SpaceX Falcon Heavy : Arabsat 6A : LC-39A : April 11, 2019 - DISCUSSION

[cscott]

Elon thinking about worst case, as usual:

twitter.com/elonmusk/status/1115998728878321672

First flight for Falcon Heavy Block 5 means there is some risk of failure between 5% to 10% imo. Many good design improvements from Falcon Heavy demo, but the changes are unproven.

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

ArabSat deliberately jumped over the STP-2 "test" flight, so it's pretty clear the customer was making a knowing tradeoff between increased risk and time-to-launch.  Eyes wide open.

[ugordan]

Anyone know if they're still tracking for an attempted launch at the opening of the window? The FH going vertical was pushing the usual timeline they'd like to have after going vertical (9 hours?)

[birdman]

Anyone know if they're still tracking for an attempted launch at the opening of the window? The FH going vertical was pushing the usual timeline they'd like to have after going vertical (9 hours?)

As far as I know it's still 6:35, but I really do hope it slips later because then I won't be at work and can watch it, lol.

[matthewkantar]

Look back at what the launch sector incumbents were saying about Iridium putting all of their eggs in the Falcon9 basket before F9 was even flying. 9 years later, all 65 sats are up safely (and bringing home the bacon) for 7.5 million dollars a piece.

No risk, no reward. In my opinion, betting Arab Sat now is much less risky than Iridium’s gamble. Knocking on wood, it is important to note past results do not = future outcomes.

[Herb Schaltegger]

Just wanted to say I quite enjoyed Chris G.'s and Das Valdez's streams this morning from the remote camera sites and inside the perimeter fence. It was a treat to watch the stack go vertical live. Thanks to all involved.

[wannamoonbase]

Also, I think Elon knows the general public likes stuff blowing up. So increasing the chances of failing may increase the hype a bit. 

There is a paying customer with valuable payload on top.  He will  not be talking up rapid unscheduled disassembly today.

[RoboGoofers]

https://twitter.com/nextspaceflight/status/1115987063608881152

Close-up of the payload fairing for the #Arabsat6A mission. Note the additional heat shielding. #FalconHeavy #SpaceX

Why does the fairing nose need extra heat shielding?  Are they punching extra hard through MaxQ?

It's got to be a test for Starship. either the new SpaceX metal blend or transpiration cooling test.

[Glorky FCY]

https://twitter.com/nextspaceflight/status/1115987063608881152

Close-up of the payload fairing for the #Arabsat6A mission. Note the additional heat shielding. #FalconHeavy #SpaceX

Why does the fairing nose need extra heat shielding?  Are they punching extra hard through MaxQ?

It's got to be a test for Starship. either the new SpaceX metal blend or transpiration cooling test.

Only if they recover the fairing before it hits the water. 

[haywoodfloyd]

There is a black stripe or some kind of plumbing running down the sides of the rockets.
The one on the right hand booster appears to be thicker (wider) than the other 2.
Any idea why?

[Joffan]

Why does the fairing nose need extra heat shielding?  Are they punching extra hard through MaxQ?

It's got to be a test for Starship. either the new SpaceX metal blend or transpiration cooling test.

More likely you're seeing the benefit of recovering flown hardware; the design can be improved based on the actual observed effects of flight. But there is also, as you speculate, the potential for some small-scale testing that takes advantage of that recovery. I would describe that as possible rather than probable, though.

[OxCartMark]

It's got to be a test for Starship. either the new SpaceX metal blend or transpiration cooling test.

Or lightning protection or radar reflecty bit for tracking its fall or a better attachment point for lifting onto ship or something to do with making it tolerant of salt water or a chrome bumper for retro-coolness or...

[Lars-J]

There is a black stripe or some kind of plumbing running down the sides of the rockets.
The one on the right hand booster appears to be thicker (wider) than the other 2.
Any idea why?

The boosters are identical - One of them is just rotated 180 degrees. All F9's and FH cores have a strip of thicker "plumbing" (commonly called a racetrack) on one side, and a thinner one on the other side.

EDIT: Compare these images from there tweets, opposite sides:
https://twitter.com/nextspaceflight/status/1116013597266673670
https://twitter.com/izqomar/status/1116017242075017216

[RoboGoofers]

It's got to be a test for Starship. either the new SpaceX metal blend or transpiration cooling test.

Or lightning protection or radar reflective bit for tracking its fall or a better attachment point for lifting onto ship or something to do with making it tolerant of salt water or a chrome bumper for retro-coolness or...

lightning protection- that's what the lightning towers and lightning rules are for.
radar reflectivity- wouldn't need stainless sheet steel, just radar reflective paint.
coolness factor- they would paint it shiny, not bolt on stainless sheet.
lifting? - CF is strong enough
saltwater- if CF is no good in saltwater I doubt they'd switch to steel fairings. but if so why such a small test patch?

[intelati]

Current upper level winds, 5PM estimate, 8PM estimate

Holy Jeez.

Fingers crossed

[JimO]

The later in the window, the darker the sky. GTO insertion and fuel purge might be visible pre-dawn in Africa.
Heavy-1 put on quite a sky show for SpaceX employees in California [and a million others]:
FH [falcon heavy] escape burn to Mars Feb 06, 2018 observed from SW USA   
http://satobs.org/seesat_ref/misc/180206_fh_s2_burn3_d2.pdf

[AC in NC]

Is it correct that the "Upper Level Winds" rule is for shear rather than speed?  Yes, I snap-glanced at Wikipedia?

[ZachS09]

According to the 8 PM showing of the ULW, the numbers range from 36 to 38.

What are the top limits of the ULW that are unfavorable for the Falcon Heavy?

[AC in NC]

According to the 8 PM showing of the ULW, the numbers range from 36 to 38.

What are the top limits of the ULW that are unfavorable for the Falcon Heavy?

Wikipedia said 30knts at 50m but only Shear Conditions for ULW

edit: 30 not 35.

[ZachS09]

Where on Wikipedia did you get your info from?

[AC in NC]

Where on Wikipedia did you get your info from?

Obviously FH may vary.

https://en.wikipedia.org/wiki/Launch_commit_criteria#Falcon_9

Falcon 9
Falcon 9 COTS Demo F1 Launch.jpg
NASA has identified the Falcon 9 vehicle cannot be launched under the following conditions. Some can be overridden if additional requirements[which?] are met.[3]

sustained wind at the 162 feet (49 m) level of the launch pad in excess of 30 knots (56 km/h; 35 mph),
upper-level conditions containing wind shear[quantify] that could lead to control problems for the launch vehicle,
launch through a cloud layer greater than 4,500 feet (1,400 m) thick that extends into freezing temperatures,
launch within 19 kilometres (10 nmi) of cumulus clouds with tops that extend into freezing temperatures,
within 19 kilometres (10 nmi) of the edge of a thunderstorm that is producing lightning within 30 minutes after the last lightning is observed,
within 19 kilometres (10 nmi) of an attached thunderstorm anvil cloud,
within 9.3 kilometres (5 nmi) of disturbed weather clouds that extend into freezing temperatures and contain moderate or greater precipitation,
within 5.6 kilometres (3 nmi) of a thunderstorm debris cloud,
through cumulus clouds formed as the result of or directly attached to a smoke plume.
The following should delay launch:

delay launch for 15 minutes if field mill instrument readings within 9.3 kilometres (5 nmi) of the launch pad exceed +/- 1,500 volts per meter, or +/- 1,000 volts per meter,
delay launch for 30 minutes after lightning is observed within 10 nautical miles (19 km; 12 mi) of the launch pad or the flight path.