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

[Michael Baylor]

Yes, that's him for sure.

[TrueBlueWitt]

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?

[punder]

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.

[yokem55]

Anyone want to take a gander at what the apogee would be if you are at 36,000km/hr with a 300 km peri?

[zubenelgenubi]

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?

[rockets4life97]

On time and on cadence. Looking forward to the banality of this every two weeks.

[DecoLV]

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!
 

[Orbiter]

That first stage burn had a pretty impressive length to it. Looked like SECO happened at T+2:49 or so.

[ulm_atms]

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.

[rickl]

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.

[Michael Baylor]

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)

[lonestriker]

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.

[JimO]

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?

[zubenelgenubi]

What is the structure that the people with the light wands were entering (background, left) at the end of the webcast?

[Michael Baylor]

For those wondering... https://twitter.com/RocketJoy/status/864273693395918848

[AncientU]

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

[zubenelgenubi]

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

[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

[rickl]

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.

[FutureSpaceTourist]

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

Edit to add:

Confirmation poster got earlier and later mixed up!

I meant later; closer to liftoff. Apologies lol

https://twitter.com/jrourourou/status/864284474808389634