Author Topic: SpaceX Falcon Heavy : Arabsat 6A : LC-39A : April 11, 2019 - DISCUSSION (Read 308837 times)

fthomassy · « **Reply #280 on:** 04/08/2019 04:26 am »

Quote from: Coastal Ron on 04/08/2019 01:41 am

Quote from: matthewkantar on 04/08/2019 12:44 am
The yellow are some of the eight (larger but similar looking) hold down/ release lugs.
Those are the attachment points for the legs, and as far as I know they are only hinge points.

Both. Leg hinges above the hold down.

stcks · « **Reply #281 on:** 04/08/2019 12:19 pm »

Quote from: stcks on 04/08/2019 02:16 am

We first saw the gimbal sleeve (I made this term up just now) on SES-10 iirc and yes, that's how they work.

Here are two of those gimbal sleeve thingies (perhaps someone can chime in with what they are actually called) clearly visible on two engines that flew on SES-10. This screenshot taken from

Steven Pietrobon · « **Reply #282 on:** 04/08/2019 01:29 pm »

Let there be light! That's some serious engineering there.

Jimmy_C · « **Reply #283 on:** 04/08/2019 03:12 pm »

Quote from: vaporcobra on 04/07/2019 09:24 pm

Quote from: FutureSpaceTourist on 04/07/2019 04:51 pm
https://twitter.com/spacex/status/1114932679688900608

Quote
Falcon Heavy’s 27 Merlin engines generate more than 5 million pounds of thrust at liftoff, making it the world’s most powerful operational rocket by a factor of two

Full image is actually quite a bit larger

What are the silver things near the bottom of the engine bells?

Lars-J · « **Reply #284 on:** 04/08/2019 04:28 pm »

Quote from: Jimmy_C on 04/08/2019 03:12 pm

What are the silver things near the bottom of the engine bells?

Bumper guards, to prevent or reduce nozzle damage if one of the gimbal actuators fails and they bump each other.

pb2000 · « **Reply #285 on:** 04/08/2019 04:50 pm »

Quote from: Chris Bergin on 04/08/2019 01:30 pm

And this will work. He's NASA PAO. Confirms NET Wednesday.

https://twitter.com/DerrolNail/status/1115237306254929920

He deleted the tweet, but it's what were hearing, so it will be.

Any idea why there isn't any official word yet? I fly home on Saturday, so I'm starting to worry a bit

ZachS09 · « **Reply #286 on:** 04/08/2019 04:52 pm »

It's actually a good thing that it's launching on Wednesday, given that the weather is 80% favorable.

Now they don't have to worry about dealing with thunderstorms and low cloud coverage.

Comga · « **Reply #287 on:** 04/08/2019 05:13 pm »

Quote from: flyright on 04/06/2019 05:26 pm

Quote from: Comga on 04/06/2019 04:57 pm
Quote from: RocketLover0119 on 04/06/2019 04:12 pm
Mr. Steven has departed port also, the entire fleet is on deck for this FH mission!
...

So what can Mr Steven do without arms and a net?
Something with the big, round, raft?

They've gotten pretty good at fishing fairings out of the water.

Confirmed by Musk months ago:

Quote from: Elon Musk

Falcon fairing halves missed the net, but touched down softly in the water. Mr Steven is picking them up. Plan is to dry them out & launch again. Nothing wrong with a little swim.

Lar · « **Reply #288 on:** 04/08/2019 05:36 pm »

Quote from: Lars-J on 04/08/2019 04:28 pm

Quote from: Jimmy_C on 04/08/2019 03:12 pm
What are the silver things near the bottom of the engine bells?

Bumper guards, to prevent or reduce nozzle damage if one of the gimbal actuators fails and they bump each other.

Are those a remove before flight item? I assume yes?

ChrisGebhardt · « **Reply #289 on:** 04/08/2019 06:01 pm »

Quote from: ChrisGebhardt on 04/06/2019 02:54 pm

CROSS POSTING - NSF member meet up on Monday (Go Falcon Heavy!)

The official meetup time has been changed (as of 2019-04-05 7:50 pm EST).

Hello all,

NSF will once again be hosting a member & friends meetup to celebrate the next Falcon Heavy launch (NET 2019-04-09).

We had such success at last year’s meetup that we will again be gathering at Fishlips Bar & Grille in Port Canaveral on MONDAY, April 8th from 6:30 pm to 8:30 pm.

NSF MEETUP

Monday, April 8th from 6:30 pm to 8:30 pm EST

Fishlips Waterfront Bar & Grill
610 Glenn Cheek Dr.
Cape Canaveral, FL 32920
321-784-4533

If you plan on attending or are a strong "maybe", please take a minute to fill out this NSF MEETUP POLL..

NSF HOODIE GIVE-AWAY (to be held at the meetup)

In addition to a few door prizes, we will be giving away a BEAUTIFUL NSF hoodie (suitable for wearing). All you have to do is...

Guess the closest launch time (day, hours, seconds).
Tie breaker: Guess the landing time (day, hours, seconds) of the first booster to land.

Please pass the word... the more the merrier! Please let us know if you have any questions.

Thanks!
Chris M.

NOTE: If the FH launch slips again, we will move the meetup to the night before the launch.

(Original post: https://forum.nasaspaceflight.com/index.php?topic=47723.msg1932295#msg1932295)

Hey guys. This IS happening tonight (we will not delay). We will see you all at FishLips at 6:30p TONIGHT for a good NSF time celebrating space and Falcon Heavy. Please RSVP if you haven’t already.

ugordan · « **Reply #290 on:** 04/08/2019 06:04 pm »

Quote from: Lar on 04/08/2019 05:36 pm

Quote from: Lars-J on 04/08/2019 04:28 pm
Quote from: Jimmy_C on 04/08/2019 03:12 pm
What are the silver things near the bottom of the engine bells?

Bumper guards, to prevent or reduce nozzle damage if one of the gimbal actuators fails and they bump each other.
Are those a remove before flight item?

They are not.

pb2000 · « **Reply #291 on:** 04/08/2019 09:10 pm »

I'm hanging out at the port and I saw a GO boat headed out to sea and vesselfinder suggests it was Mr Steven. I thought he left days ago??

ChrisGebhardt · « **Reply #292 on:** 04/08/2019 09:32 pm »

Quote from: pb2000 on 04/08/2019 09:10 pm

I'm hanging out at the port and I saw a GO boat headed out to sea and vesselfinder suggests it was Mr Steven. I thought he left days ago??

Turned out to be sea trials.

rangerpax · « **Reply #293 on:** 04/08/2019 10:08 pm »

Mr Steven was out for a day or so for maneuvers, then she came back. Went out again today per SpaceX Fleet on Twitter. I missed it by about 45 minutes.

https://twitter.com/SpaceXFleet/status/1115355536931917825?s=19

envy887 · « **Reply #294 on:** 04/09/2019 01:08 pm »

Is there a delay day approved for turnaround in case tomorrow doesn't work?

ZachS09 · « **Reply #295 on:** 04/09/2019 02:58 pm »

Quote from: envy887 on 04/09/2019 01:08 pm

Is there a delay day approved for turnaround in case tomorrow doesn't work?

There is a backup attempt on April 11th; weather on that day is 90% favorable.

pb2000 · « **Reply #296 on:** 04/09/2019 02:59 pm »

Has it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?

LouScheffer · « **Reply #297 on:** 04/09/2019 03:14 pm »

Quote from: pb2000 on 04/09/2019 02:59 pm

Has it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?

As far as I know the trajectory has not been announced. There are several ways increased performance could be used to reduce the delta-V needed by the satellite to reach GEO:
(a) Super-synchronous apogee, to make the plane change less costly
(b) Reduce inclination at GTO injection burn
(c) increased perigee, as GPS did.

or even some combination of these. (a) depends on if the operator wants it, and the satellite can handle it. (b) is less efficient that (a), but easy for both the satellite (it's a traditional GTO) and the rocket (just two burns). (c) usually requires a third burn after satellite release to dispose of the second stage.

Given the additional complexities of (a) and (c), and since it's an early use of the FH, I'm guessing (b). But the others are certainly possible.

aero1310 · « **Reply #298 on:** 04/09/2019 05:09 pm »

Does anyone know for sure why the delay? Obviously weather being a factor but what about FH itself? Would SpaceX been ready to go if conditions were clear? Just find the minimal communication a little wierd...

I'm just thinking outside the box here and reasons that would cause extra time to be taken on new rocket engines... with the new thrust numbers Elon announced, were they prepared for that news or do they have to go back and make a ton of adjustments according to the more power the block V produces.

Also, how old are the computer systems? I wonder if they are still using old systems for a newer rocket, so adjustments and such still have to be done in which a matter that it takes time.

ugordan · « **Reply #299 on:** 04/09/2019 05:17 pm »

Quote from: aero1310 on 04/09/2019 05:09 pm

I'm just thinking outside the box here and reasons that would cause extra time to be taken on new rocket engines... with the new thrust numbers Elon announced, were they prepared for that news or do they have to go back and make a ton of adjustments according to the more power the block V produces.

Prepared for the news? They are not really "new" engines any more. This is basically the same engine variant that flew on the first Block 5 almost a year ago, potential NASA-mandated turbine changes notwithstanding.

Quote from: aero1310 on 04/09/2019 05:09 pm

Also, how old are the computer systems? I wonder if they are still using old systems for a newer rocket, so adjustments and such still have to be done in which a matter that it takes time.

You almost make it sound like they realized just the other day that this thing has more thrust than they expected or knew about.

There have certainly been changes with Block 5 under the hood which is why I consider this FH to not be the 2nd launch, but more like 1.5th launch from a standpoint of FH vehicle being "proven". Modern flight computers are really not lacking in computer power for the thrust upgrade to matter. The structural and aeroloads on the vehicle due to the thrust upgrade are bigger factors, which will play into trajectory modelling.