Orbit (SSTO) has an apogee height considerably above the GEO belt, with the added implications that after the perigee height is raised to GEO altitude, and inclination lowered to near-Equatorial, additional braking burns must be performed to lower the apogee height back down to GEO altitude, circularizing the final orbit.  Not to be confused with an sSTO, or sub-synchronous transfer orbit, where the apogee altitude is considerably lower than GEO....

I know what they are, the issue I have is the acronyms are the same other than one starts with a small s rather than a capital. Which people aren't always going to remember or forget to use.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/02/2017 02:38 PM
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).

Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)

These acronyms are uninformative when they can be interpreted more than one way.

A Super-synchronous Transfer Orbit (SSTO) has an apogee height considerably above the GEO belt, with the added implications that after the perigee height is raised to GEO altitude, and inclination lowered to near-Equatorial, additional braking burns must be performed to lower the apogee height back down to GEO altitude, circularizing the final orbit.  Not to be confused with an sSTO, or sub-synchronous transfer orbit, where the apogee altitude is considerably lower than GEO....

Both are non-Hohmann subsets of GTO. For clarity it's probably best to refer to them as super-sync GTO and sub-sync GTO.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/02/2017 02:39 PM
What is the source for the SSTO orbit?  Is it current and reliable?  If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/02/2017 03:10 PM
What is the source for the SSTO orbit?  Is it current and reliable?  If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.

The OP looked like they were assuming it because this launch is expendable and to make up for the delay.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/02/2017 06:09 PM
What is the source for the SSTO orbit?  Is it current and reliable?  If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.

Nothing was assumed.  SpaceX is the source, three days ago.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Herb Schaltegger on 05/02/2017 09:58 PM
What is the source for the SSTO orbit?  Is it current and reliable?  If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.

Nothing was assumed.  SpaceX is the source, three days ago.

I just did a quick scan through SpaceX.com's press releases and looked at the SpaceX twitter feed for the past couple days and didn't see anything about Inmarsat. Was there a post-launch presser yesterday that mentioned it? Do you have a link to indicate the launch is in fact super-synch GTO?

Thanks.

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rockets4life97 on 05/02/2017 10:24 PM

Nothing was assumed.  SpaceX is the source, three days ago.

I just did a quick scan through SpaceX.com's press releases and looked at the SpaceX twitter feed for the past couple days and didn't see anything about Inmarsat. Was there a post-launch presser yesterday that mentioned it? Do you have a link to indicate the launch is in fact super-synch GTO?

Thanks.

Sounds like BabaORileyUSA has an inside source. We'll find out soon enough if the source is reliable.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lar on 05/03/2017 01:58 AM
L2 might be more well suited for this
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 05/03/2017 02:46 AM
If this does end up going to a super-synchronous transfer orbit, then it will provide an interesting comparison with the Echostar 23 launch.  Echostar 23 was ~5500kg and was sent to 179km x 35903km x 22.43o (http://forum.nasaspaceflight.com/index.php?topic=41932.msg1655058#msg1655058), which works out to about GTO-1711.  Inmarsat is currently listed as 6100kg.  If they have enough performance in the F9 to get it to super-synch, this may be the first definite upgraded performance launch (there seems to be a bit of debate whether NROL-76 used upgraded thrust or not).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/03/2017 02:52 AM
If this does end up going to a super-synchronous transfer orbit, then it will provide an interesting comparison with the Echostar 23 launch.  Echostar 23 was ~5500kg and was sent to 179km x 35903km x 22.43o (http://forum.nasaspaceflight.com/index.php?topic=41932.msg1655058#msg1655058), which works out to about GTO-1711.  Inmarsat is currently listed as 6100kg.  If they have enough performance in the F9 to get it to super-synch, this may be the first definite upgraded performance launch (there seems to be a bit of debate whether NROL-76 used upgraded thrust or not).
They could have used all caps but actually meant subsynchronous GTO. PR people are surprisingly light in their handling of acronyms, and sub/super distinction is very ambiguous.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Ben the Space Brit on 05/03/2017 10:36 AM
Slips could still happen but would I be correct in saying that this indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/03/2017 11:09 AM
If this does end up going to a super-synchronous transfer orbit, then it will provide an interesting comparison with the Echostar 23 launch.  Echostar 23 was ~5500kg and was sent to 179km x 35903km x 22.43o (http://forum.nasaspaceflight.com/index.php?topic=41932.msg1655058#msg1655058), which works out to about GTO-1711.  Inmarsat is currently listed as 6100kg.  If they have enough performance in the F9 to get it to super-synch, this may be the first definite upgraded performance launch (there seems to be a bit of debate whether NROL-76 used upgraded thrust or not).
This might also depend on the desires of the customer.  If you have more performance than you need to reach a minimal GTO (GTO - 1800 for the cape, 179 x 36000 x 28o) , you can use it in two different ways.
(a) Keep the apogee at GTO, but reduce the inclination.  Here they reduced it from 28o to 22.43, saving the customer about 100 m/s to get to GEO.
(b) Increase the apogee, but keep the inclination.  With the same delta-V, they could have generated an orbit that was about 179 x 48000 x 28o (super-sync).  In the case of Echostar this would have been a very similar reduction in delta-V.

Option (b) involves more navigation (at least two burns and longer intermediate orbits) by the customer, and the satellite has to be capable of working when above GEO.  But in some cases it can be significantly less delta-V required by the launcher.   In general, (a) is better if you have only a little extra performance to use.  As performance increases, the two techniques become roughly tied at about GEO-1700 from the cape.  But for better orbits than that, the super-sync method (b)  pulls ahead.   For example, the same delta-V can give you 179 x 119,000 x 28 (for GTO-1500) or 179 x 36000 x 17.7 (for GTO-1625).

From the point of view of SpaceX, the only difference is the pointing of the second stage at the GTO injection burn.  It's at the same place and lasts the same time in either case.  So I suspect they offer the option to the customer, and the customer chooses based on the navigation required, the delta-V saved, and the capabilities of the satellite.

Here is a plot of the effectiveness of both approaches, starting from a 180x180x28o parking orbit.
(http://lscheffer.com/images/ssto.png)

EDIT: Point out that (a) is better for small changes, (b) better for large ones.  EDIT again to add plot
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ChrisGebhardt on 05/03/2017 02:47 PM
Slips could still happen but would I be correct in saying that this [45th Space Wing updating their Twitter page to show Inmarsat on 15 May] indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?

All this means at this point is that 15 May is the Range approved date and Inmarsat is the next sat up for launch.  It means nothing more than that.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Roy_H on 05/03/2017 06:10 PM
Slips could still happen but would I be correct in saying that this indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?

This should have been posted in Discussion not Updates.

SpaceX has proven several times they are capable of 2 week turn-around. Barring some snafu, I think it is highly likely they will launch on the 15th. With their latest TE there is little pad damage from launch, payload encapsulation takes place in the SPIF building so should already be done. Cores delivered and time to mate first and second stage, so that is probably done too. Not much left to do.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: feynmanrules on 05/03/2017 09:23 PM
Slips could still happen but would I be correct in saying that this indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?

NSF posting protocol on UPDATE threads is always use NET launch dates.

NET = No Earlier Than (but could be later)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Johnnyhinbos on 05/05/2017 05:36 PM
If SpaceX quietly rolled out Block 4 hardware on the NRO launch, is there any possibility of ASDS return for this mission?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/05/2017 05:38 PM
If SpaceX quietly rolled out Block 4 hardware on the NRO launch, is there any possibility of ASDS return for this mission?

No
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/05/2017 06:58 PM
If SpaceX quietly rolled out Block 4 hardware on the NRO launch, is there any possibility of ASDS return for this mission?

No

Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: old_sellsword on 05/05/2017 07:02 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/05/2017 07:05 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?

For expended to ASDS changes, not block changes. The flight profile and hazard areas are very different.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: old_sellsword on 05/05/2017 07:07 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?

For expended to ASDS changes, not block changes. The flight profile and hazard areas are very different.

Ah, thanks for the clarification. And yes, I agree we would know about it by now.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 05/05/2017 07:24 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?

No, V1.2 is block III. (first F9 was block I, v1.1 was block II) We are still waiting for the first block IV launch.
(unless I am mistaken)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: M.E.T. on 05/05/2017 07:33 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?

No, V1.2 is block III. (first F9 was block I, v1.1 was block II) We are still waiting for the first block IV launch.
(unless I am mistaken)

What is the reason for that? Remaining stock of Block III cores that needs to be used up first, or the lack of available Block IV cores? And for that matter, why not skip Block IV if Block V is already available? Or is it again a case of unused Block IV cores that need to be used up first?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: old_sellsword on 05/05/2017 07:34 PM
Some things like FAA and FCC licenses would have to be modified, in addition to the launch vehicle. I believe we would have seen the FCC license by now.

That's not true. The FAA licenses issued recently still call this vehicle "Falcon 9 v1.2" even though there have been three Block upgrades since v1.2 first flew.

What makes the fourth and fifth Block upgrades so special they need a new license?

No, V1.2 is block III. (first F9 was block I, v1.1 was block II) We are still waiting for the first block IV launch.

That's how we assume Blocks work. They're definitely not (https://www.reddit.com/r/spaceflight/comments/62hfm2/spacex_on_twitter_falcon_9_first_stage_has_landed/dfna37n) as simple as that.

Quote from: Foximus05 (ex-employee)
Correction. [SES-10] was a block 1 (crs8) and wont fly again. Block 3 boosters could have multiple flights before being retired.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/05/2017 07:34 PM
No, V1.2 is block III. (first F9 was block I, v1.1 was block II) We are still waiting for the first block IV launch.
(unless I am mistaken)

Its maddening that this isn't correct, but its not. What we now know (highly suspect I guess) from various inside sources is that the blocks I,II and III we've all be referring to are different revisions of v1.2.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 05/05/2017 07:35 PM
What is the reason for that? Remaining stock of Block III cores that needs to be used up first, or the lack of available Block IV cores? And for that matter, why not skip Block IV if Block V is already available? Or is it again a case of unused Block IV cores that need to be used up first?

Production pipeline. And block V is not already available, it is said to be ready at the end of this year.


No, V1.2 is block III. (first F9 was block I, v1.1 was block II) We are still waiting for the first block IV launch.
(unless I am mistaken)

Its maddening that this isn't correct, but its not. What we now know (highly suspect I guess) from various inside sources is that the blocks I,II and III we've all be referring to are different revisions of v1.2.

Ugh.  :) Yes maddening, I stand corrected.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Herb Schaltegger on 05/05/2017 09:38 PM
The current FCC launch licenses for Florida extend into 2019 ... If regulators consider Block 4 and eventually 5 to be significant, there will probably be amendments to those licenses.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/08/2017 07:11 PM
Space Intel Report: Inmarsat reports Boeing-caused jump in US government revenue (https://www.spaceintelreport.com/inmarsat-reports-boeingcaused-jump-in-us-government-revenue)
Quote
With less than two weeks before the launch, Pearce still declined to commit to a permanent location for the fourth GX satellite but said it would operate first over Europe, the Middle East and Africa.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/09/2017 02:40 PM
Quote
DYK it takes 4 days to load the 2437kg of propellant mass needed to raise our #I5F4 satellite into orbit? Getting launch-ready at @SpaceX!

https://twitter.com/inmarsatglobal/status/861912275334172673 (https://twitter.com/inmarsatglobal/status/861912275334172673)

So roughly 40% of the mass is prop... (2437/6100)... Interesting...  ???  8)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/09/2017 03:27 PM
Quote
DYK it takes 4 days to load the 2437kg of propellant mass needed to raise our #I5F4 satellite into orbit? Getting launch-ready at @SpaceX!

https://twitter.com/inmarsatglobal/status/861912275334172673 (https://twitter.com/inmarsatglobal/status/861912275334172673)

So roughly 40% of the mass is prop... (2437/6100)... Interesting...  ???  8)
That does not seem like enough.  6100-2437 = 3663 kg.  So burning all propellant at an ISP of 320 implies a total delta-V of 320*9.8*ln(6100/3663) = 1600 m/s.   Assuming the same F9 performance as EchoStar, that's not enough to get into GEO (the lighter Echostar 23 had more than this to go to reach GEO),  much less do any stationkeeping.

So either this is a more powerful F9, or they will need to do final orbit raising electrically.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Craig_VG on 05/09/2017 04:20 PM
That does not seem like enough.  6100-2437 = 3663 kg.  So burning all propellant at an ISP of 320 implies a total delta-V of 320*9.8*ln(6100/3663) = 1600 m/s.   Assuming the same F9 performance as EchoStar, that's not enough to get into GEO (the lighter Echostar 23 had more than this to go to reach GEO),  much less do any stationkeeping.

So either this is a more powerful F9, or they will need to do final orbit raising electrically.

Well if they are doing a Super-Synchronous GTO and or reducing inclination they could possibly get it down to 1600, right? Also I think the total mass is actually more like 6070kg.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/09/2017 04:23 PM
Quote
Stephen C. Smith‏ @SpaceKSCBlog 4m4 minutes ago

I spy with my @SpaceX eye ...

https://twitter.com/SpaceKSCBlog/status/861977037107494915 (https://twitter.com/SpaceKSCBlog/status/861977037107494915)
Likely headed in for mating to 1st and 2nd stages ahead of Thursday's static fire? Should we expect to see it reemerge carrying its rocket sometime tomorrow?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: KaiFarrimond on 05/09/2017 04:48 PM
Quote
Stephen C. Smith‏ @SpaceKSCBlog 4m4 minutes ago

I spy with my @SpaceX eye ...

https://twitter.com/SpaceKSCBlog/status/861977037107494915 (https://twitter.com/SpaceKSCBlog/status/861977037107494915)
Likely headed in for mating to 1st and 2nd stages ahead of Thursday's static fire? Should we expect to see it reemerge carrying its rocket sometime tomorrow?

Most likely the day later. Depends on what time the Static Fire is though :)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/09/2017 04:49 PM
Quote
DYK it takes 4 days to load the 2437kg of propellant mass needed to raise our #I5F4 satellite into orbit? Getting launch-ready at @SpaceX!

https://twitter.com/inmarsatglobal/status/861912275334172673 (https://twitter.com/inmarsatglobal/status/861912275334172673)

So roughly 40% of the mass is prop... (2437/6100)... Interesting...  ???  8)
That does not seem like enough.  6100-2437 = 3663 kg.  So burning all propellant at an ISP of 320 implies a total delta-V of 320*9.8*ln(6100/3663) = 1600 m/s.   Assuming the same F9 performance as EchoStar, that's not enough to get into GEO (the lighter Echostar 23 had more than this to go to reach GEO),  much less do any stationkeeping.

So either this is a more powerful F9, or they will need to do final orbit raising electrically.

http://www.boeing.com/resources/boeingdotcom/space/boeing_satellite_family/pdf/Bkgd_Inmarsat-5.pdf (http://www.boeing.com/resources/boeingdotcom/space/boeing_satellite_family/pdf/Bkgd_Inmarsat-5.pdf)
IF I read the above right... this is an all electric bird...  ???
That may be 2437kg of Xenon...  :o
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Ben the Space Brit on 05/09/2017 04:55 PM
IF I read the above right... this is an all electric bird...  ???
That may be 2437kg of Xenon...  :o

That would be more than 2x Dawn's MPS prop load or, if you prefer, enough to send Immarsat 5 F4 to Saturn.  :o
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/09/2017 05:09 PM
http://www.boeing.com/resources/boeingdotcom/space/boeing_satellite_family/pdf/Bkgd_Inmarsat-5.pdf (http://www.boeing.com/resources/boeingdotcom/space/boeing_satellite_family/pdf/Bkgd_Inmarsat-5.pdf)
IF I read the above right... this is an all electric bird...  ???
That may be 2437kg of Xenon...  :o

It has a conventional apogee engine for the initial orbit raising and electric propulsion for the final orbit adjustments and stationkeeping.

I found this link on Gunter's site.  I can't find a comparable page on the current Boeing web site.
Inmarsat 5 (https://web.archive.org/web/20140806183315/http://www.boeing.com/boeing/defense-space/space/bss/factsheets/702/Inmarsat-5/Inmarsat-5.page?)
Quote
PROPULSION
Liquid apogee engine    445 N
Stationkeeping Thrusters    Xenon ion propulsion
Control Thrusters    4 x 22N (Axial)     4 x 10N (radial)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/09/2017 05:47 PM
That does not seem like enough.  6100-2437 = 3663 kg.  So burning all propellant at an ISP of 320 implies a total delta-V of 320*9.8*ln(6100/3663) = 1600 m/s.   Assuming the same F9 performance as EchoStar, that's not enough to get into GEO (the lighter Echostar 23 had more than this to go to reach GEO),  much less do any stationkeeping.

So either this is a more powerful F9, or they will need to do final orbit raising electrically.

Well if they are doing a Super-Synchronous GTO and or reducing inclination they could possibly get it down to 1600, right? Also I think the total mass is actually more like 6070kg.
To get to a GEO-1600 orbit from the cape, you need about +350 m/s over a minimal transfer orbit.  The EchoStar 23, about 500 kg lighter, only made it to +200 m/s over minimal GTO.  Raising the mass to 6070 kg would only leave about +20 m/s over minimal GTO.

On the other hand, one of the advantages of the SSTO, compared to inclination reduction, is that it lends itself to minimum residual shutdown.  This is because for SSTO you just blast as much as you can in the direction of the orbit, whereas inclination reduction wants a burn of specific direction and delta-V.  This can be a big deal since the last bit of propellant gives a lot of delta-V.  If we assume the residual fuel is on the order of 1%, or about 1,150 kg, and the stage 4500 kg, and the satellite 6070 kg, then this last percent of fuel would give about 348*9.8*ln((1150+4500+6070)/(4500+6070)) or about 350 m/s more - just about what is needed.

So that's my new prediction - a super-synchronous transfer orbit, with a minimum residual shutdown, and a final deficit of 1600 m/s.  So an inclination of 25-28 degrees, and an apogee of at least 65000 km.

Edit: add apogee and inclination predictions.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/09/2017 06:12 PM
That does not seem like enough.  6100-2437 = 3663 kg.  So burning all propellant at an ISP of 320 implies a total delta-V of 320*9.8*ln(6100/3663) = 1600 m/s.   Assuming the same F9 performance as EchoStar, that's not enough to get into GEO (the lighter Echostar 23 had more than this to go to reach GEO),  much less do any stationkeeping.

So either this is a more powerful F9, or they will need to do final orbit raising electrically.

Well if they are doing a Super-Synchronous GTO and or reducing inclination they could possibly get it down to 1600, right? Also I think the total mass is actually more like 6070kg.
To get to a GEO-1600 orbit from the cape, you need about +350 m/s over a minimal transfer orbit.  The EchoStar 23, about 500 kg lighter, only made it to +200 m/s over minimal GTO.  Raising the mass to 6070 kg would only leave about +20 m/s over minimal GTO.

On the other hand, one of the advantages of the SSTO, compared to inclination reduction, is that it lends itself to minimum residual shutdown.  This is because for SSTO you just blast as much as you can in the direction of the orbit, whereas inclination reduction wants a burn of specific direction and delta-V.  This can be a big deal since the last bit of propellant gives a lot of delta-V.  If we assume the residual fuel is on the order of 1%, or about 1,150 kg, and the stage 4500 kg, and the satellite 6070 kg, then this last percent of fuel would give about 348*9.8*ln((1150+4500+6070)/(4500+6070)) or about 350 m/s more - just about what is needed.

So that's my new prediction - a super-synchronous transfer orbit, with a minimum residual shutdown, and a final deficit of 1600 m/s.  So an inclination of 25-28 degrees, and an apogee of at least 65000 km.

Edit: add apogee and inclination predictions.

Apogee Height:  63,520 km; Inclination = 24.6 degrees.

That's not a guess, and not a calculation (that *I* did, anyways!)

Kudos to LouSheffer - you Devil, you!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/09/2017 06:45 PM
I had guessed it would be a burn-to-depletion scenario... but wow, well done @LouScheffer!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/11/2017 10:51 AM
Article for the firing and forward manifest, by Chris Gebhardt:
https://www.nasaspaceflight.com/2017/05/falcon-9-static-fire-1-inmarsat5f4/

Great article as always, thank you.

One possible omission? SpaceX did a 14 day turnaround at LC-40 in Sep 2014 (AsiaSat 6 on the 7th and CRS-4 on the 21st).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Chris Bergin on 05/11/2017 10:58 AM
Article for the firing and forward manifest, by Chris Gebhardt:
https://www.nasaspaceflight.com/2017/05/falcon-9-static-fire-1-inmarsat5f4/

Great article as always, thank you.

One possible omission? SpaceX did a 14 day turnaround at LC-40 in Sep 2014 (AsiaSat 6 on the 7th and CRS-4 on the 21st).

I just pictured you typing that with one hand whilst holding a very long spreadsheet printout was in the other hand. ;D (as a compliment). Let me see if I can add that without messing up his article ;)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ChrisGebhardt on 05/11/2017 03:10 PM
Article for the firing and forward manifest, by Chris Gebhardt:
https://www.nasaspaceflight.com/2017/05/falcon-9-static-fire-1-inmarsat5f4/

Great article as always, thank you.

One possible omission? SpaceX did a 14 day turnaround at LC-40 in Sep 2014 (AsiaSat 6 on the 7th and CRS-4 on the 21st).

Oh, totally forgot about that!  Thanks for catching that.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: getitdoneinspace on 05/11/2017 04:50 PM
STATIC FIRE! SpaceX Falcon 9 (Inmarsat 5 F4) has fired up at 39A. Wait for SpaceX tweet (after test data review).

RIGHT ON TIME. I like that. Hopefully a consistent trend while progressing through the increasing launch cadence.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: MattMason on 05/11/2017 05:07 PM
With all this successful work on 39A, you'd wonder when they'll find time to get the RSS dismantled and CC work applied. I'm sure the answer involves getting SLC 40 online by August, but their flight schedule's pretty aggressive with two active pads.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mme on 05/11/2017 05:23 PM
With all this successful work on 39A, you'd wonder when they'll find time to get the RSS dismantled and CC work applied. I'm sure the answer involves getting SLC 40 online by August, but their flight schedule's pretty aggressive with two active pads.
My understanding is that there is no rush to dismantle RSS and it does not interfere with CC work nor even CC missions.

I think they said they are going to mount the CC access arm while making the FH modifications later this year. But I could be misremembering and I'm not sure they even need the access arm for the first CC demo mission.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rockets4life97 on 05/11/2017 05:35 PM
What I am most impressed by is the schedule fidelity. It seems like SpaceX is coming in on time. They really need to do this regularly to get through the manifest.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/11/2017 05:46 PM
What I am most impressed by is the schedule fidelity. It seems like SpaceX is coming in on time. They really need to do this regularly to get through the manifest.
Nah, my reading is a launch every two weeks is already less than they can accomplish, time to move to a launch every 10 days (when the range allows for it) and see them always be a day or two behind schedule but beating the a launch every 2 weeks current plan.
But, just perhaps, that will create problems with the range that needs to be prepared for their plans.
It will be interesting anyhow.
Maybe increase the tempo by 24 hrs at a time until they find their sustainable limits.

Or maybe this looked easy because they prepared this booster in parallel with NROL-76 during the 2 week delay.

AKA I really don't know but I would love to know the answer !
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/11/2017 06:06 PM
The RSS (I admit) is an ugly eyesore and reminder for what once was...  ???

BUT...

I seems it's not in the way and for all practical purposes could be left as is... if need be...  ;)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/11/2017 06:19 PM
According to this (https://spaceflightnow.com/2017/05/10/satellite-for-broadband-on-the-go-next-in-rapid-fire-spacex-launch-campaign/), the payload adapter that Falcon 9 has is made by RUAG. This is talking about the actual PAF (https://i.imgur.com/EDpYswB.png), or a separate adapter?

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Flying Beaver on 05/11/2017 06:24 PM
According to this (https://spaceflightnow.com/2017/05/10/satellite-for-broadband-on-the-go-next-in-rapid-fire-spacex-launch-campaign/), the payload adapter that Falcon 9 has is made by RUAG. This is talking about the actual PAF (https://i.imgur.com/EDpYswB.png), or a separate adapter?

Referencing this component i'm sure.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/11/2017 06:28 PM
That was my thought too. Here is the satellite, sitting on the heavy SpaceX PAF variant (the one that is good for ten tons).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/11/2017 06:40 PM
What I am most impressed by is the schedule fidelity. It seems like SpaceX is coming in on time. They really need to do this regularly to get through the manifest.
Nah, my reading is a launch every two weeks is already less than they can accomplish, time to move to a launch every 10 days (when the range allows for it) and see them always be a day or two behind schedule but beating the a launch every 2 weeks current plan.
But, just perhaps, that will create problems with the range that needs to be prepared for their plans.
It will be interesting anyhow.
Maybe increase the tempo by 24 hrs at a time until they find their sustainable limits.

Or maybe this looked easy because they prepared this booster in parallel with NROL-76 during the 2 week delay.

AKA I really don't know but I would love to know the answer !

This bi-weekly tempo from one (relatively new) pad seems to be an achievement of the new TEL design with throwback feature.  Good news is that a similar system is coming on line at LC-40 soon.  TEL hardware of this design is probably also planned for Boca Chica and Vandenberg as schedule allows.  Four pads with quick turn-around capability removes a key constraint on launch cadence.  Likewise, reusable boosters with shorter and shorter refurb times removes the factory throughput constraint.  Finally, SpaceX will remove the static fire requirement at some point which will make weekly launches from a given pad possible.

When launching the constellation in 2019-2020, they'll need 50-100 launches a year just for internal payloads... plus another 25-50 for USG plus commercial customers.  Doesn't seem so impossible any more.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/11/2017 06:41 PM
That was my thought too. Here is the satellite, sitting on the heavy SpaceX PAF variant.

Is the payload adaptor carbon composite, too? 
Does anyone else do that?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 05/11/2017 06:52 PM
This bi-weekly tempo from one (relatively new) pad seems to be an achievement of the new TEL design with throwback feature.  Good news is that a similar system is coming on line at LC-40 soon.  TEL hardware of this design is probably also planned for Boca Chica and Vandenberg as schedule allows.  Four pads with quick turn-around capability removes a key constraint on launch cadence.  Likewise, reusable boosters with shorter and shorter refurb times removes the factory throughput constraint.  Finally, SpaceX will remove the static fire requirement at some point which will make weekly launches from a given pad possible.
Don't forget that they also now have a hangar (at 39A) that allows them to process multiple vehicles at a time.  Unfortunately, that won't translate to SLC-40 when it is back online.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/11/2017 07:31 PM
This bi-weekly tempo from one (relatively new) pad seems to be an achievement of the new TEL design with throwback feature.  Good news is that a similar system is coming on line at LC-40 soon.  TEL hardware of this design is probably also planned for Boca Chica and Vandenberg as schedule allows.  Four pads with quick turn-around capability removes a key constraint on launch cadence.  Likewise, reusable boosters with shorter and shorter refurb times removes the factory throughput constraint.  Finally, SpaceX will remove the static fire requirement at some point which will make weekly launches from a given pad possible.
Don't forget that they also now have a hangar (at 39A) that allows them to process multiple vehicles at a time.  Unfortunately, that won't translate to SLC-40 when it is back online.

Right.
There is the new refurb facility coming on line at the Port, though, which should help with the bigger rework tasks.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: spacenut on 05/12/2017 01:27 AM
Is this launch going to be webcast?  If so, when? 
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: DatUser14 on 05/12/2017 01:35 AM
Is this launch going to be webcast?  If so, when?
It should, webcast usually starts at T-20 so at 19:00 EDT
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/12/2017 03:20 AM
It seems Inmarsat isn't yet sure what it's going to do with this satellite ...

http://spacenews.com/inmarsat-undecided-on-how-it-will-use-the-satellite-spacex-is-launching-next-week/ (http://spacenews.com/inmarsat-undecided-on-how-it-will-use-the-satellite-spacex-is-launching-next-week/)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Skyrocket on 05/12/2017 09:11 AM
Interesting - the launch poster shows a F9 with legs and fins. Artistic license?

https://twitter.com/InmarsatGlobal/status/862953036683108352/photo/1
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Beittil on 05/12/2017 09:23 AM
Probably because there is not a whole lot of design material left (anymore) of Falcon 9 without legs and fins :)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: tvg98 on 05/12/2017 12:06 PM
Not sure of this has been discussed yet, but it seems that the apogee will be at around 35,786 km. Considering this is SpaceX's largest payload to GTO yet, it will be interesting to see how close it can get to that target, and how that compares to Echostar-23.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/12/2017 12:11 PM
Just posted some nice encapsulation (and thus fairing) shots by Inmarsat:

Quote
Inmarsat‏Verified account @InmarsatGlobal 23m23 minutes ago

@Boeing & Inmarsat satellite teams say goodbye to #I5F4 as it’s encapsulated into the payload fairing in prep for @SpaceX launch on 15 May 🚀

https://twitter.com/InmarsatGlobal/status/862994761405386753 (https://twitter.com/InmarsatGlobal/status/862994761405386753)

I couldn't see any obvious signs of fairing recovery equipment, although even if SpaceX are doing a recovery attempt on this mission the pictures may be the wrong fairing half.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Johnnyhinbos on 05/12/2017 01:14 PM
Just posted some nice encapsulation (and thus fairing) shots by Inmarsat:

Quote
Inmarsat‏Verified account @InmarsatGlobal 23m23 minutes ago

@Boeing & Inmarsat satellite teams say goodbye to #I5F4 as it’s encapsulated into the payload fairing in prep for @SpaceX launch on 15 May

https://twitter.com/InmarsatGlobal/status/862994761405386753 (https://twitter.com/InmarsatGlobal/status/862994761405386753)

I couldn't see any obvious signs of fairing recovery equipment, although even if SpaceX are doing a recovery attempt on this mission the pictures may be the wrong fairing half.
Funny, I was just going to ask how many people carefully scanned those pictures, not to look at the satellite but to check for recovery hardware. One shot does show a bit of the other half BTW.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: hrissan on 05/12/2017 08:06 PM
Just posted some nice encapsulation (and thus fairing) shots by Inmarsat:

Quote
Inmarsat‏Verified account @InmarsatGlobal 23m23 minutes ago

@Boeing & Inmarsat satellite teams say goodbye to #I5F4 as it’s encapsulated into the payload fairing in prep for @SpaceX launch on 15 May 🚀

https://twitter.com/InmarsatGlobal/status/862994761405386753 (https://twitter.com/InmarsatGlobal/status/862994761405386753)

I couldn't see any obvious signs of fairing recovery equipment, although even if SpaceX are doing a recovery attempt on this mission the pictures may be the wrong fairing half.
Or no recovery because every kg counts on this mission?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Jet Black on 05/12/2017 10:09 PM

Or no recovery because every kg counts on this mission?

or the velocities/path the farings end up in make it unsurvivable.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dao Angkan on 05/12/2017 10:39 PM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/12/2017 10:43 PM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.
As usual the customer is paying for their payload to be delivered to a particular orbit. If there is any leftover performance in the tank, SpaceX can do whatever they want with it. It's sorta like sending a package FedEx. You pay for it to be delivered on a particular day. What route they take to get it there and what else they do along the way is irrelevant to what you paid for so long as it gets where it's supposed to by the time it is supposed to.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: RDMM2081 on 05/13/2017 12:44 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.

Is there a concrete source for this statement that they are paying more, or just making an assumption based on the expendable launch?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dao Angkan on 05/13/2017 12:59 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.

Is there a concrete source for this statement that they are paying more, or just making an assumption based on the expendable launch?

Purely assumption. I have no insider knowledge.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: RDMM2081 on 05/13/2017 01:01 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.

Is there a concrete source for this statement that they are paying more, or just making an assumption based on the expendable launch?

Purely assumption. I have no insider knowledge.

Thanks for clarifying, I wondered if there was an article I missed about the price of the launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dao Angkan on 05/13/2017 01:09 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.

Is there a concrete source for this statement that they are paying more, or just making an assumption based on the expendable launch?

Purely assumption. I have no insider knowledge.

Thanks for clarifying, I wondered if there was an article I missed about the price of the launch.

Yes, sorry, I should have been clear that that was just my opinion.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: RDMM2081 on 05/13/2017 01:36 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.

Is there a concrete source for this statement that they are paying more, or just making an assumption based on the expendable launch?

Purely assumption. I have no insider knowledge.

Thanks for clarifying, I wondered if there was an article I missed about the price of the launch.

Yes, sorry, I should have been clear that that was just my opinion.

I think it's a reasonable assumption, and a question I would love to hear answered if anyone has a source that possibly could confirm or deny.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/13/2017 07:16 AM
I think it's a reasonable assumption, and a question I would love to hear answered if anyone has a source that possibly could confirm or deny.

I'm not so sure. We know SpaceX offer discounts for booster re-use but I've not seen any hints that SpaceX are yet reducing their prices for a new booster on the assumption that they'll get some re-use out if it. I'd be surprised if they are as the market for re-use isn't yet proven (although it's looking good). Also an expendable booster is a bit cheaper to make (legs etc aren't free).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Flying Beaver on 05/13/2017 07:26 AM
I think it's a reasonable assumption, and a question I would love to hear answered if anyone has a source that possibly could confirm or deny.

I'm not so sure. We know SpaceX offer discounts for booster re-use but I've not seen any hints that SpaceX are yet reducing their prices for a new booster on the assumption that they'll get some re-use out if it. I'd be surprised if they are as the market for re-use isn't yet proven (although it's looking good). Also an expendable booster is a bit cheaper to make (legs etc aren't free).
Hints, eh.

Inmarsat's payload is 6mt, thus they pay extra.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Barrie on 05/13/2017 08:56 AM
If the payloads being launched on F9 expendable were originally booked for FH, then I imagine they are paying somewhat less than the FH price would have been, but more than the standard F9 price.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: DOCinCT on 05/13/2017 01:33 PM
Hints, eh.
Inmarsat's payload is 6mt, thus they pay extra.
The $62M is a 2018 price for a standard launch (assume recoverable Block 5).
In 2016 USAF signed a contract for a 2018 GPS launch $82.7M; 2nd GPS launch in 2019 has a contract price of $96.5M.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: dorkmo on 05/13/2017 02:35 PM
Just posted some nice encapsulation (and thus fairing) shots by Inmarsat:

Quote
Inmarsat‏Verified account @InmarsatGlobal 23m23 minutes ago

@Boeing & Inmarsat satellite teams say goodbye to #I5F4 as it’s encapsulated into the payload fairing in prep for @SpaceX launch on 15 May 🚀

https://twitter.com/InmarsatGlobal/status/862994761405386753 (https://twitter.com/InmarsatGlobal/status/862994761405386753)

I couldn't see any obvious signs of fairing recovery equipment, although even if SpaceX are doing a recovery attempt on this mission the pictures may be the wrong fairing half.

i think that the recovery half has been on the the half with the male latches. And i think this shows the female latches.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: OnWithTheShow on 05/13/2017 05:19 PM
I would think that since they are flying the core expendable they wouldnt add the recovery hardware to the fairing either.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/13/2017 05:43 PM
The discussion of how much Inmarsat is paying for this launch is probably pointless, cause Inmarsat likely got an extra great deal cause SpaceX couldn't deliver as originally negotiated a FH launch within contract dates.

The originally negotiated price was probably a great one, giving the customer was signing up to launch on a paper rocket at that point, and the renegotiation into an expendable F9 launch just made the deal even sweeter.

Even if we knew the exact number, it would be meaningless as a basis for other launch contracts.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mme on 05/13/2017 05:51 PM
I think it's a reasonable assumption, and a question I would love to hear answered if anyone has a source that possibly could confirm or deny.

I'm not so sure. We know SpaceX offer discounts for booster re-use but I've not seen any hints that SpaceX are yet reducing their prices for a new booster on the assumption that they'll get some re-use out if it. I'd be surprised if they are as the market for re-use isn't yet proven (although it's looking good). Also an expendable booster is a bit cheaper to make (legs etc aren't free).
Hints, eh.

Inmarsat's payload is 6mt, thus they pay extra.
I agree that in the future SpaceX will charge different rates for expendable missions and RTLS missions. I believe that at the moment SpaceX is offering a discount for flying on a flight-proven (TM) booster to accelerate adoption.

Inmarsat signed the deal years ago. They paid whatever they negotiated back then so I would not include recovery in the calculation. Plus I think it was originally suppose to fly on FH though I may be wrong.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/14/2017 06:16 AM
Looks like a KSC flyer?

Quote
Mary Whenman‏ @marywhenman 3h3 hours ago

Arrived at the hotel and the launch is being publicised #I5F4

https://twitter.com/marywhenman/status/863591945574207488 (https://twitter.com/marywhenman/status/863591945574207488)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Comga on 05/14/2017 07:37 PM
Quote
#I5F4 rolling to the pad @InmarsatGlobal

https://twitter.com/m_ladovaz/status/863740942796193792 (https://twitter.com/m_ladovaz/status/863740942796193792)

The rocket doesn't look like it's being kept horizontal.
Is it an issue of perspective?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: king1999 on 05/14/2017 08:04 PM
Quote
#I5F4 rolling to the pad @InmarsatGlobal

https://twitter.com/m_ladovaz/status/863740942796193792 (https://twitter.com/m_ladovaz/status/863740942796193792)

The rocket doesn't look like it's being kept horizontal.
Is it an issue of perspective?

I would think so. Don't think they would post a picture if there is active problem.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/14/2017 08:17 PM
Quote
#I5F4 rolling to the pad @InmarsatGlobal

https://twitter.com/m_ladovaz/status/863740942796193792 (https://twitter.com/m_ladovaz/status/863740942796193792)

The rocket doesn't look like it's being kept horizontal.
Is it an issue of perspective?
I seem to remember discussion from CRS-10 maybe that the rocket doesn't need to be kept horizontal as it goes up the hill. It can be elevated slightly if needed in order to keep the nose from hitting the ground as it makes its way up, but otherwise it isn't elevated at all to maintain a horizontal orientation while on the incline. It can handle the slight negative loads that occur from being pointed downhill slightly.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 05/14/2017 08:52 PM
Quote
#I5F4 rolling to the pad @InmarsatGlobal

https://twitter.com/m_ladovaz/status/863740942796193792 (https://twitter.com/m_ladovaz/status/863740942796193792)

The rocket doesn't look like it's being kept horizontal.
Is it an issue of perspective?
I seem to remember discussion from CRS-10 maybe that the rocket doesn't need to be kept horizontal as it goes up the hill. It can be elevated slightly if needed in order to keep the nose from hitting the ground as it makes its way up, but otherwise it isn't elevated at all to maintain a horizontal orientation while on the incline. It can handle the slight negative loads that occur from being pointed downhill slightly.
I would have thought that this might be more of an issue for the payload, especially if it has already been fueled.  But maybe not or only payload specific.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: georgegassaway on 05/14/2017 09:01 PM
I would think that since they are flying the core expendable they wouldnt add the recovery hardware to the fairing either.

Depends on whether they need 100% of the fuel onboard to get the desired orbit. If they needed only say 99.9% to do the job, then the leftover 0.1% of margin could be used for the extra mass of trying to recover one fairing half. And likely it would not even require 0.1% of the margin, since the extra mass would not be a lot (and the fairing is jettisoned shortly after staging), just  pulling a reasonably seeming number (which I think likely errs on the side of being too high) out of thin air to get the idea across.

But if they need 100% to boost it as much as they can to depletion, then that's that.

Of course if they do plan so for this one,  they would have sent one of the retrieval ships out days ago.

As well, since these are tests, they may not necessarily have had time to make changes/upgrades since the two previous flights with retrieval testing.

Reportedly the first one had some tangled lines and the 2nd one landed 4 miles off target, IIRC. Cycles of Design changes  with new hardware installed for stuff like that don't tend to happen in days or weeks.

So even if this was an RTLS or ASDS landing flight, they might not have tried fairing retrieval. They don't need to keep shooting for  a random 100% success of he original  system that clearly is in need of more work after two attempts. Soft landings yes (huge accomplishment),  but not accurate ones as they will need for the "Bouncy Castle" idea to be practical. They need to learn, figure out what to change, have the time to figure that out and make it, and install the improved version.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/15/2017 11:41 AM
Not sure of this has been discussed yet, but it seems that the apogee will be at around 35,786 km. Considering this is SpaceX's largest payload to GTO yet, it will be interesting to see how close it can get to that target, and how that compares to Echostar-23.

Yes, this was discussed.  This mission is using a super-synchronous transfer orbit, well above GEO altitude.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/15/2017 11:45 AM
Inmarsat are paying extra for expendable ... surely that means that SpaceX can't take the piss and add extra weight just to see what happens ... Inmarsat are paying for all the boost they can get.
As usual the customer is paying for their payload to be delivered to a particular orbit. If there is any leftover performance in the tank, SpaceX can do whatever they want with it. It's sorta like sending a package FedEx. You pay for it to be delivered on a particular day. What route they take to get it there and what else they do along the way is irrelevant to what you paid for so long as it gets where it's supposed to by the time it is supposed to.

Not *exactly* true!  This is a minimal-residual shutdown mission.  The orbit Inmarsat is paying for is determined by the *actual* flight performance of the Falcon-9; there is no "particular orbit" in this case, just a range of possibilities.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/15/2017 01:41 PM
The Inmarsat photos appear to show that this rocket is, like the NROL 76 vehicle, using the upgraded second stage.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: manoweb on 05/15/2017 03:28 PM
And how do you determine it's a different second stage, what kind of upgrades?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: yokem55 on 05/15/2017 03:47 PM
Launch weather forecast, now 90% GO:

Quote
Launch day probability of violating launch weather constraints: 10%
Primary concern(s): Cumulus Cloud Rule

Delay day probability of violating launch weather constraints: 20%
Primary concern(s): Cumulus Cloud Rule, Liftoff Winds

That's about as good as it gets. Should be a beautiful sunset launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Space Ghost 1962 on 05/15/2017 03:52 PM
Launch weather forecast, now 90% GO:

Quote
Launch day probability of violating launch weather constraints: 10%
Primary concern(s): Cumulus Cloud Rule

Delay day probability of violating launch weather constraints: 20%
Primary concern(s): Cumulus Cloud Rule, Liftoff Winds

That's about as good as it gets. Should be a beautiful sunset launch.

Like the end of a Western - riding off into the sunset. In exactly the wrong direction.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/15/2017 04:08 PM
Launch weather forecast, now 90% GO:

Quote
Launch day probability of violating launch weather constraints: 10%
Primary concern(s): Cumulus Cloud Rule

Delay day probability of violating launch weather constraints: 20%
Primary concern(s): Cumulus Cloud Rule, Liftoff Winds

That's about as good as it gets. Should be a beautiful sunset launch.

Like the end of a Western - riding off into the sunset. In exactly the wrong direction.

Isn't local sunset at 8:06 Eastern, we are not hoping for an extended hold are we?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rpapo on 05/15/2017 04:10 PM
Isn't local sunset at 8:06 Eastern, we are not hoping for an extended hold are we?
Even without a hold, the sun angle will be low and the backscatter light in the air less.  Both of which make for good launch lighting conditions.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Space Ghost 1962 on 05/15/2017 04:10 PM
Launch weather forecast, now 90% GO:

Quote
Launch day probability of violating launch weather constraints: 10%
Primary concern(s): Cumulus Cloud Rule

Delay day probability of violating launch weather constraints: 20%
Primary concern(s): Cumulus Cloud Rule, Liftoff Winds

That's about as good as it gets. Should be a beautiful sunset launch.

Like the end of a Western - riding off into the sunset. In exactly the wrong direction.

Isn't local sunset at 8:06 Eastern, we are not hoping for an extended hold are we?

You are such a wet blanket  ;D
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: northenarc on 05/15/2017 05:48 PM
 There seems to be only one webcast as with NROL-76, guess this means separate technical webcasts have been retired. 
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Barrie on 05/15/2017 05:55 PM
There seems to be only one webcast as with NROL-76, guess this means separate technical webcasts have been retired.

Maybe viewing figures compared to the hosted webcast have been reeeeaaally low.  Anyone know?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/15/2017 06:17 PM
And how do you determine it's a different second stage, what kind of upgrades?
The exterior of this stage and the NROL 76 stage both have/had different appearances than previous stages.  One or two exterior conduits have been removed or relocated, for example.  The NROL 76 stage performed a long coast experiment before restarting, which is the expected upgrade for some future EELV missions.  There may be other, hidden improvements.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: koshvv on 05/15/2017 06:33 PM
There seems to be only one webcast as with NROL-76, guess this means separate technical webcasts have been retired.

Maybe viewing figures compared to the hosted webcast have been reeeeaaally low.  Anyone know?
You may see numbers yourself: https://www.youtube.com/user/spacexchannel/videos
Number of people watched technical webcast is 3-5 times smaller than for hosted one, but in hundreds of thousands nonetheless.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: fatdeeman on 05/15/2017 07:39 PM
There seems to be only one webcast as with NROL-76, guess this means separate technical webcasts have been retired.

Maybe viewing figures compared to the hosted webcast have been reeeeaaally low.  Anyone know?
You may see numbers yourself: https://www.youtube.com/user/spacexchannel/videos
Number of people watched technical webcast is 3-5 times smaller than for hosted one, but in hundreds of thousands nonetheless.

Perhaps it just depends on the specific launch. Last time it was a classified mission so we only had the first stage to watch anyway after a certain point and this time there is no landing to watch so perhaps they decided one feed was enough.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Jet Black on 05/15/2017 07:41 PM
There seems to be only one webcast as with NROL-76, guess this means separate technical webcasts have been retired.

Maybe viewing figures compared to the hosted webcast have been reeeeaaally low.  Anyone know?
You may see numbers yourself: https://www.youtube.com/user/spacexchannel/videos
Number of people watched technical webcast is 3-5 times smaller than for hosted one, but in hundreds of thousands nonetheless.

Perhaps it just depends on the specific launch. Last time it was a classified mission so we only had the first stage to watch anyway after a certain point and this time there is no landing to watch so perhaps they decided one feed was enough.

It could also have been for an abundance of caution in terms of giving information on speeds etc.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Michael Baylor on 05/15/2017 08:07 PM
Go Searcher remains in port. Fairing recovery attempt doesn't look likely. https://www.marinetraffic.com/en/ais/details/ships/shipid:426008/mmsi:366584000/vessel:GO%20SEARCHER
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: southshore26 on 05/15/2017 08:35 PM
Go Searcher remains in port. Fairing recovery attempt doesn't look likely. https://www.marinetraffic.com/en/ais/details/ships/shipid:426008/mmsi:366584000/vessel:GO%20SEARCHER

Marine traffic had it wrong last launch (They said it was in port... ship not in port).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: fatdeeman on 05/15/2017 11:27 PM
For a second I was hopeful they would keep showing the first stage until the feed died.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: sewebster on 05/15/2017 11:28 PM
Sounds like SpaceX people getting some good S1 views?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: wannamoonbase on 05/15/2017 11:29 PM
From the staff sounds at about 7:30 I wonder if they were watching a fairing experimental recovery.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: fatdeeman on 05/15/2017 11:29 PM
For a second I was hopeful they would keep showing the first stage until the feed died.

I get the feeling the staff are seeing some interesting stuff judging by the background noise!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: fatdeeman on 05/15/2017 11:30 PM
From the staff sounds at about 7:30 I wonder if they were watching a fairing experimental recovery.

Beat me to it!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: clegg78 on 05/15/2017 11:30 PM
I think the Spx folks were watching the S1 reentry when they were cheering.   Bummer they pulled that feed from the view early I wanted to see S1 tumble in.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: matthewkantar on 05/15/2017 11:31 PM
At around 7:10 into the launch there was a lot of noise from the crowd, think they could still see the first stage, or fairing cam streaming?

Matthew
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Firehawk153 on 05/15/2017 11:31 PM
I think the Spx folks were watching the S1 reentry when they were cheering.   Bummer they pulled that feed from the view early I wanted to see S1 tumble in.

Yep, thinking the same thing.  I bet they got some interesting views of stage 1 entry (and possibly breakup?)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: DecoLV on 05/15/2017 11:33 PM
Sounded awful. Whooooa! Ohhhhh nooooooooooo!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ZachS09 on 05/15/2017 11:33 PM
Let me tell you this: I was not watching the webcast when the crowd was moaning about the first stage LOS. I did not know what was happening at first; I thought the second stage suffered an anomaly until I heard the callout.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: TrueBlueWitt on 05/15/2017 11:35 PM
Was that the Highest S1 MECO Velocity to date?
Velocity and  Burn length compared to heaviest GTO Drone ship landing?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ZachS09 on 05/15/2017 11:37 PM
Was that the Highest S1 MECO Velocity to date?
Velocity and  Burn length compared to heaviest GTO Drone ship landing?

Are you referencing the heaviest successful GTO landing or the heaviest failed GTO landing?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: koshvv on 05/15/2017 11:37 PM
Is this Musk, twisting his fingers?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Michael Baylor on 05/15/2017 11:39 PM
Yes, that's him for sure.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: TrueBlueWitt on 05/15/2017 11:41 PM
Was that the Highest S1 MECO Velocity to date?
Velocity and  Burn length compared to heaviest GTO Drone ship landing?

Are you referencing the heaviest successful GTO landing or the heaviest failed GTO landing?

Curious about both.. How much performance margin was reserved on previous flights..
Also is there any indication that they are getting better performance either higher thrust or with moving LOX load by 10 minutes later on this flight?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: punder on 05/15/2017 11:45 PM
Yes, that's him for sure.

In his place, I'd be twisting more than my fingers. They'd have to patch a hole in the seat cushion.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: yokem55 on 05/15/2017 11:53 PM
Anyone want to take a gander at what the apogee would be if you are at 36,000km/hr with a 300 km peri?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: zubenelgenubi on 05/15/2017 11:54 PM
Seeking confirmation:
As the 2nd stage 2nd burn is apparently a burn to depletion, there will be no de-orbit burn for the 2nd stage?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rockets4life97 on 05/15/2017 11:56 PM
On time and on cadence. Looking forward to the banality of this every two weeks.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: DecoLV on 05/16/2017 12:00 AM
The payload was so heavy I was worried it would take 10 secs just to clear the tower. But it did look like a totally nominal launch.

Now we need to find that video of booster or fairings.

Arrrggh!!!!!!! // total mission success //AAAAAAAAAAAAAAARRRRRRGGGGGHHHHH!
 ;D
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Orbiter on 05/16/2017 12:07 AM
That first stage burn had a pretty impressive length to it. Looked like SECO happened at T+2:49 or so.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ulm_atms on 05/16/2017 12:07 AM
Anyone want to take a gander at what the apogee would be if you are at 36,000km/hr with a 300 km peri?

They were suppose to get super-sync if i remember right...so above 36,100.  My back of the head calc says they are close.  We'll see when satcom catalogs it.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rickl on 05/16/2017 12:09 AM
Let me tell you this: I was not watching the webcast when the crowd was moaning about the first stage LOS. I did not know what was happening at first; I thought the second stage suffered an anomaly until I heard the callout.

Yeah, the crowd noise worried me at first.  Then I realized they were probably watching the first stage.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Michael Baylor on 05/16/2017 12:12 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: lonestriker on 05/16/2017 12:14 AM
I was a little worried that they compressed the LOX loading and did it 10 minutes later than scheduled.  After AMOS-6, I'm sure they must have added sensors to help watch for problematic COPV temperatures.  I'm sure they did the late LOX load to maximize every ounce of power the F9 could give.  But that does nothing to reduce anxiety.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: JimO on 05/16/2017 12:16 AM
Seeking confirmation:
As the 2nd stage 2nd burn is apparently a burn to depletion, there will be no de-orbit burn for the 2nd stage?

Burn-to-depletion is never a good idea, one prop will run out first, and a bad mixture ratio can blow the back end off your vehicle. That fills the sky near your payload with shrapnel.

Burn-to-nominal-'empty' with controlled shutdown seems more prudent, then open the tank valves to dump leftover prop.

Question -- where would the second stage emerge into sunlight and WHO will be pre-dawn below it, and will anybody see the sunlit fuel cloud?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: zubenelgenubi on 05/16/2017 12:18 AM
What is the structure that the people with the light wands were entering (background, left) at the end of the webcast?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Michael Baylor on 05/16/2017 12:20 AM
For those wondering... https://twitter.com/RocketJoy/status/864273693395918848
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/16/2017 12:23 AM
Five launches from LC-39A in three months; three more scheduled next month.
Great to have this pad while LC-40 rebuild is happening.

Luck is what happens when preparation meets opportunity.
--Seneca
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: zubenelgenubi on 05/16/2017 12:27 AM
Seeking confirmation:
As the 2nd stage 2nd burn is apparently a burn to depletion, there will be no de-orbit burn for the 2nd stage?

Burn-to-depletion is never a good idea, one prop will run out first, and a bad mixture ration can blow the back end off your vehicle. That fills the sky near your payload with shrapnel.

Burn-to-nominal-'empty' with controlled shutdown seems more prudent, then open the tank valves to dump leftover prop.

Question -- where would the second stage emerge into sunlight and WHO will be pre-dawn below it, and will anybody see the sunlit fuel cloud?
Yes, I was too loose with the terminology--up-thread, I see Lou S referring to this as minimum residual shutdown.

Looking at a current map of the terminator, the dawn terminator is paralleling the western coast of India.  If I'm guess-timating the inclination and nodes of the transfer orbit, the stage would emerge into daylight south of the Equator, over the Indian Ocean.

Maybe observers in southeastern Africa would see a sunlit propellant dump?  Maybe Diego Garcia, or another of the remote islands in the southern Indian Ocean?

Thanks for the correction!

EDITed
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 12:30 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rickl on 05/16/2017 12:37 AM
Five launches from LC-39A in three months; three more scheduled next month.

I think it's safe to say that LC-39A has never experienced a launch cadence like this.

I remember watching the first launch from LC-39A on TV when I was a kid (Apollo 4).  I was thrilled when SpaceX signed the lease, and began to write a new chapter in the history of that storied launch site.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: FutureSpaceTourist on 05/16/2017 12:45 AM
Not sure how accurate this info is. I thought people were tweeting that the LOX load was 10 mins later than expected? Either way it seems something was different.

Quote
The LOX load came 10 minutes earlier at T-35, thanks to newer tech in Falcon 9 rockets. Both Helium and LOX are simultaneously loaded
https://twitter.com/jrourourou/status/864267217176801280 (https://twitter.com/jrourourou/status/864267217176801280)

Quote
Last year's anomaly was said to be caused by an accumulation of hyper-cooled liquid oxygen. Loading sooner decreases risk of LOX tank issues
https://twitter.com/jrourourou/status/864267816421208065 (https://twitter.com/jrourourou/status/864267816421208065)

Quote
The next two launches, #CRS11 and #BulgariaSat, will be the last two without this improved loading system.
https://twitter.com/jrourourou/status/864268612286242816 (https://twitter.com/jrourourou/status/864268612286242816)

Edit to add:

Confirmation poster got earlier and later mixed up!

Quote
I meant later; closer to liftoff. Apologies lol

https://twitter.com/jrourourou/status/864284474808389634 (https://twitter.com/jrourourou/status/864284474808389634)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: tvg98 on 05/16/2017 12:49 AM
Not sure how accurate this info is. I thought people were tweeting that the LOX load was 10 mins later than expected? Either way it seems something was different.

Quote
The LOX load came 10 minutes earlier at T-35, thanks to newer tech in Falcon 9 rockets. Both Helium and LOX are simultaneously loaded
https://twitter.com/jrourourou/status/864267217176801280 (https://twitter.com/jrourourou/status/864267217176801280)

Quote
Last year's anomaly was said to be caused by an accumulation of hyper-cooled liquid oxygen. Loading sooner decreases risk of LOX tank issues
https://twitter.com/jrourourou/status/864267816421208065 (https://twitter.com/jrourourou/status/864267816421208065)

Quote
The next two launches, #CRS11 and #BulgariaSat, will be the last two without this improved loading system.
https://twitter.com/jrourourou/status/864268612286242816 (https://twitter.com/jrourourou/status/864268612286242816)

Maybe this was the maiden flight of the long-awaited Block IV?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/16/2017 12:49 AM
Anyone want to take a gander at what the apogee would be if you are at 36,000km/hr with a 300 km peri?
Gandering away.....

Speed at shutdown looked like 36100 km/hr = 10027 m/s.  But since it was reading 0 at launch, I think this is relative to the launch site, not inertial space.  So add 408 m/s for speed of Earth rotation at the Cape.  Total 10435 m/s.

That is' the perigee speed of a 300 x 62000 km orbit.   So super synchronous, and about 1600 m/s to go, depending on the inclination.  Pretty close to what they said they were said to be targeting.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 12:51 AM
That first stage burn had a pretty impressive length to it. Looked like SECO happened at T+2:49 or so.
The press kit projected a 2 min 45 sec first stage burn, which would be the longest-ever for a v1.2 variant.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 12:56 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Iridium Next was only 8.6 tonnes of deployed payload.  Dragon CRS-8 probably exceed that by a bit.  The next Dragon may weigh more than 9 tonnes at liftoff.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/16/2017 12:59 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Iridium Next was only 8.6 tonnes of deployed payload.  Dragon CRS-8 probably exceed that by a bit.

 - Ed Kyle
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 01:00 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Iridium Next was only 8.6 tonnes of deployed payload.  Dragon CRS-8 probably exceed that by a bit.

Plus ~1 tonne for the two payload adapters on the Iridium flight to bring it to 9600 kg
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: x15_fan on 05/16/2017 01:00 AM
Not sure how accurate this info is. I thought people were tweeting that the LOX load was 10 mins later than expected? Either way it seems something was different.

Quote
The LOX load came 10 minutes earlier at T-35, thanks to newer tech in Falcon 9 rockets. Both Helium and LOX are simultaneously loaded
https://twitter.com/jrourourou/status/864267217176801280 (https://twitter.com/jrourourou/status/864267217176801280)

Quote
Last year's anomaly was said to be caused by an accumulation of hyper-cooled liquid oxygen. Loading sooner decreases risk of LOX tank issues
https://twitter.com/jrourourou/status/864267816421208065 (https://twitter.com/jrourourou/status/864267816421208065)

Quote
The next two launches, #CRS11 and #BulgariaSat, will be the last two without this improved loading system.
https://twitter.com/jrourourou/status/864268612286242816 (https://twitter.com/jrourourou/status/864268612286242816)


Insprucker said they were bringing in the LOX loading time and will continue to tune (I held by breath). The other think I noticed was a call out for "cyro-helium stir" very late into the countdown. Has anyone heard this before? Stratification mitigation in the COPVs?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 01:01 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Iridium Next was only 8.6 tonnes of deployed payload.  Dragon CRS-8 probably exceed that by a bit.

 - Ed Kyle
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
In terms of the rocket equation, it is the same as second stage dry mass, the same as the Dragon adapter mass, etc.  I keep track of deployed revenue payload mass.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: shplatt on 05/16/2017 01:10 AM
Anyone else notice the crickets at the end of the webcast, just as John was signing off?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Herb Schaltegger on 05/16/2017 01:10 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1
Iridium Next was only 8.6 tonnes of deployed payload.  Dragon CRS-8 probably exceed that by a bit.

 - Ed Kyle
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
In terms of the rocket equation, it is the same as second stage dry mass, the same as the Dragon adapter mass, etc.  I keep track of deployed revenue payload mass.

 - Ed Kyle

That's a bit disingenuous (not implying a malicious intent in the distinction, however). A satellite deployed into a sub-synchronous orbit that uses several tonnes of propellant to finalize orbit would count that mass as "deployed revenue payload mass" by your measure. The Iridium payload dispenser was, in fact, "deployed" into the target trajectory - it just remains attached to the upper stage.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 01:28 AM
So... Summary/speculation, let me see if I got this right.

- First fast-load subcooled launch since AMOS-6 LOM (perf needed for this bird)
- CRS-11 and Bulgariasat will not used fast-load subcooled, will be the final launches without it
- Includes the first fix Gwynne alluded to a while back for the COPV issue, which is apparently a later/quicker load with He and LOX loaded simultaneously, and possibly some sort of stirring procedure(?).  The second fix will be in Block 5.
- Might be a Block 4 vehicle, possibly in combination with the new S2 that Ed noticed.
- 36000 km/hour seems like an awfully round number.  Maybe not a burn to residual shutdown?

Thoughts?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 01:30 AM
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
IIRC, SpaceX built it.  I disagree with Ed that it should not be counted as payload, at least when considering established lift capability of the rocket, as a different payload could use that mass for something else.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Navier–Stokes on 05/16/2017 01:32 AM
Go Searcher remains in port. Fairing recovery attempt doesn't look likely. https://www.marinetraffic.com/en/ais/details/ships/shipid:426008/mmsi:366584000/vessel:GO%20SEARCHER

Marine traffic had it wrong last launch (They said it was in port... ship not in port).
I can confirm that Go Searcher is still docked at Port Canaveral.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/16/2017 01:38 AM
So... Summary/speculation, let me see if I got this right.

- First subcooled launch since AMOS-6 LOM (perf needed for this bird)
- CRS-11 and Bulgariasat will not used subcooled, will be the final launches without it
- Includes the first fix Gwynne alluded to a while back for the COPV issue, which is apparently a later/quicker load and possibly some sort of stirring procedure.  The second fix will be in Block 5.
- Might be a Block 4 vehicle, possibly in combination with the new S2 that Ed noticed.

Thoughts?
All the launches since AMOS-6 have used sub-cooled propellant. They just haven't used the fast load method for LOX. That was found to be part of the culprit in the AMOS-6 RUD. This rocket and all future rockets except the next two have a new design that mitigates the risk associated with fast load of LOX.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 01:39 AM
All the launches since AMOS-6 have used sub-cooled propellant. They just haven't used the fast load method for LOX. That was found to be part of the culprit in the AMOS-6 RUD. This rocket and all future rockets except the next two have a new design that mitigates the risk associated with fast load of LOX.
Ah, that's right.  The fast-load is what allows the prop to stay extra cold for better perf, but it is always subcooled.  Thanks, will fix the post.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: wannamoonbase on 05/16/2017 01:50 AM
So... Summary/speculation, let me see if I got this right.

- First fast-load subcooled launch since AMOS-6 LOM (perf needed for this bird)
- CRS-11 and Bulgariasat will not used fast-load subcooled, will be the final launches without it
- Includes the first fix Gwynne alluded to a while back for the COPV issue, which is apparently a later/quicker load with He and LOX loaded simultaneously, and possibly some sort of stirring procedure(?).  The second fix will be in Block 5.
- Might be a Block 4 vehicle, possibly in combination with the new S2 that Ed noticed.
- 36000 km/sec seems like an awfully round number.  Maybe not a burn to residual shutdown?

Thoughts?

The length of the S1 burn would seem to go against this being the up rated Block 4, higher thrust over less time. 

Maybe this was a hardware Block 4 with Block 3 thrust, incremental deployment?

A whale of a launch regardless.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 01:54 AM
Maybe this was a hardware Block 4 with Block 3 thrust, incremental deployment?
Has SpaceX ever said anything about what a "Block 4" would consist of, exactly?  We know Block 5 will have uprated thrust, just don't recall them ever saying much of anything about Block 4
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: wannamoonbase on 05/16/2017 01:59 AM
Maybe this was a hardware Block 4 with Block 3 thrust, incremental deployment?
Has SpaceX ever said anything about what a "Block 4" would consist of, exactly?  We know Block 5 will have uprated thrust, just don't recall them ever saying much of anything about Block 4

Agreed, it's not been well explained.  I believe that Block 4 is up rated thrust, COPV solution. 

Block 5 is the reuseability upgrades, new legs, heat shield etc.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ChrisC on 05/16/2017 01:59 AM
From the update thread:

Congratulations to SpaceX and Inmarsat on another successful Falcon 9 mission. This marks the 32nd overall success and the 34th Falcon 9 launch since its debut in June 2010.

I don't know what word I'd use, maybe "mission", but "launch" is a poor term.  The AMOS-6 failure occurred before launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 02:00 AM
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
IIRC, SpaceX built it.  I disagree with Ed that it should not be counted as payload, at least when considering established lift capability of the rocket, as a different payload could use that mass for something else.
You are talking about something that ULA calls "Payload Systems Weight", which is a legitimate way to record things.  For Ariane 5 it means including Sylda 5, etc.  For other launches it includes the PAF, etc.  If you are using that method for Dragon, you would also have to add Dragon's adapter, etc.  That's all fine, but I'm interested in deployed payload because that is what matters in the rocket equation. 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Robotbeat on 05/16/2017 02:06 AM
Why not count the dispenser? It's Iridium hardware. Seems to me everything forward of the Payload adapter should be considered payload even if it isn't technically deployed. It was still carried to space.
IIRC, SpaceX built it.  I disagree with Ed that it should not be counted as payload, at least when considering established lift capability of the rocket, as a different payload could use that mass for something else.
You are talking about something that ULA calls "Payload Systems Weight", which is a legitimate way to record things.  For Ariane 5 it means including Sylda 5, etc.  For other launches it includes the PAF, etc.  If you are using that method for Dragon, you would also have to add Dragon's adapter, etc.  That's all fine, but I'm interested in deployed payload because that is what matters in the rocket equation. 

 - Ed Kyle
Was the Iridium payload adapter on top of a regular payload adapter? If so, then it should be counted as payload. If it was in /place/ of the regular payload adapter, then you can count it as Stage 2. We're talking about the maximum payload mass a Falcon 9 has proven it could launch, and if the former is true, then it'd be factually incorrect to assert it has proven less.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Mongo62 on 05/16/2017 02:08 AM
- 36000 km/sec seems like an awfully round number.  Maybe not a burn to residual shutdown?

It also seems like an awfully fast number. 12% of the speed of light!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 02:09 AM
You'd ideally count the custom dispenser mass minus the mass of a standard payload adapter.  The Iridium dispenser is much more massive in comparison.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/16/2017 02:14 AM
Maybe this was a hardware Block 4 with Block 3 thrust, incremental deployment?
Has SpaceX ever said anything about what a "Block 4" would consist of, exactly?  We know Block 5 will have uprated thrust, just don't recall them ever saying much of anything about Block 4

Agreed, it's not been well explained.  I believe that Block 4 is up rated thrust, COPV solution. 

Block 5 is the reuseability upgrades, new legs, heat shield etc.

COPV fix was previously said to be in block 5, along with turbopump tweaks and the reuseability stuff.  The only thing we ever heard for block 4 was uprated thrust.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 02:15 AM
There were two COPV fixes, one short term and one in Block 5.  Believe the latter was at request of NASA and maybe USAF.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/16/2017 02:25 AM
There were two COPV fixes, one short term and one in Block 5.  Believe the latter was at request of NASA and maybe USAF.
I thought the NASA request related to long-term fixes for turbo-pump cracking.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Robotbeat on 05/16/2017 02:26 AM
There were two COPV fixes, one short term and one in Block 5.  Believe the latter was at request of NASA and maybe USAF.
I thought the NASA request related to long-term fixes for turbo-pump cracking.
NASA tends to have lots of requests.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: cppetrie on 05/16/2017 02:27 AM
There were two COPV fixes, one short term and one in Block 5.  Believe the latter was at request of NASA and maybe USAF.
I thought the NASA request related to long-term fixes for turbo-pump cracking.
NASA tends to have lots of requests.
True story.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: sewebster on 05/16/2017 03:26 AM
Gabon AOS.

Libreville's not in business for this launch, I guess.

Isn't the tracking station near Libreville?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ZachS09 on 05/16/2017 04:44 AM
I think there are two different tracking stations in Gabon.

The regular Gabon station and the Libreville station. Unless they refer to Libreville as "Gabon".
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 05/16/2017 05:00 AM
A great launch! Watch out for the steamroller, it might be rounding the corner...  :)

(For those who do not get the reference, see this article: https://www.spaceintelreport.com/has-the-spacex-steamroller-finally-arrived )
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: sewebster on 05/16/2017 05:02 AM
I think there are two different tracking stations in Gabon.

The regular Gabon station and the Libreville station. Unless they refer to Libreville as "Gabon".

Don't know. There seems to be this CNES one in Nkoltang:
http://www.esa.int/spaceinimages/Images/2014/05/Libreville_tracking_station_in_Gabon
Which I think they refer to as Libreville, since it is the larger city nearby.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: manoweb on 05/16/2017 05:05 AM

It could also have been for an abundance of caution in terms of giving information on speeds etc.

Actually it's the opposite, the previous launch gave a LOT of information on the first stage, this one FULL flight profile of the second stage from takeoff to the end. I have been extracting the data with an automated script in another thread
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Pete on 05/16/2017 08:39 AM
Is it just me, or have they trimmed down the time from MECO to Second stage Ignition even further?

Yes, they did not need to give the first stage time to get out of the blast zone, but it still felt like the speediest second stage startup I've yet seen?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Ben the Space Brit on 05/16/2017 08:41 AM
The fastest MECO to SECO1 I've ever seen was so fast that you saw the Merlin VAC's exhaust plume hit the first stage and bounce off of the top dome of the LOX tank, focussed back towards the U/S by the interstage. I'm sure that it made an interesting bit of data about high-energy fluid dynamics in near-vacuum!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: input~2 on 05/16/2017 09:29 AM
AFAICT no TLE published yet
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/16/2017 09:44 AM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1

Those are LEO launches [edit: Iridium and Dragon]. For LEO, ~10 tons is not much - it's only about half of what F9 can do.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: longboard1210 on 05/16/2017 12:08 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: curtquarquesso on 05/16/2017 12:26 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

(mass of brick) * (acceleration experienced by brick being thrown by you) = (force of brick leaving your hand, pushing you and wagon forward)

F = Ma
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/16/2017 01:27 PM
SpaceX's heaviest payloads to date. All were launched in 2017.
1. Iridium Next (1-10) - LEO (9,600 kg)
2. Inmarsat-5 F4 - GTO (6,070 kg)
3. EchoStar 23 - GTO (5,600 kg)

Dont forget about the Dragon launches. Those will be right in there near #1

Those are LEO launches. For LEO, ~10 tons is not much - it's only about half of what F9 can do.


This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 01:31 PM
Was the Iridium payload adapter on top of a regular payload adapter? If so, then it should be counted as payload. If it was in /place/ of the regular payload adapter, then you can count it as Stage 2. We're talking about the maximum payload mass a Falcon 9 has proven it could launch, and if the former is true, then it'd be factually incorrect to assert it has proven less.
No, the Iridium payload adapter was the payload adapter, or at least part of the adapter.  Why count this dead weight?  If the adapter were lighter, Iridium might have been able to put another satellite on board!

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/16/2017 01:45 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

Your explanation is correct, but it does not explain why presence of S1 does not change the picture.

Naively, gas impinging on S1 results in gas cloud between S1 and S2 having higher pressure and pushing on S2 a little more than if S1 would not be there.

This does not happen because exhaust is supersonic and any changes in pressure from below the nozzle can not propagate through the gas and affect the nozzle and S2.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 01:55 PM
Was the Iridium payload adapter on top of a regular payload adapter? If so, then it should be counted as payload. If it was in /place/ of the regular payload adapter, then you can count it as Stage 2. We're talking about the maximum payload mass a Falcon 9 has proven it could launch, and if the former is true, then it'd be factually incorrect to assert it has proven less.
No, the Iridium payload adapter was the payload adapter, or at least part of the adapter.  Why count this dead weight?  If the adapter were lighter, Iridium might have been able to put another satellite on board!

 - Ed Kyle

Iridium used a pair of dispensers mounted atop the standard SpaceX PAF:
https://spaceflightnow.com/wp-content/uploads/2016/07/IRIDIUM_Test_Prep_183_KHarris.jpg
https://assets.cdn.spaceflightnow.com/wp-content/uploads/2017/02/03171820/C04EdfTUsAEiHPC-2.jpg

It's the same PAF as the one Imarsat 5 F4 used:
https://assets.cdn.spaceflightnow.com/wp-content/uploads/2017/05/10184932/C_dCn50XgAIDsvL.jpg

The dispensers don't appear to be part of the PAF at all. IMO the dispensers are non-separating payload, while the PAF is a standard part of the second stage - but it all depends how one defines payload.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 02:03 PM
- but it all depends how one defines payload.
Yes! 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 02:15 PM
No, the Iridium payload adapter was the payload adapter, or at least part of the adapter.  Why count this dead weight?  If the adapter were lighter, Iridium might have been able to put another satellite on board!
The Iridium dispenser is also the payload adapter?  I had assumed so, do you have confirmation?  Ah, thanks @envy887, it is not:
Iridium used a pair of dispensers mounted atop the standard SpaceX PAF

In any case, you're absolutely right, if the dispenser was lighter - like a payload adapter - it could have put more payload into orbit, which is exactly my point.

From https://spaceflightnow.com/2016/12/30/iridium-satellites-closed-up-for-launch-on-falcon-9-rocket/ (https://spaceflightnow.com/2016/12/30/iridium-satellites-closed-up-for-launch-on-falcon-9-rocket/):
Quote
With a full load of propellant, each satellite weighs nearly 1,900 pounds (860 kilograms), and when combined with the specially-designed multi-spacecraft mounting dispenser, the Iridium Next package will be weigh in at more than 20,000 pounds, the heaviest payload launched by SpaceX to date.
we know the dispenser is at least 460kg.

This means we know a single satellite going to the same orbit as the Iridium constellation could have massed a little over nine metric tonnes at a minimum with downrange ASDS recovery of the first stage.

To be clear; I would not count the dispenser as payload for this flight.  However, it does demonstrate payload capability for a satellite that does not require the dispenser.

Since this is all off-topic for Inmarsat 5 F4, I'll bow out at this point.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/16/2017 02:26 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?
In order for such an effect to help, it has to throw rocket exhaust back at the engine/stage bottom. The main purpose of the flame trench is precisely to protect the rocket from its own acoustic energy.
Even if the 1st stage helps at all in the initial acceleration, its not even a tiny fraction of a second, for all practical purposes the effect is insignificant !
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/16/2017 02:32 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

Your explanation is correct, but it does not explain why presence of S1 does not change the picture.

Naively, gas impinging on S1 results in gas cloud between S1 and S2 having higher pressure and pushing on S2 a little more than if S1 would not be there.

This does not happen because exhaust is supersonic and any changes in pressure from below the nozzle can not propagate through the gas and affect the nozzle and S2.

In the example it is like the bricks you throw out bounce off something and hit you. Thereby giving you a little extra impulse at the expense of getting hit with bricks.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 02:32 PM

This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.

Don't the parameters at insertion (315 km altitude, 10,025 m/s velocity) indicate a subsynchronous transfer orbit?

Isn't a supersynchronous transfer a type of GTO?

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/16/2017 02:37 PM

This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.

Don't the parameters at insertion (315 km altitude, 10,025 m/s velocity) indicate a subsynchronous transfer orbit?

 - Ed Kyle
I calculated it naively with the elliptical orbit and got almost exactly a apogee of geo sync. i.e. 35786 km above earth surface.

v=(u*(2/r-1/a))^.5
u=GM
r=perigee from center of earth
a=semimajor axis

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/16/2017 02:41 PM

This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.

Don't the parameters at insertion (315 km altitude, 10,025 m/s velocity) indicate a subsynchronous transfer orbit?
I calculated it naively with the elliptical orbit and got almost exactly a apogee of geo sync. i.e. 35786 km above earth surface.

v=(u*(2/r-1/a))^.5
u=GM
r=perigee from center of earth
a=semimajor axis
Velocity seems relative to launch site, since it's 0 at launch and not 408 m/s.  Adding this in, you get  an inertial frame speed of 10435, for a apogee of about 62000 km, or super-synchronous.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/16/2017 02:54 PM
Am I reading it wrong, or has Space-Track.org not published a TLE yet?

Seems the newest entry is still 42697, ISS Debris...
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: mn on 05/16/2017 02:58 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

(mass of brick) * (acceleration experienced by brick being thrown by you) = (force of brick leaving your hand, pushing you and wagon forward)

F = Ma

I'm not a rocket scientist so I hope i'm allowed stupid questions.

Suppose there's a wall behind the wagon and I manage to throw enough rocks to fill the space between the wagon and the wall, and I continue throwing rocks, Now i'm not just throwing rocks in a vacum, I'm essentially pushing against this 'wall of rocks' in front of me, wouldn't that give me a little bit more thrust?

Edit: never mind, I see this was already discussed before I posted, somehow missed the last page of the thread before posting.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/16/2017 03:00 PM
Am I reading it wrong, or has Space-Track.org not published a TLE yet?

Seems the newest entry is still 42697, ISS Debris...

18 SPCS is in the process of publishing Elset One to Space-track.  42698 and 42699 will be the numbers.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Crispy on 05/16/2017 03:22 PM
I'm not a rocket scientist so I hope i'm allowed stupid questions.

Suppose there's a wall behind the wagon and I manage to throw enough rocks to fill the space between the wagon and the wall, and I continue throwing rocks, Now i'm not just throwing rocks in a vacum, I'm essentially pushing against this 'wall of rocks' in front of me, wouldn't that give me a little bit more thrust?

Any forces that act on the exhaust of a rocket engine can only propagate through that exhaust as fast as the speed of sound. Because the exhaust is moving far far faster than that, nothing downstream of the nozzle can possibly affect it.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ppnl on 05/16/2017 03:26 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

(mass of brick) * (acceleration experienced by brick being thrown by you) = (force of brick leaving your hand, pushing you and wagon forward)

F = Ma

I'm not a rocket scientist so I hope i'm allowed stupid questions.

Suppose there's a wall behind the wagon and I manage to throw enough rocks to fill the space between the wagon and the wall, and I continue throwing rocks, Now i'm not just throwing rocks in a vacum, I'm essentially pushing against this 'wall of rocks' in front of me, wouldn't that give me a little bit more thrust?

Edit: never mind, I see this was already discussed before I posted, somehow missed the last page of the thread before posting.

Only if some of the rocks you threw bounced back and hit  you. And if enough of them did that to make any measurable difference it would probably be a bad thing.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Pete on 05/16/2017 03:42 PM
If the plume pushed against the 1st stage would the intial aceleration be larger than straight into vaccum?

No. A rocket engine's thrust is a result of it throwing many thousands of pounds of propellant out of the nozzle, opposite the desired direction of travel independent of whatever is behind it. Tom Mueller had a great practical example in his recent interview. A rocket engine works on the same principle as sitting in the back of the wagon, and throwing a brick out the back of it. You'll get a small impulse from throwing a brick opposite the direction you want to travel. If you could throw thousands of pounds of bricks out the back continuously, you'd move very, very quickly.

Your explanation is correct, but it does not explain why presence of S1 does not change the picture.

Naively, gas impinging on S1 results in gas cloud between S1 and S2 having higher pressure and pushing on S2 a little more than if S1 would not be there.

This does not happen because exhaust is supersonic and any changes in pressure from below the nozzle can not propagate through the gas and affect the nozzle and S2.

In the example it is like the bricks you throw out bounce off something and hit you. Thereby giving you a little extra impulse at the expense of getting hit with bricks.

If you want to be REALLY pedantic...
The presence of S1 in the exhaust stream likely *decreases* the thrust of S2 by an infinitestimal amount.
.
No, really.
Why:
Having the exhaust plume impinge on a stationary object directly behind the S2 nozzle will cause quite a large amount of gaseous matter to "accumulate" in the area, leading to a very-slightly-less-than-vacuum environment.
This will directly result in a very slightly lower engine ISP, which mean less thrust.

The decrease in thrust is likely to be very very very small, but still larger than the "air pressure" from the bouncing gas molecules hitting S1, bouncing off, and hitting S2.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ClayJar on 05/16/2017 03:47 PM
I'm not a rocket scientist so I hope i'm allowed stupid questions.

Suppose there's a wall behind the wagon and I manage to throw enough rocks to fill the space between the wagon and the wall, and I continue throwing rocks, Now i'm not just throwing rocks in a vacum, I'm essentially pushing against this 'wall of rocks' in front of me, wouldn't that give me a little bit more thrust?

If you filled up the space with rocks and you kept shoving more in, what you would have then would be analogous to pneumatic or hydraulic pushers, some types of which SpaceX uses for certain separation events.  In that case, the force results from the pressure of the fluid in the confined space being exerted over a given area.  Since the fluid does have mass and velocity, there would be some negligible thrust caused by the fluid flowing into the space, but basically all the force is from a fluid pushing against whatever it is surrounding it.

The thing about pressure in fluids exerting forces on their surroundings is that the forces are the result of the particles (atoms, molecules, whatever) in the fluid bouncing off things.  The higher the pressure in a pneumatic cylinder, the more particles will be bouncing off the piston at the end, so the more force will result.  The thing to remember, however, is that the particles have some finite speed, and if you're moving away fast enough, you can outrun them.  You only need to be moving away fast enough that as one bounces off another off another and so on like a chain of falling dominos, they can't catch up and hit you -- in other words, the force they're trying to exert on you can't move upstream faster than the speed of sound:

This does not happen because exhaust is supersonic and any changes in pressure from below the nozzle can not propagate through the gas and affect the nozzle and S2.

In order to have any effect upstream on S2, you would have to build up enough exhaust in the vacuum of space with nothing to contain it to make a bubble with enough matter and pressure to have a high enough local speed of sound to let the forces from the colliding particles catch up to the second stage that is very rapidly departing.  (Any particles that happen to bounce off S1 back toward S2 will run into the exhaust plume and never have a chance to ricochet off S2.)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/16/2017 03:48 PM
Why:
Having the exhaust plume impinge on a stationary object directly behind the S2 nozzle will cause quite a large amount of gaseous matter to "accumulate" in the area, leading to a very-slightly-less-than-vacuum environment.
This will directly result in a very slightly lower engine ISP, which mean less thrust.

The decrease in thrust is likely to be very very very small, but still larger than the "air pressure" from the bouncing gas molecules hitting S1, bouncing off, and hitting S2.

and that is because anything not completely vacuum reduces supersonic exhaust velocity which reduces thrust?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Silmfeanor on 05/16/2017 04:26 PM
From the update thread -
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Definitly Super-synchronous.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: guckyfan on 05/16/2017 04:29 PM
From the update thread -
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Definitly Super-synchronous.

Certainly. Only thing is that upper stage will stay up there for a long time.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Wolfram66 on 05/16/2017 04:32 PM
Q) WRT F9 EXP booster, We know it has no legs not does it have grid-fins, but does it still have the GN2 RCS thrusters? Are the GN2 systems more integral to F9 construction?

thanks in advance
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Shanuson on 05/16/2017 04:36 PM

This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.

Don't the parameters at insertion (315 km altitude, 10,025 m/s velocity) indicate a subsynchronous transfer orbit?
I calculated it naively with the elliptical orbit and got almost exactly a apogee of geo sync. i.e. 35786 km above earth surface.

v=(u*(2/r-1/a))^.5
u=GM
r=perigee from center of earth
a=semimajor axis
Velocity seems relative to launch site, since it's 0 at launch and not 408 m/s.  Adding this in, you get  an inertial frame speed of 10435, for a apogee of about 62000 km, or super-synchronous.

Using the posted picture in the update thread after SECO-2 we have 4 data points of R (above ground) and V:
315km - 10025m/s,
321km - 36060km/h=10017m/s
420km - 35770km/h=9936m/s
486km - 35561km/h=9878m/s

using the formular above with GM=3.98438E14 and an Earth radius of 6371km I get an average semimajor axis of about 21340+-50km or Apogee of ~ 29552km.
Adding the 408m/s to V I get an average semimajor axis of 38407+-125km or Apogee of ~ 63688km.
Do smaller errors of the first set hint that it is wrong to add 408m/s? Yet the apogee would be well below GEO strongly suggesting that the later is the better aproximation.
The question for me remains with this analysis what V really is, velocity along the flight path or relative to ground below the stage or relative to launch site?

Edit the TLEs posted show that adding 408m/s seems to be the right way to do it.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: hans_ober on 05/16/2017 04:41 PM
Pretty good performance. 70k apogee + an inclination reduction.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/16/2017 04:44 PM
From the update thread -
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Definitly Super-synchronous.

Certainly. Only thing is that upper stage will stay up there for a long time.

Not sure how long after orbit these objects were catalogued... but is there a chance that the stage could do a de-orbit burn after a long-duration delay test as done after the last payload insertion?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/16/2017 04:46 PM
Pretty good performance. 70k apogee + an inclination reduction.
This one looks to have been a hotter performer than previous Falcon 9s.  I'm becoming more convinced that this is an upgraded variant.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 04:49 PM
Pretty good performance. 70k apogee + an inclination reduction.

Excellent performance. GTO-1570.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/16/2017 04:52 PM
Pretty good performance. 70k apogee + an inclination reduction.

Excellent performance. GTO-1570.

I'm getting this from the calc. Am I putting something wrong in?

http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm (http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm)

(https://i.imgur.com/n3UXz9Z.png)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/16/2017 05:06 PM
That doesn't include the plane change of 4 degrees, does it?
Seems to only assume the launch site was at 24.5, not 28.5.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/16/2017 05:08 PM
Yes, but it still processes the inc+circ delta V needed for GSO circular. That is the point I think (how much work does the payload have to do until it gets to operational orbit).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 05:13 PM
Yes, but it still processes the inc+circ delta V needed for GSO circular. That is the point I think (how much work has the payload to do until it gets to operational orbit).
After circ the period should be 24h and the drift 0. It looks like that calc is to circ at 70k, not at GEO.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 05:14 PM
I'm getting this from the calc. Am I putting something wrong in?

http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm (http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm)

I don't know what algorithm that site is using, but I'm using this: https://www.reddit.com/r/spacex/wiki/launches/gto_performance and here is the code: https://gist.github.com/anonymous/aa3397ea848d2e2d6986804f027e286e

This is a Lou Scheffer approved method. (See https://forum.nasaspaceflight.com/index.php?topic=36954.0 from which is based). I dont trust that site, and it seems neither does he.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/16/2017 05:16 PM
Yep, I did this wrong.  :-[ Many thanks for the prompt answers..C:
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/16/2017 05:16 PM
Pretty good performance. 70k apogee + an inclination reduction.
This one looks to have been a hotter performer than previous Falcon 9s.  I'm becoming more convinced that this is an upgraded variant.

 - Ed Kyle

Possibly, but we've also probably never seen max performance from a previous Falcon 9.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/16/2017 05:21 PM
Pretty good performance. 70k apogee + an inclination reduction.
This one looks to have been a hotter performer than previous Falcon 9s.  I'm becoming more convinced that this is an upgraded variant.

 - Ed Kyle

Possibly, but we've also probably never seen max performance from a previous Falcon 9.

Not for v1.2. We have seen a depletion burn on Thaicom 6 with v1.1 (3,016kg, 295kmx90,000kmx22.5°). It was the one that USAF criticized for unacceptable residual margins at the end of the burn.

Two years later, v1.2 did an almost identical insertion with Thaicom 8 and then landed on the barge. It is a beast.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Billium on 05/16/2017 05:58 PM
So assuming that this is max performance for the F9, at least for the moment, and as noted above by others, a 6,070 KG payload to GTO-1570, does this give us a clue what the max payload would for a GTO launch? I seem to recall seeing GTO-1800 is acceptable for customers. I don't have the knowledge to either know that GTO-1800 is ok, or the math to work backwards to get the payload. I would be interested on any thoughts by those more knowledgeable than I. I also wonder what portion of commercial payloads would exceed the mass we now think F9 is capable of. It seems like a smaller portion is restricted to the competition.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 06:16 PM
So assuming that this is max performance for the F9, at least for the moment, and as noted above by others, a 6,070 KG payload to GTO-1570, does this give us a clue what the max payload would for a GTO launch? I seem to recall seeing GTO-1800 is acceptable for customers. I don't have the knowledge to either know that GTO-1800 is ok, or the math to work backwards to get the payload. I would be interested on any thoughts by those more knowledgeable than I. I also wonder what portion of commercial payloads would exceed the mass we now think F9 is capable of. It seems like a smaller portion is restricted to the competition.

The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 06:18 PM
I'm getting this from the calc. Am I putting something wrong in?

http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm (http://www.satsig.net/orbit-research/delta-v-geo-injection-calculator.htm)

I don't know what algorithm that site is using, but I'm using this: https://www.reddit.com/r/spacex/wiki/launches/gto_performance and here is the code: https://gist.github.com/anonymous/aa3397ea848d2e2d6986804f027e286e

This is a Lou Scheffer approved method. (See https://forum.nasaspaceflight.com/index.php?topic=36954.0 from which is based). I dont trust that site, and it seems neither does he.

That calculator works fine for a single elliptic transfer. But super-sync or sub-sync requires a bi-elliptic transfer, which it can't handle.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/16/2017 06:21 PM
So assuming that this is max performance for the F9, at least for the moment, and as noted above by others, a 6,070 KG payload to GTO-1570, does this give us a clue what the max payload would for a GTO launch? I seem to recall seeing GTO-1800 is acceptable for customers. I don't have the knowledge to either know that GTO-1800 is ok, or the math to work backwards to get the payload. I would be interested on any thoughts by those more knowledgeable than I. I also wonder what portion of commercial payloads would exceed the mass we now think F9 is capable of. It seems like a smaller portion is restricted to the competition.

The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

So we are still no where near the 8300kg promise land... Figures...  :-\

Ref http://www.spacex.com/falcon9 (http://www.spacex.com/falcon9)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: JBF on 05/16/2017 06:35 PM
So assuming that this is max performance for the F9, at least for the moment, and as noted above by others, a 6,070 KG payload to GTO-1570, does this give us a clue what the max payload would for a GTO launch? I seem to recall seeing GTO-1800 is acceptable for customers. I don't have the knowledge to either know that GTO-1800 is ok, or the math to work backwards to get the payload. I would be interested on any thoughts by those more knowledgeable than I. I also wonder what portion of commercial payloads would exceed the mass we now think F9 is capable of. It seems like a smaller portion is restricted to the competition.

The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

So we are still no where near the 8300kg promise land... Figures...  :-\

Ref http://www.spacex.com/falcon9 (http://www.spacex.com/falcon9)

8300 is the GTO figure.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/16/2017 06:50 PM

This was NOT a flight to GTO!  This used a super-synchronous transfer orbit.

Don't the parameters at insertion (315 km altitude, 10,025 m/s velocity) indicate a subsynchronous transfer orbit?
I calculated it naively with the elliptical orbit and got almost exactly a apogee of geo sync. i.e. 35786 km above earth surface.

v=(u*(2/r-1/a))^.5
u=GM
r=perigee from center of earth
a=semimajor axis
Velocity seems relative to launch site, since it's 0 at launch and not 408 m/s.  Adding this in, you get  an inertial frame speed of 10435, for a apogee of about 62000 km, or super-synchronous.

Using the posted picture in the update thread after SECO-2 we have 4 data points of R (above ground) and V:
315km - 10025m/s,
321km - 36060km/h=10017m/s
420km - 35770km/h=9936m/s
486km - 35561km/h=9878m/s

using the formular above with GM=3.98438E14 and an Earth radius of 6371km I get an average semimajor axis of about 21340+-50km or Apogee of ~ 29552km.
Adding the 408m/s to V I get an average semimajor axis of 38407+-125km or Apogee of ~ 63688km.
Do smaller errors of the first set hint that it is wrong to add 408m/s? Yet the apogee would be well below GEO strongly suggesting that the later is the better aproximation.
The question for me remains with this analysis what V really is, velocity along the flight path or relative to ground below the stage or relative to launch site?

Edit the TLEs posted show that adding 408m/s seems to be the right way to do it.

I find it amazing when playing with this formula that the difference of 408m/s(the earths veloicty at the cape) is enough to make a difference between GEO of 42000km and 60000 geo super sync.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 06:55 PM
The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

I'm curious, can you explain how you got there?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: TrueBlueWitt on 05/16/2017 07:02 PM
So assuming that this is max performance for the F9, at least for the moment, and as noted above by others, a 6,070 KG payload to GTO-1570, does this give us a clue what the max payload would for a GTO launch? I seem to recall seeing GTO-1800 is acceptable for customers. I don't have the knowledge to either know that GTO-1800 is ok, or the math to work backwards to get the payload. I would be interested on any thoughts by those more knowledgeable than I. I also wonder what portion of commercial payloads would exceed the mass we now think F9 is capable of. It seems like a smaller portion is restricted to the competition.

The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

So we are still no where near the 8300kg promise land... Figures...  :-\

Ref http://www.spacex.com/falcon9 (http://www.spacex.com/falcon9)

8300 is the GTO figure.

This number  is also presumably for Block 5 which has higher Merlin thrust  levels and other changes. All boosters prior to block 5, other than potential reflights,  are probably already spoken for.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/16/2017 07:11 PM
So could any falcon heavy payload be put on f9 expendable? Well up to 8.3MT at least. Is it cheaper to expend a F9 once in a while versus have to refurb 3 boosters for heavy?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/16/2017 07:12 PM
From the update thread -
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Definitly Super-synchronous.

Certainly. Only thing is that upper stage will stay up there for a long time.
Can I ask Targeteer's source, Space-Track.org is still returning No Results to Display for 42698 and 42699.

I am assuming these did not come from them.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 07:23 PM
The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

I'm curious, can you explain how you got there?

This launch was GEO-1570, or 230 m/s past GEO-1800. I just used the rocket equation to back out the initial mass that would give this payload 230 m/s less delta v: (4500 kg + 6100 kg) * e^(230 m/s / 3414 m/s) - 4500 kg = 6838 kg (I used 233 m/s the first time, it gives 6820 kg).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 07:27 PM
Can I ask Targeteer's source, Space-Track.org is still returning No Results to Display for 42698 and 42699.

I am assuming these did not come from them.

He frequently posts orbital parameters before they show up on the tracking sites. Inside source, I guess :D
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/16/2017 07:34 PM
The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

I'm curious, can you explain how you got there?
When I do this I get a different result.   The orbit they got (70000 km apogee, 24.5 inclination) requires about 377 m/s more than a minimal GTO to both raise the apogee and reduce the inclination.  (This assumes a 180km x 180km x 28 degree parking orbit.)  The payload was 6,086kg according to Inmarsat CTO.

Then assuming 111.5t of fuel, 4.5t empty stage, we get a delta v of ISP*g*ln(initial/final) = 348*9.8*ln(122.086/10.586) = 8339 m/s.

To get 357 m/s less (the remainder is the first stage delta), you need to increase the mass to 7,380 kg.  This gives 348*9.8*ln(123.38/11.88) = 7982 m/s.   So the same performance could put 7.38 tonnes into a minimal GTO (GEO-1800) from the Cape.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/16/2017 07:40 PM
The same performance would put 6820 kg to GEO-1800, assuming the stage dry mass if 4500 kg and MVac I_sp is 348 seconds.

I'm curious, can you explain how you got there?
When I do this I get a different result.   The orbit they got (70000 km apogee, 24.5 inclination) requires about 377 m/s more than a minimal GTO to both raise the apogee and reduce the inclination.  (This assumes a 180km x 180km x 28 degree parking orbit.)  The payload was 6,086kg according to Inmarsat CTO.

Then assuming 111.5t of fuel, 4.5t empty stage, we get a delta v of ISP*g*ln(initial/final) = 348*9.8*ln(122.086/10.586) = 8339 m/s.

To get 357 m/s less (the remainder is the first stage delta), you need to increase the mass to 7,380 kg.  This gives 348*9.8*ln(123.38/11.88) = 7982 m/s.   So the same performance could put 7.38 tonnes into a minimal GTO (GEO-1800) from the Cape.

Yes... I wasn't calculating the most efficient way to get a heavier payload to the minimum GTO, just to get to the same inclination and perigee with a lower apogee.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/16/2017 08:05 PM
So... Looks like changes still coming will add the needed 920 kg to get the spec'd 8300kg to GTO..
(based on the 5 postings above this one)

AND... It's assumed that the website number they quote is the GEO-1800 (GTO) standard from the cape...
Makes me wonder sometimes...  ???

Either way... the leaving of depleted S2's in these higher orbits that will take a LONG time to decay is not a practice I'm real thrilled about... personally...
I really wish they could quote GEO-1800 with one more short burn later to get the S2 down in short order...
BUT... that's just me...  :P
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/16/2017 08:21 PM
So... Looks like changes still coming will add the needed 920 kg to get the spec'd 8300kg to GTO..
(based on the 5 postings above this one)

AND... It's assumed that the website number they quote is the GEO-1800 (GTO) standard from the cape...
Makes me wonder sometimes...  ???

Either way... the leaving of depleted S2's in these higher orbits that will take a LONG time to decay is not a practice I'm real thrilled about... personally...
I really wish they could quote GEO-1800 with one more short burn later to get the S2 down in short order...
BUT... that's just me...  :P

You're mixing a whole lot of issues up.

I really, truly, seriously doubt SpaceX today is selling expendable F9 launches, period.

This was originally contracted as a FH launch, FH got delayed, SpaceX managed to substitute with a F9 expendable launch to keep the customer !

The most performance SpaceX is selling today for a F9 launch is likely the predicted ASDS recovery performance of a Block V F9.

Instead of expendable F9, they're selling FH.

But what's launching now, was likely negotiated 2 or more years ago.

Of course, there are dozens of F9 launches that have been sold a while ago that will require expendable performance. Once FH is flying, if the schedule permits, SX might try to renegotiate that into a FHR launch.

For new contracts, expendable only comes into play if FH can't handle it without expending a booster.

Ask Ariane, ULA and others what they do on their GTO launches about the upper stage, I doubt they always include extra margin for a deorbit. Its a BIG sky !

There's a very sophisticated system that predicts near misses. If you're going to be concerned, be concerned about the thousands of little pieces in orbit in LEO that the ISS has to track, those will stay there in orbit for decades.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: guckyfan on 05/16/2017 08:27 PM
SpaceX has done similar to other providers with loiter time on this flight. On lower orbits they do deorbit burns. With loiter times longer they may be able to do more in the future. It does not take much for faster deorbit. As long as the stage does not desintegrate.

Can anyone give a rough estimate how long this stage will take to deorbit? 384km altitude does mean it still experiences some drag on perigee.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 05/16/2017 08:37 PM
So could any falcon heavy payload be put on f9 expendable? Well up to 8.3MT at least. Is it cheaper to expend a F9 once in a while versus have to refurb 3 boosters for heavy?

The only things on the manifest (that we know about) that couldn't use F9 expendable are the beyond LEO Dragon flights and STP-2.  (FH will be required for some Air Force/NRO missions that SpaceX would compete for in the future.)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/16/2017 08:52 PM

Can anyone give a rough estimate how long this stage will take to deorbit? 384km altitude does mean it still experiences some drag on perigee.
The rule is that the stage should de-orbit naturally within 25 years.  According to Twenty-five Years, more or less? (https://www.researchgate.net/profile/David_Finkleman/publication/268556793_Twenty-Five_Years_More_or_Less_Interpretation_of_the_Low_Earth_Orbit_Debris_Mitigation_25_Year_Post-Mission_Lifetime_Guideline/links/569c117308ae6169e5627946/Twenty-Five-Years-More-or-Less-Interpretation-of-the-Low-Earth-Orbit-Debris-Mitigation-25-Year-Post-Mission-Lifetime-Guideline.pdf), Figure 8, this is right about at that limit.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/16/2017 09:08 PM
Would it be inconvenient in orbital mechanics to use a lower perigee orbit instead ? Just enough the 2nd stage would deorbit in less than a year.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 09:11 PM
Would it be inconvenient in orbital mechanics to use a lower perigee orbit instead ? Just enough the 2nd stage would deorbit in less than a year.

A lot of them do use a lower perigee. See: https://www.reddit.com/r/spacex/wiki/launches/gto_performance
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/16/2017 09:36 PM
Does anyone really think a burn terminated almost exactly at 36,000km/hr was a burn to minimum residuals?  Seems very unlikely.  Probably close, but still a little gas left in the tank.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Kasponaut on 05/16/2017 09:40 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.

How is that a deficit to GTO? It is almost twice as high as a standard GTO orbit.
Or am I missing something?
And what do you mean with almost Zenit/Proton performance?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Herb Schaltegger on 05/16/2017 09:43 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.

How is that a deficit to GTO? It is almost twice as high as a standard GTO orbit.
Or am I missing something?

Not the altitude of the apogee, but the velocity deficit (measured in deltaV) necessary to reach GSO at 0 degrees inclination. The usual "standard" GTO for a launch from Floria is -1,800 m/s.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/16/2017 09:58 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.

How is that a deficit to GTO? It is almost twice as high as a standard GTO orbit.
Or am I missing something?
And what do you mean with almost Zenit/Proton performance?

Its just deficit to GEO. Means 1570 m/s to circularize at GEO at 0 degrees inclination
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Space Ghost 1962 on 05/16/2017 10:01 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.
Those have more stages too. Not bad for kerolox 2 stage.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 05/16/2017 10:46 PM
Insprucker said they were bringing in the LOX loading time and will continue to tune (I held by breath). The other think I noticed was a call out for "cyro-helium stir" very late into the countdown. Has anyone heard this before? Stratification mitigation in the COPVs?
If you listen closely, I believe you'll hear that this is actually "Stage 1, Stage 2 Cryo-helium secured" and not "stir".  Which I assume just means that they have stopped loading He and closed all appropriate valves prior to launch.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: nacnud on 05/16/2017 10:53 PM
A vid of what I think is the fairing after sep. Interestingly you can see the tiles inflating over time, starts on the left and moves right. Is it getting cooked or is something else happening?

https://www.instagram.com/p/BUK6BQnBNuK/
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Space Ghost 1962 on 05/16/2017 11:04 PM
They might be swelling as moisture bakes out. Perhaps just ... warping (meniscus or potato chip).

I think they're hygroscopic?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: deruch on 05/16/2017 11:08 PM
There were a few frames of the LOX tank view right before they lost signal during the coast.  I was finally able to screencap one from Youtube by using <comma> and <period> to go frame-by-frame.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: launchwatcher on 05/16/2017 11:09 PM
A vid of what I think is the fairing after sep. Interestingly you can see the tiles inflating over time, starts on the left and moves right. Is it getting cooked or is something else happening?

https://www.instagram.com/p/BUK6BQnBNuK/

They seem to have stabilized the fairing...  compare with the roll rates in the first fairing video: https://www.youtube.com/watch?v=4_sLTe6-7SE
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: TrueBlueWitt on 05/16/2017 11:12 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.
Those have more stages too. Not bad for kerolox 2 stage.

You mean Zenit-3SL(not B)  Correct?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Space Ghost 1962 on 05/16/2017 11:20 PM
Correct. The three stage. The 2 is a two stage, the 3 is a three stage, the B/M is launched from Kazahstan, the SL is from the SeaLaunch platform near the equator.

add:

Block DM-SL third stage.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: TrueBlueWitt on 05/16/2017 11:25 PM
Correct. The three stage. The SLB/M is a two stage.

I thought the 3SL and 3SLB were basically the same.. just SL went from Equatorial(Sea Launch) and 3SLB from Baikonur (with corresponing huge dV hit to GTO).  From what I saw, 3SLB is only good for around 3750kg to GTO.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/17/2017 12:44 AM
Does anyone really think a burn terminated almost exactly at 36,000km/hr was a burn to minimum residuals?  Seems very unlikely.  Probably close, but still a little gas left in the tank.
Well, Michele Franci, the CTO of Inmarsat, really thinks so.  From Falcon 9 set to launch Inmarsat satellite for in-flight wifi, mobile broadband (https://spaceflightnow.com/2017/05/14/falcon-9-set-to-launch-inmarsat-satellite-for-in-flight-wifi-mobile-broadband/):

Quote
Parameters for the target orbit are not available, he said, because the upper stage engine is programmed to keep firing until it is almost out of fuel, a technique rocket engineers call a “minimum residual shutdown.” The tank-draining burn is intended to ensure the Inmarsat 5 F4 satellite goes into as high of an orbit as possible, reducing the work the craft’s own thrusters need to do in the coming months.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: abaddon on 05/17/2017 12:52 AM
Well, there you go :).  Nice find!  Guess it was a case of the unlikely seeming round number.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Jdeshetler on 05/17/2017 01:06 AM
There were a few frames of the LOX tank view right before they lost signal during the coast.  I was finally able to screencap one from Youtube by using <comma> and <period> to go frame-by-frame.

Cool, here is an animate gif, only 2 frames....
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/17/2017 01:13 AM
Data over in the Falcon Simulations thread definitely shows this booster was run at a higher thrust than SES-10. Altitude and velocity were both higher at every point in the boost.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/17/2017 02:07 AM
There are multiple reports of two unnamed sources stating that the last two F9 launches were Block III booster + Block IV upper stage.
So, if that's true, what would be the effect of a Block IV booster with the same thrust upgrade ?
Is it enough for another 200Kg to GTO-1800 capability ?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/17/2017 02:33 AM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km     
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.

How is that a deficit to GTO? It is almost twice as high as a standard GTO orbit.
Or am I missing something?
And what do you mean with almost Zenit/Proton performance?

Zenit 3SL running from the equator can do around 6 tons to GTO-1500. Proton M+ (enhanced) can do around 6.3 tons.

Both use 3 stages to get there (Blok D and Briz M accordingly).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Robotbeat on 05/17/2017 03:11 AM
Is Falcon 9 the highest performance two stage rocket currently flying to GTO? Or ever?

I do believe everything else has to use strap on boosters &/or multiple stages to get this performance.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/17/2017 04:35 AM
Rockets designed/converted for GTO missions tend to use a third and/or fourth stage (or LRB/SRBs). Falcon 9 has been designed differently, using an abnormally large second stage (and second stage engine).

It will be the most powerful TSTO LV for GTO missions until New Glenn flies (and assuming that the two stage NG will be used for GTO campaigns, something that is not certain - Blue have talked about an optional BE-3U third stage for high energy missions).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: guckyfan on 05/17/2017 07:11 AM
Without any calculations done. Even if not very efficient, the raw power of New Glenn should get a GEO com sat to GTO in its 2 stage configuration. Everything else would make launches quite expensive.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Steven Pietrobon on 05/17/2017 09:08 AM
Here's a higher resolution capture of Stage 2 LOX tank.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/17/2017 01:56 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km     
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GTO. That's almost Zenit-3SLB/Proton-M/Briz-M performance.

How is that a deficit to GTO? It is almost twice as high as a standard GTO orbit.
Or am I missing something?
And what do you mean with almost Zenit/Proton performance?

Zenit 3SL running from the equator can do around 6 tons to GTO-1500. Proton M+ (enhanced) can do around 6.3 tons.

Both use 3 stages to get there (Blok D and Briz M accordingly).

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: BabaORileyUSA on 05/17/2017 01:58 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GEO. That's almost Zenit-3SL/Proton-M/Briz-M performance.

Just a question about your sign convention:  how can the DEFICIT to GEO be this large, when this mission used a super-synchronous transfer orbit?  It would seem to have a significantly smaller deficit, since the semi-major axis is much closer to GEO than a standard Hohmann GTO, or indeed, even the S/C separation orbit of a Briz-M for a payload of equal mass... isn't the energy of the orbit a function of semi-major axis?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/17/2017 02:11 PM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Shanuson on 05/17/2017 02:55 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GEO. That's almost Zenit-3SL/Proton-M/Briz-M performance.

Just a question about your sign convention:  how can the DEFICIT to GEO be this large, when this mission used a super-synchronous transfer orbit?  It would seem to have a significantly smaller deficit, since the semi-major axis is much closer to GEO than a standard Hohmann GTO, or indeed, even the S/C separation orbit of a Briz-M for a payload of equal mass... isn't the energy of the orbit a function of semi-major axis?

Function of semimajor axis, but also of eccentricity
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Kaputnik on 05/17/2017 04:32 PM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

It's looking that way, but the point of the discussion was to compare F9 with other all Kerolox launchers.
It's pretty remarkable that Falcon can be within sight of a three stage vehicle using staged combustion engines.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/17/2017 04:36 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

Roughly a 1,570m/s deficit to GEO. That's almost Zenit-3SL/Proton-M/Briz-M performance.

Just a question about your sign convention:  how can the DEFICIT to GEO be this large, when this mission used a super-synchronous transfer orbit?  It would seem to have a significantly smaller deficit, since the semi-major axis is much closer to GEO than a standard Hohmann GTO, or indeed, even the S/C separation orbit of a Briz-M for a payload of equal mass... isn't the energy of the orbit a function of semi-major axis?

The most expensive orbital maneuver is the plane change, so you should look at the 24.5deg parameter. The reason for a supersynchronous injection is because the more eccentric the orbit, the cheaper it is to do the orbital plane change at apogee (because most energy is potential energy and not actual velocity). If you were on the equatorial plane already, which is the Zenit-3SL case, there would be no reason whatsoever to do a supersynchronous injection, from an energy optimization point of view. In fact, you would then have to spend more energy to reduce it to GEO altitude.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/17/2017 04:39 PM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

Sea Launch is, apparently, going to be re-purposed for another, TBD launcher. While Zenit I think still has a single launch left from Baikonour. But the comment was on the performance level, rather than the current competitors.
The EELV can easily do that, and so does Ariane 5. But on both cases they offer a range of payloads above and below. Proton and Zenit had, in their GTO configuration, a single performance level, no scaling. Now Proton might be introducing Medium variants and such. But, as with all Russian LV project, I'll believe it when it launches.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/17/2017 04:42 PM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?
Perhaps this will better explain to people how significant this performance was, considering it was also the heaviest F9 GTO payload to date !
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/17/2017 06:15 PM
Here's how I was finally able to get my mind around this launch result. 

It would take an Atlas 541 to match this performance, or a Proton M Briz M Phase 3 or 4.  Ariane 5 ECA could do it, of course, as could Delta 4 Heavy.  CZ-5, theoretically though it has yet to demonstrate the capability.  H-2B, ditto.  That's it, I think, among active launchers.

Delta 4 Mediums can't do this at all.  Neither can H-2A, or CZ-3B, or CZ-7, or GSLV Mk 3. 

When Falcon 9 first began flying, I thought of it as slightly better than Delta 2 class.  The machine has evolved, and the most recent two flights have exhibited a new level of performance - to the extent that I'm convinced we are seeing at least a Block 4 second stage.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/17/2017 07:42 PM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?
Perhaps this will better explain to people how significant this performance was, considering it was also the heaviest F9 GTO payload to date !
The problem with orbital mechanics is that mixing apogee increase AND plane change is a lot cheaper than doing one and then the other one. I will yield to Lou to do such calculation, though.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AC in NC on 05/17/2017 07:44 PM
Here's how I was finally able to get my mind around this launch result. 

It would take an Atlas 541 to match this performance, or a Proton M Briz M Phase 3 or 4.  Ariane 5 ECA could do it, of course, as could Delta 4 Heavy.  CZ-5, theoretically though it has yet to demonstrate the capability.  H-2B, ditto.  That's it, I think, among active launchers.

Delta 4 Mediums can't do this at all.  Neither can H-2A, or CZ-3B, or CZ-7, or GSLV Mk 3. 

When Falcon 9 first began flying, I thought of it as slightly better than Delta 2 class.  The machine has evolved, and the most recent two flights have exhibited a new level of performance - to the extent that I'm convinced we are seeing at least a Block 4 second stage.

 - Ed Kyle

Here's how I was finally able to get my mind around Ed's excellent explanation of this launch result.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/17/2017 08:09 PM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?

The same delta-V, no inclination reduction, would give a apogee of about 81,000 km at 28 degrees.  Interestingly, this is only a few m/s further from GEO than the orbit they got.  (The curve of remaining delta-V vs inclination removed is quite shallow).  By my calculation, they would have been slightly better off with an orbit half way between these two (78000 km apogee and 26.13 degrees, but the difference is small (9 m/s).  I suspect the difference is due to SpaceX optimizing for least delta-V remaining, assuming worst-case performance of the burn to depletion, but then having a non-worst-case burn.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: clegg78 on 05/17/2017 08:22 PM
Perhaps Chris can give away a free L2 subscription to the 1st person that can identify which of the preceeding 12 isn't like the others.

Hmm... I was going to say they all have strap on boosters (Solid or liquid) except for Proton and F9.

Is it that the Proton is a 4 stage rocket?  I don't think any of the others are.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AC in NC on 05/17/2017 08:26 PM
Perhaps Chris can give away a free L2 subscription to the 1st person that can identify which of the preceeding 12 isn't like the others.

Hmm... I was going to say they all have strap on boosters (Solid or liquid) except for Proton and F9.

Is it that the Proton is a 4 stage rocket?  I don't think any of the others are.

Oh ... I wasn't going for anything tricky ... I was considering the Proton to have protuberances as well regardless of whether they were literally a strap on booster.  Gotta be some performance bonus versus a clean stick.   8)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/17/2017 08:32 PM
Perhaps now I actually understand why people are so reluctant to even entertain the possibility that F9 expendable with zero margins might be able to put an 8.3 ton payload in GTO-1800 m/s. That would challenge every rocket in service, except for Ariane V and D4H.
It really must be hard to conceive that such a cheap rocket can get that much performance. But I'm a believer, eventually there will be one Block V expendable launch that will place something like a 7.5 ton payload to an orbit similar to this, and awe the world ! A payload large enough that in requires the same effort to put that 8.3 tons to GTO-1800 !
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/17/2017 08:48 PM
Perhaps Chris can give away a free L2 subscription to the 1st person that can identify which of the preceeding 12 isn't like the others.

Hmm... I was going to say they all have strap on boosters (Solid or liquid) except for Proton and F9.

Is it that the Proton is a 4 stage rocket?  I don't think any of the others are.

The first stage consists of a central cylindrical oxidizer tank with the same diameter as the other 2 stages, with 6 fuel tanks attached to its circumference, each carrying an engine. These side fuel tanks do not separate at MECO, the entire stage detaches as a unit from S2.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/17/2017 08:58 PM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?
Perhaps this will better explain to people how significant this performance was, considering it was also the heaviest F9 GTO payload to date !
The problem with orbital mechanics is that mixing apogee increase AND plane change is a lot cheaper than doing one and then the other one. I will yield to Lou to do such calculation, though.
I thought that the best usage of LV performance was to put the GTO payload on as high as possible apogee, and THEN once its on a super sync trajectory, it can use the lower speeds of the apogee to effect some inclination change and reduction in apogee on each orbital apogee and increase in perigee on each orbital perigee, done by the payload itself.

That led me to think that if SpaceX could create a mini ITS rocket that had perhaps 5+ days of mission endurance, it could do a bi elliptical transfer by itself, by going into a super sync orbit, doing the entire inclination change and apogee reduction in a single burn, then the perigee raising in the other half orbit and deliver a large number of GEO payloads into GEO-500m/s with zero inclination and just some circularization left, so the orbital period is a few hours away from GEO, so the payloads can pace themselves to go directly into their exact slots, although they would all be delivered to the same initial orbit.
The mini ITS would then do the required orbital transfer to re-enter and land, avoiding brute force trajectory corrections to get to the LZ.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: saliva_sweet on 05/17/2017 09:19 PM
The machine has evolved, and the most recent two flights have exhibited a new level of performance - to the extent that I'm convinced we are seeing at least a Block 4 second stage.

Not sure about two latest flights, but the last one was totally out of family. Looks like a different rocket.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/17/2017 09:22 PM
A factor to consider when talking about F9 v1.2 performance as a kerolox gas generator TSTO is the use of sub-cooled propellants. When originally introduced, SpaceX got a lot of flak for that decision (and they still are afaik when talking about CC).

During the OG2 M2 and SES-9 campaigns, SpaceX was struggling a lot to work out the bugs and streamline the GSE and launch procedures. Here is a reminder.

Falcon 9 Flight 20 - ORBCOMM-2 RTF Mission
core number: 1019
  S) 2015-12-16, Unsuccessful static fire [59]
  S) 2015-12-17, Unsuccessful static fire, deep cryo liquid oxygen presenting some challenges [59]
  F) 2015-12-18, Successful static fire [59]
  D) 2015-12-20, 24h delay for improved odds for landing attempt and better analysis for subcooled LOX (Possibly due to wind gusts that affect landing and LOX temps) [60]
  L) 2015-12-21, Successful launch (the one with the epic landing at LZ1)[61]
  BR) 2015-12-21, Successful landing at LZ1[61]
  S) 2016-01-14, Static fire scrub (ground side issues) [67]
  F) 2016-01-15, Successful static fire (engine 9 showed thrust fluctuations. Maybe some debris ingestion) [67]

Falcon 9 Flight 22 - SES-9
payload mass: 5,271 kilograms, orbit: geosynchronous, delivered orbit: 334 x 40648 km x 27.96° [65], [69]
core number: 1020
  F) 2016-02-22, Successful static fire [64]
  D) 2016-02-24, 24h delay to ensure liquid oxygen temperatures are as cold as possible in an effort to maximize performance of the vehicle (due to high winds) [66]
  C) 2016-02-25, Scrub at T-1:41, LOX loading issues [65]   R) 2016-02-28, Delay, wayward boat got into range [65]   C) 2016-02-28, Scrub at T-0, aborted on low thrust alarm. Rising oxygen temps due to hold for boat and helium bubble triggered alarm [65]
  D) 2016-03-01, Delay due to extreme high altitude wind shear [68]
  L) 2016-03-05, Successful launch (the one with the difficult landing attempt) [65]  BL) 2016-03-05, Hard landing at OCISLY (3 engine landing burn, run out of propellant, no boostback burn) [65][74]


A lot of people back then (a little more than a year ago, now feels like a decade ago to me), were starting to say that it would be impossible to work the issues out and reach a good launch cadence with that feature on the rocket. Even industry officials like George Sowers (then working on ULA) were saying that it really was not worth the trouble.

Ultimately, it took a year and a half, including a freak pad accident to surmount this challenge. Judging from the last two campaigns though, I think it was worth it in the end.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: baldusi on 05/17/2017 10:26 PM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?
Perhaps this will better explain to people how significant this performance was, considering it was also the heaviest F9 GTO payload to date !
The problem with orbital mechanics is that mixing apogee increase AND plane change is a lot cheaper than doing one and then the other one. I will yield to Lou to do such calculation, though.
I thought that the best usage of LV performance was to put the GTO payload on as high as possible apogee, and THEN once its on a super sync trajectory, it can use the lower speeds of the apogee to effect some inclination change and reduction in apogee on each orbital apogee and increase in perigee on each orbital perigee, done by the payload itself.

That led me to think that if SpaceX could create a mini ITS rocket that had perhaps 5+ days of mission endurance, it could do a bi elliptical transfer by itself, by going into a super sync orbit, doing the entire inclination change and apogee reduction in a single burn, then the perigee raising in the other half orbit and deliver a large number of GEO payloads into GEO-500m/s with zero inclination and just some circularization left, so the orbital period is a few hours away from GEO, so the payloads can pace themselves to go directly into their exact slots, although they would all be delivered to the same initial orbit.
The mini ITS would then do the required orbital transfer to re-enter and land, avoiding brute force trajectory corrections to get to the LZ.

Well, as long as you want to go to GTO, and you are not launching from the Equator, you will really have at least a two-burn profile mission. First you go to a parking orbit (say 185km circular), and then, when you are over the equatorial plane, you make your burn so that your apogee is also at the Equator.
But guess what? If you mix a an apogee burn, and a plane change burn, you actually make a vector sum of both solution vectors (assuming instantaneous impulse, which it isn't). But those vectors are orthogonal, so your resulting impulse vector will be at an angle to both. And thus you have something that is less than the sum of both. So doing both at the same time, actually saves delta-v.
Of course that once you are on the apogee transfer, the upper stage mass is dead weight. So you actually save total mass by letting the payload do the circularization at apogee (which will also involve a plane change). So, yes, the plane change is cheaper to do at apogee, but that's the payload's job. And since you are already doing an apogee increasing burn with your LV, you should also put some plane change in there and you will have less delta-v to GEO.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/18/2017 12:26 AM
The machine has evolved, and the most recent two flights have exhibited a new level of performance - to the extent that I'm convinced we are seeing at least a Block 4 second stage.

Not sure about two latest flights, but the last one was totally out of family. Looks like a different rocket.
The last two flights look like they are from the same family, despite first glance appearances. Minimum residual shutdown makes a big difference.  The last 1% of the fuel provides about 350 m/s of delta-V, for about a 220 m/s better deficit. 

I draw these on top of the existing plot, below.  First there is a parallel line through Echostar (thick blue line, for a new family).  This is for targetted shutdowns, and I agree represents a new family of increased performance compared to previous launches.    From this line you can move left by about 220 m/s (magenta arrow) and end up  with another family line, for minimum residual shutdowns.   This new line then extends up to the estimated 7.38 tonnes at GEO-1800. 
(http://www.lscheffer.com/images/F9graph.png)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Robotbeat on 05/18/2017 12:28 AM
Perhaps now I actually understand why people are so reluctant to even entertain the possibility that F9 expendable with zero margins might be able to put an 8.3 ton payload in GTO-1800 m/s. That would challenge every rocket in service, except for Ariane V and D4H.
It really must be hard to conceive that such a cheap rocket can get that much performance. But I'm a believer, eventually there will be one Block V expendable launch that will place something like a 7.5 ton payload to an orbit similar to this, and awe the world ! A payload large enough that in requires the same effort to put that 8.3 tons to GTO-1800 !
Actually, can anyone calculate what Ariane 5's payload would be if it were launched from 28 degrees?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/18/2017 02:26 AM
Perhaps now I actually understand why people are so reluctant to even entertain the possibility that F9 expendable with zero margins might be able to put an 8.3 ton payload in GTO-1800 m/s. That would challenge every rocket in service, except for Ariane V and D4H.
It really must be hard to conceive that such a cheap rocket can get that much performance. But I'm a believer, eventually there will be one Block V expendable launch that will place something like a 7.5 ton payload to an orbit similar to this, and awe the world ! A payload large enough that in requires the same effort to put that 8.3 tons to GTO-1800 !
Actually, can anyone calculate what Ariane 5's payload would be if it were launched from 28 degrees?

Wouldn't it be the same (10,500kg) but to GTO-1800 instead of GTO-1500?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: wannamoonbase on 05/18/2017 02:32 AM
Ultimately, it took a year and a half, including a freak pad accident to surmount this challenge. Judging from the last two campaigns though, I think it was worth it in the end.

Yeah it does, the last two rockets look like they were supercharged.

Still need a lot more launches before getting cocky.  But this it appears to be a big edge, looking forward to the Block 4 and 5.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: woods170 on 05/18/2017 08:28 AM
The machine has evolved, and the most recent two flights have exhibited a new level of performance - to the extent that I'm convinced we are seeing at least a Block 4 second stage.

Not sure about two latest flights, but the last one was totally out of family. Looks like a different rocket.
It is. No recovery hardware on stage 1 and different mission profile for stage 1.

Supercharged? No. Not yet.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: hans_ober on 05/18/2017 09:33 AM
Why don't they always do minimal residual shutdowns?

They can launch a 5t sat to GTO-1770 with a normal shutdown, but why not let it burn a little longer and use all the fuel?

Let's say that they're being conservative (and have a fuel margin in case of underperformance) and quote that they can launch the 5t sat to GTO-1800.
During the launch, all goes well and this reserve propellant isn't actually needed, so why not use it and burn to a higher apogee, which takes the satellite closer.

Also, what is the actual difference in dv for plane change vs higher apogee? Any graph for reference?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: vanoord on 05/18/2017 09:54 AM
Why don't they always do minimal residual shutdowns?

They can launch a 5t sat to GTO-1770 with a normal shutdown, but why not let it burn a little longer and use all the fuel?

Let's say that they're being conservative (and have a fuel margin in case of underperformance) and quote that they can launch the 5t sat to GTO-1800.
During the launch, all goes well and this reserve propellant isn't actually needed, so why not use it and burn to a higher apogee, which takes the satellite closer.

Also, what is the actual difference in dv for plane change vs higher apogee? Any graph for reference?

There's an argument that saving a bit of fuel to de-orbit the stage mightn't be a bad idea.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rpapo on 05/18/2017 10:09 AM
There's an argument that saving a bit of fuel to de-orbit the stage mightn't be a bad idea.
And now that the upper stage seems to have a longer life, why not wait until apogee to do the deorbit burn?  From 60,000km, very little fuel would be needed to lower the 400km perigee down into the atmosphere.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/18/2017 10:13 AM
May I ask how high an apogee would this launch have produced if it did zero inclination reduction ?
Perhaps this will better explain to people how significant this performance was, considering it was also the heaviest F9 GTO payload to date !
The problem with orbital mechanics is that mixing apogee increase AND plane change is a lot cheaper than doing one and then the other one. I will yield to Lou to do such calculation, though.
I thought that the best usage of LV performance was to put the GTO payload on as high as possible apogee, and THEN once its on a super sync trajectory, it can use the lower speeds of the apogee to effect some inclination change and reduction in apogee on each orbital apogee and increase in perigee on each orbital perigee, done by the payload itself.

That led me to think that if SpaceX could create a mini ITS rocket that had perhaps 5+ days of mission endurance, it could do a bi elliptical transfer by itself, by going into a super sync orbit, doing the entire inclination change and apogee reduction in a single burn, then the perigee raising in the other half orbit and deliver a large number of GEO payloads into GEO-500m/s with zero inclination and just some circularization left, so the orbital period is a few hours away from GEO, so the payloads can pace themselves to go directly into their exact slots, although they would all be delivered to the same initial orbit.
The mini ITS would then do the required orbital transfer to re-enter and land, avoiding brute force trajectory corrections to get to the LZ.

If you didn't have the extra mass of S2 it is not overall the most efficient to go to a super synchronous(SS). SS works because S2 expends more so the lighter satellite has less work to do. If there were no stages or no engines on the satellite the most efficient is:
1. Launch to parking
2. boost apogee at the equator to GEO.
3. boost perigee and remove inclination at apogee.
 
I have been playing with the equations.
   https://en.wikipedia.org/wiki/Geostationary_transfer_orbit
   https://en.wikipedia.org/wiki/Hohmann_transfer_orbit
I have made a bc(unix) program for doing the calcs. I have yet to incorporate the excellent calc from Lou.
   https://forum.nasaspaceflight.com/index.php?topic=36954.0

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/18/2017 10:16 AM
There's an argument that saving a bit of fuel to de-orbit the stage mightn't be a bad idea.
And now that the upper stage seems to have a longer life, why not wait until apogee to do the deorbit burn?  From 60,000km, very little fuel would be needed to lower the 400km perigee down into the atmosphere.

So what delta V can the GN2 thrusters do?
Maybe it is enough?

EDIT:

I get 20 m/s for the perigee lowering from 380km to 100km.
orbvel of 380x60000 = 1053 m/s
orbvel of 100x60000=1033 m/s
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/18/2017 10:54 AM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

I am not so sure on that. I certainly wouldn't recommend you go to Ukraine and say that.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rpapo on 05/18/2017 11:07 AM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/18/2017 11:07 AM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

I am not so sure on that. I certainly wouldn't recommend you go to Ukraine and say that.

Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/18/2017 11:11 AM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

I am not so sure on that. I certainly wouldn't recommend you go to Ukraine and say that.

Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.

I thought they were doing their upmost to keep Zenit going.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/18/2017 11:14 AM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.

So to continue with my calcs
if the isp is 200s for GN2?
we get a mass fraction of 1.01 or 1/100 of the 4500kg which is 45 kg.
if the isp is 300 it is 1.007 or .006*4500=27kg

EDIT:
Unknowns are
isp of GN2 thrusters?
kg of GN2 on board S2?

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/18/2017 11:18 AM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

I am not so sure on that. I certainly wouldn't recommend you go to Ukraine and say that.

Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.

I thought they were doing their upmost to keep Zenit going.

How? Ukraine will not use a Russian engine. It's a political suicide to anyone to even propose that.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Celestar on 05/18/2017 11:30 AM
The theoretical limit of cold gas (N2) thrusters seems to be around 80s [1]

[1] http://cdn.intechopen.com/pdfs-wm/37528.pdf

Celestar
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Kaputnik on 05/18/2017 11:31 AM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.

So to continue with my calcs
if the isp is 200s for GN2?
we get a mass fraction of 1.01 or 1/100 of the 4500kg which is 45 kg.
if the isp is 300 it is 1.007 or .006*4500=27kg

EDIT:
Unknowns are
isp of GN2 thrusters?
kg of GN2 on board S2?



Way off. isp of GN2 is more like 70s.

https://en.m.wikipedia.org/wiki/Cold_gas_thruster
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/18/2017 12:17 PM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.

So to continue with my calcs
if the isp is 200s for GN2?
we get a mass fraction of 1.01 or 1/100 of the 4500kg which is 45 kg.
if the isp is 300 it is 1.007 or .006*4500=27kg

EDIT:
Unknowns are
isp of GN2 thrusters?
kg of GN2 on board S2?



Way off. isp of GN2 is more like 70s.

https://en.m.wikipedia.org/wiki/Cold_gas_thruster

so isp of 70s
1.029
.029*4500=130kg
Sounds like a lot.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: LouScheffer on 05/18/2017 12:46 PM
Why don't they always do minimal residual shutdowns?
There are some practical considerations:
(a) The satellite has to be able to work when above GEO.  Not all satellites are designed to do this.
(b) With a targeted shutdown, maneuvers can be planned and verified in advance, and you know what ground stations are needed and where they should point.  (e.g, on Tuesday, at 4PM, we'll raise the perigee, using station X for commanding)  With minimum residual, maneuvers must be computed in real time - you need to see what the rocket does.  Plus they are more complex, at least two burns.
(c) Trajectory calculations are more complex for super-synchronous.   The moon's influence may need to be included.  One early super-sync mission (SuperBird 6 (http://space.skyrocket.de/doc_sdat/superbird-6.htm)) failed since the moon perturbed the orbit enough to give a too-low perigee for the transfer orbit.

Quote
Also, what is the actual difference in dv for plane change vs higher apogee? Any graph for reference?
Plot from  this post. (http://forum.nasaspaceflight.com/index.php?topic=41560.msg1674032#msg1674032)

(http://www.lscheffer.com/images/ssto.png)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: wannamoonbase on 05/18/2017 01:24 PM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.

20 m/s would be how long a burn for a MVac at minimum throttle, 0.5 seconds?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rpapo on 05/18/2017 01:40 PM
So what delta V can the GN2 thrusters do?
Maybe it is enough?
You were thinking along the same lines, but I somehow find it hard to imagine the GN2 system having enough propellant and energy to accelerate the second stage (4500kg?) by 20 m/s.

20 m/s would be how long a burn for a MVac at minimum throttle, 0.5 seconds?
Quite likely.  The real problem with that would simply be one of how to pull off such a short, precise burn, especially when you count in the preliminary steps, like ullage thrusting and so on.  The Merlin Vacuum is almost too powerful a tool for the job, while the nitrogen thrusters don't seem to be enough.

There would also be targeting accuracy to take into account here.  A small difference in a retro-burn at 60,000 km could make a large difference in where reentry will take place.  The deep south Pacific or Indian Ocean are big places, but even so...
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Basto on 05/18/2017 02:19 PM

There would also be targeting accuracy to take into account here.  A small difference in a retro-burn at 60,000 km could make a large difference in where reentry will take place.  The deep south Pacific or Indian Ocean are big places, but even so...

The stage will come down on its own eventually. At least with a deorbit burn you can give a push in the general direction you want it to go.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Kaputnik on 05/18/2017 02:36 PM
Is venting of residuals a possibility for deorbit impulse?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ulm_atms on 05/18/2017 03:02 PM
Is venting of residuals a possibility for deorbit impulse?

I was thinking the same thing.  Use all the GN2, and you still have what's left of the helium...the rest of the O2 to boil off (can you use the left over electrical power to heat the LO2 and change it into GO2 faster?)...and then basically increase the pressure in the O2 tank to it's max.  After that just open the O2 valve and let the pressurized gas be burped out the MVac and rinse repeat until all He/LO2 is gone?  That should provide some dV for deorbit.  As stated above...you don't need that much.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/18/2017 03:07 PM
...

Zenit-3SL can do 6.16 to a 1,477m/s deficit GTO. That's a ~95m/s difference. If they used less delta-v GTO, and they didn't had structural limits on the rocket, it would be much higher performance. Using a linear approximation I get 7.8 tonnes.

Isn't Zenit retired or on last launch?

I am not so sure on that. I certainly wouldn't recommend you go to Ukraine and say that.

Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.

I thought they were doing their upmost to keep Zenit going.

How? Ukraine will not use a Russian engine. It's a political suicide to anyone to even propose that.

Do they not have the capacity to develop an alternative?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Pete on 05/18/2017 04:15 PM
Is venting of residuals a possibility for deorbit impulse?

...and then basically increase the pressure in the O2 tank to it's max. ...

This is a scenario that should rather be avoided. The possibility, even the remote chance, of a rupturing O2 tank at a high apogee altitude is nightmare material.

A more sedate approach might well work just fine, as even a few m/s at a 60000km apogee (or even 35000km) will shift the perigee drastically.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: John Alan on 05/18/2017 08:19 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

I believe these are identified backwards: the payload is in the 384 x 70,181 km orbit; and the Falcon-9 upper stage rocket body is in the 381 x 69,839 km orbit.   Expect 18 SPCS to swap these in the next couple of days.
Swap has taken place:
42698   INMARSAT 5-F4  2017-025A      1409.24 min    24.52deg    70134km    385km
42699   FALCON 9 R/B    2017-025B      1401.51 min   24.47deg    69835km    378km

Well... there were no more burns...  :(

That stage will be up there for years... SAD!!   :-\

(on re-edit... my opinion is used stages should self deorbit within 1 year or much less... just my opinion)...  ;)

On later edit... @AncientU's post below
LouScheffer indicated within 25 years is the agreed on practice... Source from a couple pages back...
https://forum.nasaspaceflight.com/index.php?topic=41560.msg1679379#msg1679379 (https://forum.nasaspaceflight.com/index.php?topic=41560.msg1679379#msg1679379)
My opinion... with the increased flight rate world wide... this number needs revisited...
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/18/2017 08:39 PM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

I believe these are identified backwards: the payload is in the 384 x 70,181 km orbit; and the Falcon-9 upper stage rocket body is in the 381 x 69,839 km orbit.   Expect 18 SPCS to swap these in the next couple of days.
Swap has taken place:
42698   INMARSAT 5-F4  2017-025A      1409.24 min    24.52deg    70134km    385km
42699   FALCON 9 R/B    2017-025B      1401.51 min   24.47deg    69835km    378km

Well... there were no more burns...  :(

That stage will be up there for years... SAD!!   :-\

(on edit... my opinion is should require deorbit in 1 year or much less... just my opinion)...  ;)

Quite unusual/surprising for one of their second stages to not deorbit almost immediately.  Is that a failure or planned with the burn to limits?

Isn't the residual atmospheric drag sufficient below 400km to strip significant orbital energy each pass through perigee?  The VLEO constellation tech document had 2.9 years to reentry at 400km and 2.1 at 350km -- of course those were circular orbits with continual drag.  <25 years is the requirement, right?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/18/2017 08:56 PM
Quite unusual/surprising for one of their second stages to not deorbit almost immediately.  Is that a failure or planned with the burn to limits?

Isn't the residual atmospheric drag sufficient below 400km to strip significant orbital energy each pass through perigee?  The VLEO constellation tech document had 2.9 years to reentry at 400km and 2.1 at 350km -- of course those were circular orbits with continual drag.  <25 years is the requirement, right?
Completely different scenario, an object on a circular orbit with below 400Km apogee will be constantly subjected to the little atmosphere there.
The perigee is the point of faster speed, which means it will be below even 500Km for a tiny fraction of the whole orbit, time wise.

One question though, the higher energy orbit, wouldn't that furthermore mean that the cumulative period the GTO object must be exposed to the lower atmosphere is even longer, or the inverse ?

On the other hand, the influence of air drag has a lot to do with the objects surface vs its mass. A denser object will be subject to a smaller deceleration force than a less dense one. I think the F9 stage gets more deceleration due to this effect.

Anyhow, the shorter exposure to whatever little atmosphere there is during perigee should dominate the effects.

Ideally SpaceX should move to 200ish km perigee. That would accelerate re-entry to take place under a year.

Edit: This discussion really doesn't belong here. Move or delete my post freely mods.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: andrewsdanj on 05/18/2017 09:03 PM
Regarding the decay of Stage 2: The perigee height won't stay there for long. It will be perturbed higher or lower by the Moon etc. when nearer to apogee. This should be even more marker on a super-synchronous transfer orbit. Next question being, which way will it be perturbed and by how much...?

I notice Echostar 23's upper stage has a perigee of 179 km, it'll be interesting to see how quickly it drops from GTO from there!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: saliva_sweet on 05/18/2017 09:16 PM
Quite unusual/surprising for one of their second stages to not deorbit almost immediately.  Is that a failure or planned with the burn to limits?

To my knowledge, none of the second stages on SpaceX GTO flights have been actively deorbited. They stay up for a few months up to a couple of years.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: rsdavis9 on 05/18/2017 09:24 PM
Quite unusual/surprising for one of their second stages to not deorbit almost immediately.  Is that a failure or planned with the burn to limits?

To my knowledge, none of the second stages on SpaceX GTO flights have been actively deorbited. They stay up for a few months up to a couple of years.

I you peruse the launch elements you will see some falcon rocket body's still up there from years ago. And you will see a number of more recent ones missing.
So I think mostly they deorbit.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lar on 05/18/2017 09:43 PM
Is there a general thread for this ( do/don't S2s deorbit, how to deorbit them more cleverly, etc) that might be more well suited?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: ulm_atms on 05/18/2017 10:40 PM
Is venting of residuals a possibility for deorbit impulse?

...and then basically increase the pressure in the O2 tank to it's max. ...

This is a scenario that should rather be avoided. The possibility, even the remote chance, of a rupturing O2 tank at a high apogee altitude is nightmare material.

A more sedate approach might well work just fine, as even a few m/s at a 60000km apogee (or even 35000km) will shift the perigee drastically.

I miss wrote.  At max pressure, I mean max flight pressure....not max, if even 1 more pa it pops.  Or in other terms...max safe pressure.

And I agree with Lar, this has zip to do with Immarsat but can also not find a better home.  I will stop discussion unless a better home is found....

Carry on!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/19/2017 02:56 AM
Is there a general thread for this ( do/don't S2s deorbit, how to deorbit them more cleverly, etc) that might be more well suited?

F9 general thread?

GTO upper stages decay and are not deorbited. They don't have the lifetime to burn at apogee, or the performance to burn sooner.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lars-J on 05/19/2017 03:56 AM
Is there a general thread for this ( do/don't S2s deorbit, how to deorbit them more cleverly, etc) that might be more well suited?

F9 general thread?

GTO upper stages decay and are not deorbited. They don't have the lifetime to burn at apogee, or the performance to burn sooner.

They do have that lifetime now, or will soon.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gospacex on 05/19/2017 02:16 PM
Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.

I thought they were doing their upmost to keep Zenit going.

How? Ukraine will not use a Russian engine. It's a political suicide to anyone to even propose that.

Do they not have the capacity to develop an alternative?

This deserves an extended reply. Bear with me.

Yuzhnoye is a government enterprise.

In Ukraine, government enterprises are commonly used by political forces in government to milk money from state budget. A simplest way to do that is to buy materials through shell companies, paying them above market prices, and sell produced goods through other shell companies with reduced price (but there are many more creative methods).

As a result, Ukraine currently has some 3000 government enterprises (I believe USA has about 300?) and some 2000 of them are already bankrupt and are essentially dead, exist only on paper. The remaining ones are generally limping along, generating losses and subsisting on government loans and subsidies.

It's risky to have any sort of business relations with such an enterprise for any long-term project.

However. This general situation is not new or unknown, and generally everybody agrees than this can not continue forever and they all need to be privatized. People in power just stonewall this process (while always talking that it needs to be done) so that they can drain a few more hundreds of millions $$$ here and there.

Foreign observers (embassies, intelligence agencies, foreign business) must be understanding the situation as well. Thinking otherwise would assume they are naive idiots.

If anyone would be interested in partnering or otherwise using Ukrainian aerospace capabilities, I would say the only sensible choice would be to work through your official government channels and propose to privatize (buy) Yuzhnoye. Be ready that they will talk about this being a great idea but the actual paperwork process will be slow as a snail (the "stonewalling" thing); and you can get "interesting" proposals that, say, "it's better to form a joint company". As soon as these shenanigans begin, consider going public about it. Unlike situation in Russia, they are afraid of publicity.

This will be good for Ukraine as well - the way Yuzhnoye works today is not beneficial to the country in general, it is beneficial only to individuals who currently control it and enrich themselves through those schemes.

I believe Yuzhnoye can build reasonably good tanks / stages, and they can be very inexpensive (very low salaries compared to the West).

They also can produce some engines, but the ones definitely in production are small-to-medium thrust hypergolic engines. Largest seems to be RD-861 - a seven-ton thrust engine.

They _talk_ about having large(r) kerosene engines of 120-200 tons thrust "in development", but I would very carefully verify what do they actually have, not taking any words / presentations for granted. I would actually send my own engineers to see the goods. In the worst case, it may be just empty talk.

Also Yuzhnoye has some solid-rocket facilities (both fuel and motors), used mostly for military products.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/19/2017 02:18 PM
I ment to comment on this sooner, One can look up the NORAD ID for each spaceX GTO/Super Sync launch. What you will notice is each payload and upper stage has a separate (should be sequential) NORAD tracking ID. With that ID you can look up the decay dates for stages not currently in orbit. Stages that they immediately de-orbit do not get NORAD ID's.

space-track.org would be the site you go to dig up all those fun numbers. (That or state something that is statistically incorrect and several NSF members will dig out all the numbers to correct you ;) ).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Star One on 05/19/2017 02:25 PM
Why not? It's not like people in Yuzhmash are oblivious to the fact that RD-170 is not made in Ukraine.

I thought they were doing their upmost to keep Zenit going.

How? Ukraine will not use a Russian engine. It's a political suicide to anyone to even propose that.

Do they not have the capacity to develop an alternative?

This deserves an extended reply. Bear with me.

Yuzhnoye is a government enterprise.

In Ukraine, government enterprises are commonly used by political forces in government to milk money from state budget. A simplest way to do that is to buy materials through shell companies, paying them above market prices, and sell produced goods through other shell companies with reduced price (but there are many more creative methods).

As a result, Ukraine currently has some 3000 government enterprises (I believe USA has about 300?) and some 2000 of them are already bankrupt and are essentially dead, exist only on paper. The remaining ones are generally limping along, generating losses and subsisting on government loans and subsidies.

It's risky to have any sort of business relations with such an enterprise for any long-term project.

However. This general situation is not new or unknown, and generally everybody agrees than this can not continue forever and they all need to be privatized. People in power just stonewall this process (while always talking that it needs to be done) so that they can drain a few more hundreds of millions $$$ here and there.

Foreign observers (embassies, intelligence agencies, foreign business) must be understanding the situation as well. Thinking otherwise would assume they are naive idiots.

If anyone would be interested in partnering or otherwise using Ukrainian aerospace capabilities, I would say the only sensible choice would be to work through your official government channels and propose to privatize (buy) Yuzhnoye. Be ready that they will talk about this being a great idea but the actual paperwork process will be slow as a snail (the "stonewalling" thing); and you can get "interesting" proposals that, say, "it's better to form a joint company". As soon as these shenanigans begin, consider going public about it. Unlike situation in Russia, they are afraid of publicity.

This will be good for Ukraine as well - the way Yuzhnoye works today is not beneficial to the country in general, it is beneficial only to individuals who currently control it and enrich themselves through those schemes.

I believe Yuzhnoye can build reasonably good tanks / stages, and they can be very inexpensive (very low salaries compared to the West).

They also can produce some engines, but the ones definitely in production are small-to-medium thrust hypergolic engines. Largest seems to be RD-861 - a seven-ton thrust engine.

They _talk_ about having large(r) kerosene engines of 120-200 tons thrust "in development", but I would very carefully verify what do they actually have, not taking any words / presentations for granted. I would actually send my own engineers to see the goods. In the worst case, it may be just empty talk.

Also Yuzhnoye has some solid-rocket facilities (both fuel and motors), used mostly for military products.

Thank you for that comprehensive response as it was very informative.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/19/2017 02:51 PM
To help the US GTO de-orbit debate, NORAD ID's for all SpaceX GTO/Super Synch payloads and upper stages. To date all SpaceX upper stages to those orbits have stuck around long enough to be cataloged.

SES-8 39460, US 39461
Thiacom 6 39500, US 39501
AsiaSat 8 40107, US 40108
AsiaSat 6 40141, US 40142
ABS-3A 40424, Samex 7 40425, US 40426
MonacoSAT 40617, US 40618
SES-9 41380, US 41381
JCSAT-14 41471, US 41472
Thiacom 8 41552, US 41553
ABS 2 41588, EUTELSAT 117W B 41589, US 41590
JCSAT-16 41729, US 41730
Echostar 23 42070, US 42071
SES-10    42432, US 42433
Inmarsat-5 F4 42698, US 42699

It is left as an exercise for the reader to figure out which ones have decayed and any typos.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: friendly3 on 05/19/2017 03:05 PM
SES-8 39460, US 39461
Thiacom 6 39500, US 39501
AsiaSat 8 40107, US 40108
AsiaSat 6 40141, US 40142
ABS-3A 40424, Samex 7 40425, US 40426
MonacoSAT 40617, US 40618
SES-9 41380, US 41381
JCSAT-14 41471, US 41472
Thiacom 8 41552, US 41553
ABS 2 41588, EUTELSAT 117W B 41589, US 41590
JCSAT-16 41729, US 41730
Echostar 23 42070, US 42071
SES-10    42432, US 42433
Inmarsat-5 F4 42698, US 42699

It is left as an exercise for the reader to figure out which ones have decayed and any typos.

Thaicom and not Thiacom, also Satmex and not Samex.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: nicfit on 05/19/2017 03:51 PM
Regarding the decay of Stage 2: The perigee height won't stay there for long. It will be perturbed higher or lower by the Moon etc. when nearer to apogee. This should be even more marker on a super-synchronous transfer orbit. Next question being, which way will it be perturbed and by how much...?


Stages 2 re-entered in less than half a year for the SES8 et Thaicom 6, both supersync injection orbits --> the moon effect
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: stcks on 05/19/2017 04:38 PM
It is left as an exercise for the reader to figure out which ones have decayed and any typos.

Here is what I have gathered:

Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/19/2017 04:42 PM
The rather dramatic effect on the Abs-2/Eut-117 orbit comes from the moon too, right?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Comga on 05/19/2017 08:42 PM
This thread is drifting from discussing the May 15 Inmarsat 5 F4 launch.  These are interesting enough topics but there are dedicated threads for them elsewhere.  (I would love to see a single plot of the second stage apogee heights vs calendar days, but except for THIS second stage, it would go in a general discussion thread.)
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Lar on 05/19/2017 10:45 PM
This thread is drifting from discussing the May 15 Inmarsat 5 F4 launch.  These are interesting enough topics but there are dedicated threads for them elsewhere.  (I would love to see a single plot of the second stage apogee heights vs calendar days, but except for THIS second stage, it would go in a general discussion thread.)

Yes please... let's find a home for some of this.... interesting but off topic.... (PM me and I'll try to move stuff to the thread identified) Thanks!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/23/2017 01:45 AM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

I believe these are identified backwards: the payload is in the 384 x 70,181 km orbit; and the Falcon-9 upper stage rocket body is in the 381 x 69,839 km orbit.   Expect 18 SPCS to swap these in the next couple of days.
Swap has taken place:
42698   INMARSAT 5-F4  2017-025A      1409.24 min    24.52deg    70134km    385km
42699   FALCON 9 R/B    2017-025B      1401.51 min   24.47deg    69835km    378km


Still no maneuvers detected...

Would those be explained by timing so that once they start their burns they get to the right GEO slot, and right now with each orbit the get closer to that proper timing faster than if they did some substantial burns prior ?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Semmel on 05/23/2017 09:02 AM
42698   INMARSAT 5-F4   2017-025A      1401.67min   24.50deg   69839km   381km      
42699   FALCON 9 R/B   2017-025B           1410.43min   24.47deg   70181km   384km

I believe these are identified backwards: the payload is in the 384 x 70,181 km orbit; and the Falcon-9 upper stage rocket body is in the 381 x 69,839 km orbit.   Expect 18 SPCS to swap these in the next couple of days.
Swap has taken place:
42698   INMARSAT 5-F4  2017-025A      1409.24 min    24.52deg    70134km    385km
42699   FALCON 9 R/B    2017-025B      1401.51 min   24.47deg    69835km    378km


Still no maneuvers detected...

Would those be explained by timing so that once they start their burns they get to the right GEO slot, and right now with each orbit the get closer to that proper timing faster than if they did some substantial burns prior ?

I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: jpo234 on 05/23/2017 10:25 AM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: edkyle99 on 05/23/2017 02:13 PM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?
Not in my opinion (GEO is a better location), but then again this transfer orbit was given a higher than typical perigee, perhaps to allow for more time before starting ascent. 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: karanfildavut on 05/23/2017 06:35 PM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?

Generally, I was under the impression this is a bad idea due to the repeated transits through the Van Allen belts. Those tend to be hard on satellite electronics. My wager is that the satellite checkout is continuing in some form and that they will start the orbital changes as soon as they are satisfied. I'm sure they can use it to decongest bandwidth in their high demand areas (europe was mentioned before).

Also, AFAIK it's actually not that energetically expensive to change orbital slots in GSO since you can do a racetrack maneuver or something similar. Just raise or lower your orbit by a few km, drift till you get to the correct slot and re-enter. Low total dV expenditure.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: macpacheco on 05/23/2017 07:56 PM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?

Generally, I was under the impression this is a bad idea due to the repeated transits through the Van Allen belts. Those tend to be hard on satellite electronics. My wager is that the satellite checkout is continuing in some form and that they will start the orbital changes as soon as they are satisfied. I'm sure they can use it to decongest bandwidth in their high demand areas (europe was mentioned before).

Also, AFAIK it's actually not that energetically expensive to change orbital slots in GSO since you can do a racetrack maneuver or something similar. Just raise or lower your orbit by a few km, drift till you get to the correct slot and re-enter. Low total dV expenditure.
Not energetically expensive, but how long it would take to go half way around the globe that way ? How many months ? Timing can be very important in several situations.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: envy887 on 05/23/2017 09:50 PM
Not energetically expensive, but how long it would take to go half way around the globe that way ? How many months ? Timing can be very important in several situations.
For 30 m/s it can drift at least 180 degrees in 35 days. That's with circular orbits but it might be cheaper and faster to use elliptical orbits to drift.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: psionedge on 05/24/2017 06:25 PM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?
They will probably have to go to Geo to check out the satellite before the manufacturer hands it over to the customer. You aren't going to be verifying link budgets and channel performance in GTO.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/25/2017 12:52 AM
I dont think so. With two burns, one that parks perigee somewhere between where it is now and GEO height and an other one for the final perigee raise they can get to almost any point within 2 or 3 orbits. By now, they must have at least 10 orbits.

The satellite is supposed to be a spare. Would it make sense to leave it in the current transfer orbit until it is actually needed?
They will probably have to go to Geo to check out the satellite before the manufacturer hands it over to the customer. You aren't going to be verifying link budgets and channel performance in GTO.

It will also last longer in GSO, GTO does multiple passes through the Van Allen each day.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: friendly3 on 05/26/2017 12:11 AM
Tweeted, but when I went to RT, it said action unavailable and that's because they deleted it.....sorry, which I could have grabbed the pics, but at least screenshot the deleted tweet.

Oh, they deleted it because they typoed. Proton 9 ;D

Anyway, they haven't tweeted the correction.....we get the message and the milestone.

(http://u.cubeupload.com/friendly3/20170514193341.jpg)

Well you can't blame them, even to this day NASA's website says Inmarsat 5 F4 was launched from the Cape on a Proton-M ::) :

https://nssdc.gsfc.nasa.gov/nmc/spacecraftOrbit.do?id=2017-025A

https://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2017-025A

EDIT: they fixed this in less than 24 hours, so the links now show a Falcon 9 Full Thrust as the launcher :D
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: kevin-rf on 05/26/2017 12:27 AM
That's one funny looking Proton.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Antares on 05/27/2017 01:41 AM
A 541 at much less than half the cost.  If I were ULA or OrbTK,
late career: buy survival bunker
mid career: cushy job with GovSpace
early career: leave the industry or demand better options from SpaceX.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/27/2017 04:32 PM
To be fair - and assuming this campaign did do a depletion burn as theorized - this was a 531/4M+5,4  performance (see the WGS campaigns for Delta IV and the AEHF campaigns for Atlas V).

It is assumed that Block 5 may match 541, while still being a two stage kerolox LV (and about 20t heavier than said Atlas V variant).
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: AncientU on 05/27/2017 07:00 PM
To be fair - and assuming this campaign did do a depletion burn as theorized - this was a 531/4M+5,4  performance (see the WGS campaigns for Delta IV and the AEHF campaigns for Atlas V).

It is assumed that Block 5 may match 541, while still being a two stage kerolox LV (and about 20t heavier than said Atlas V variant).

You are referring to high energy orbits, right?
To LEO, Block 5 will far surpass Atlas V 551; may come close to matching Delta IV Heavy.
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: Dante80 on 05/27/2017 07:22 PM

You are referring to high energy orbits, right?
To LEO, Block 5 will far surpass Atlas V 551; may come close to matching Delta IV Heavy.

Yep, we were talking about GTO missions. Falcon 9 is an absolute monster as far as LEO is concerned. You cannot beat kerolox in that profile.

Falcon 9 block5 can probably match the ISS throw-weight of Ariane 5 ES. And that is a 760t rocket!
Title: Re: SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION
Post by: gongora on 08/09/2017 03:30 AM
[SpaceNews] Inmarsat says business largely immune to current capacity oversupply (http://spacenews.com/inmarsat-says-business-largely-immune-to-current-capacity-oversupply/)
Quote
Inmarsat expects to have three new satellites [I6-F1,I6-F2,GX-5] in orbit by 2021. None have yet been assigned to launchers.
...
Inmarsat executives have said that Qatar Airways’ commitment to equip 130 aircraft with GX inflight connectivity hardware was a strong motive for the operator to invest in GX-5. Pearce said Inmarsat-5 F4 will support inflight connectivity demand over Europe until GX-5 arrives in 2019. After that, Inmarsat-5 F4 will probably shift to Asia, he said.