totm nov 2023 SpaceX Discussion Thread

[RCgothic]

I can see the tweet that's linked but it won't load any others on my mobile browser which is 99% of how I view the internet.

[magnemoe]

7 hours ago, RCgothic said:

The engine plumes won't directly impinge on the centre of the spray pattern.

The water does get to full height before engine ignition, but if it isn't a problem before ignition it won't be after a supersonic flow is acting like a repulsor.

Yes, for perspective the old IR guided manpads has been pretty ineffective against large passenger or cargo planes simply because they aimed at the rear of the engines but could not enter because the airflow.  That is an 5-10 kg missile going supersonic and not able to enter an large turbofan. 
If you manage to get water going at 100 km/h enter an 200 bar rocket engine after passing the supersonic flame front I say its interesting, might be useful for fusion research  

[RCgothic]

A few days ago now SpaceX filed the IFT mishap report. There's no particular detail reported about what's in it or what corrective actions need to be taken before the next flight.

https://www.google.com/amp/s/arstechnica.com/space/2023/08/let-the-review-begin-spacex-takes-another-step-toward-launching-starship-again/amp/

To recap here are the areas I think need improving:

1) The pad didn't withstand launch. This is the area that's had the most obvious improvements in foundations and deluge system.

2) FTS didn't work as planned. The next flight will have longer det cord and more FTS units.

3) Hydraulic failure of TVC. B7 was the last booster to use hydraulic TVC, is electric from here on out.

4) Engine/plumbing reliability. They're always working on it. Possibly some ways still to go with recent static fire aborts, but it's not clear B9 is the latest state of the art or had the most recent raptor versions, so it's hard to read too much into. Even if they're not the nearest however, the B9/realtor combos will need to be good enough for flight.

5) Engine shielding/isolation. Apparently the engine protections were patched onto B7, and B9 and later are better. If there is a problem in flight like with B7 it should be better contained.

Edited August 17, 2023 by RCgothic

[Exoscientist]

On 8/12/2023 at 5:41 PM, darthgently said:

Around the 1h45m+ mark they start poking around the launch mount and deluge area.  Paint held up so water is converting a lot of heat to steam.  Some surface cracking in the high temp Fondag concrete layer

 

I'm  leaning to the methane Tanker SS guess in the comments

 Saw this on Reddit:

 

 SpaceX tearing up some sections of the concrete after the latest static fire test. Also have they revealed what’s under the tarp covering the steel plate after the deluge:

 

  Robert Clark

Edited August 17, 2023 by Exoscientist

[darthgently]

3 hours ago, Exoscientist said:

 Saw this on Reddit:

 

 SpaceX tearing up some sections of the concrete after the latest static fire test. Also have they revealed what’s under the tarp covering the steel plate after the deluge:

 

  Robert Clark

My understanding is those cracks are just in the Fondag as discussed.  Did I miss something?

They could be pulling Fondag to inspect the concrete below, doesn't necessarily mean the lower layer cracked.  I watched those vids when they came out and didn't end up with the same impression you did.

We are in an info starved condition so conclusions are pointless

 

[RCgothic]

It's been reported on Reddit that Booster 9 has been photographed with its hot stage ring installed. Credit to RGV Aerial Photography.

[Exoscientist]

On 8/10/2023 at 1:27 PM, tater said:

 

 The steel deluge plate is covered by a blue tarp there.

 

   Bob  Clark

[RCgothic]

The tarp is just to keep dust and similar out of the deluge system whilst they're working, it's not especially significant.

[Exoscientist]

7 hours ago, RCgothic said:

The tarp is just to keep dust and similar out of the deluge system whilst they're working, it's not especially significant.

 

 Could be. Any one know of images of the water deluge steel plate after the test without the static burn? Was it covered by a tarp as well then?

  Bob Clark

[tater]

 

Go out of town for the better part of a week, then spend all %$#@%# day moving my daughter back into the dorms, and IFT-2 looks like it might be happening. Woot!

The end of the month date mentioned online jibes with what I have heard via text from Houston, FWIW. At least that's what they have penciled in.

 

 

[Pthigrivi]

3 hours ago, tater said:

 

I like the dude at the top just chillin playing roblox. 

[tater]

~12 hours

 

[tater]

Booster on the move

 

[StrandedonEarth]

1 hour ago, tater said:

Booster on the move

 

*caveman grunting intensifies *

[tater]

 

 

[tater]

 

[RCgothic]

Booster 9 had a spin prime last night at 8:11pm.

 

 

[Exoscientist]

Does SpaceX want to hide that some engines had to be changed after the last static test?

 

 

  Robert Clark

  

[Meecrob]

2 hours ago, Exoscientist said:

Does SpaceX want to hide that some engines had to be changed after the last static test? 

I guess you are trying to get at the fact that "the internet" thinks Raptor engines are a scam, but covers are frequently used in aerospace. Especially on engines. Why are they using them now and not before? Good question, but keep in mind this is a flight test campaign where they are constantly refining their procedures. It is common to see something added (such as engine covers) when something else is modified (like the OLT).

[tater]

 

I will certainly be asleep.

[CBase]

5 hours ago, Exoscientist said:

Does SpaceX want to hide that some engines had to be changed after the last static test?

For SpaceX the measurement of success is not a positive press release with some senator handshaking for next contract, but flying rockets. The open design and operation of starbase are a strong statement they couldn't care less about hiding stuff. Actually I don't think Elon even cares about your, mine or any public opinion about starship at all.

There was recently an article on ars technica about valve failures due to humidity. Simple covers spacegrade engine protection sound like a very Kerbal SpaceX solution, doesn't it ?

[Nuke]

3 hours ago, Meecrob said:

I guess you are trying to get at the fact that "the internet" thinks Raptor engines are a scam, but covers are frequently used in aerospace. Especially on engines. Why are they using them now and not before? Good question, but keep in mind this is a flight test campaign where they are constantly refining their procedures. It is common to see something added (such as engine covers) when something else is modified (like the OLT).

seems like you would want to take engines that failed or performed poorly back to the shop for a post mortem. in order to help improve the design. 

[Royalswissarmyknife]

1 hour ago, CBase said:

Simple covers spacegrade engine protection sound like a very Kerbal SpaceX solution, doesn't it ?

Furniture moving covers

[darthgently]

53 minutes ago, Royalswissarmyknife said:

Furniture moving covers

Truckers would call them cargo blankets, but most people see them wrapped around their furniture by household movers, so "furniture..."

[tater]

 

Conf of scrub per MCC

But possible static fire!