SpaceX Falcon 9 - Inmarsat 5 F4 - May 15, 2017 - DISCUSSION

[tvg98]

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.

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

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

The next two launches, #CRS11 and #BulgariaSat, will be the last two without this improved loading system.

https://twitter.com/jrourourou/status/864268612286242816

Maybe this was the maiden flight of the long-awaited Block IV?

[LouScheffer]

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.

[edkyle99]

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

[edkyle99]

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

[cppetrie]

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.

[stcks]

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

[x15_fan]

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.

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

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

The next two launches, #CRS11 and #BulgariaSat, will be the last two without this improved loading system.

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?

[edkyle99]

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

[shplatt]

Anyone else notice the crickets at the end of the webcast, just as John was signing off?

[Herb Schaltegger]

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.

[abaddon]

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?

[abaddon]

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.

[Navier–Stokes]

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.

[cppetrie]

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.

[abaddon]

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.

[wannamoonbase]

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.

[abaddon]

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

[wannamoonbase]

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.

[ChrisC]

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.

[edkyle99]

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