totm nov 2023 SpaceX Discussion Thread

[RealKerbal3x]

13 minutes ago, Spaceception said:

Does anyone think they could have Starship stacked on Superheavy? That would be a sight to see. But they would need a new crane for it, right? I don't think the current ones can reach high enough.

The crane that they're currently using to build the high bay is pretty big, they might be able to use that.

[tater]

 

[RCgothic]

2 hours ago, RealKerbal3x said:

The crane that they're currently using to build the high bay is pretty big, they might be able to use that.

In order to fuel an upper stage they will need a service tower. If you're building a tower anyway, might as well stick a hammerhead crane on too of it...

[mikegarrison]

1 hour ago, RCgothic said:

In order to fuel an upper stage they will need a service tower. If you're building a tower anyway, might as well stick a hammerhead crane on too of it...

Cranes don't usually need to survive the environment of being directly next to a launching heavy-lift rocket.

[hms_warrior]

yeah but usually you don't launch rockets that size at this rate. Having a way to move booster and Starship seperatly to the launchpad and then stack them right there might be easier than stacking them somewhere else and then moving the whole stack. 

Edited August 28, 2020 by hms_warrior

[tater]

 

 

[mikegarrison]

34 minutes ago, hms_warrior said:

yeah but usually you don't launch rockets that size at this rate. Having a way to move booster and Starship seperatly to the launchpad and then stack them right there might be easier than stacking them somewhere else and then moving the whole stack. 

Considering they haven't launched one yet, I think "at this rate" is counting your chickens a little too far before they have hatched.

Obviously, if SpaceX is going to meet its vision of rapid turnaround, they are going to have to radically change how rocket and payload integration is done. Maybe they are already working on that. I don't know.

Airplane designers have to put a lot of work into making sure this sort of thing can happen without conflicts:

Edited August 28, 2020 by mikegarrison

[CatastrophicFailure]

 

 

 

[Elthy]

Regarding testing vacuum engines in normal atmosphere:

This is how they do it. If i understand that correctly the engine exhaust "sucks out" ambient air from the diffuser, creating a lower pressure within. The picture from one of the coolest blogs ive ever read: https://blogs.nasa.gov/J2X/

Sadly the J2X engine was shelved among the clusterlove of SLS developement...

Edited August 28, 2020 by Elthy

[sevenperforce]

2 hours ago, CatastrophicFailure said:

Whoa.

They only need TWO ENGINES to do hop tests for Superheavy.

2 hours ago, CatastrophicFailure said:

Is this the first regeneratively-cooled vacuum nozzle? Other than the SSME, which was an altitude-compensating nozzle.

[DDE]

4 hours ago, mikegarrison said:

Cranes don't usually need to survive the environment of being directly next to a launching heavy-lift rocket.

Note the object on top:

Granted, it would turn away by quite a bit:

[mikegarrison]

17 minutes ago, DDE said:

Note the object on top:

Yes, a rocket program noted for its successful safety record!

[RCgothic]

Wow, they're actually going to try and go for it (20% cumulative chance of acceptable weather and range availability notwithstanding!)

 

Edited August 28, 2020 by RCgothic

[Elthy]

Do i understand correctly that the SAOCOM 1B booster will land at LZ-1 and the one from Starlink on the barge?

[derega16]

2 hours ago, Elthy said:

Regarding testing vacuum engines in normal atmosphere:

This is how they do it. If i understand that correctly the engine exhaust "sucks out" ambient air from the diffuser, creating a lower pressure within. The picture from one of the coolest blogs ive ever read: https://blogs.nasa.gov/J2X/

Sadly the J2X engine was shelved among the clusterlove of SLS developement...

I still don't understand why they choose cluster of dinky RL-10s instead of J-2X for EUS. For make it different from Ares?

Edited August 28, 2020 by derega16

[borisperrons]

On 8/25/2020 at 1:17 PM, magnemoe said:

An aircraft carrier is probably too small and wrong designed you are not putting 5000 ton at the front or the back of a ship and then suddenly remove it. 
An nuclear powered  aircraft carrier is also very expensive to run as its an large warship. 

If they make an offshore installation I would use an series of oil platform like structures on legs to the ocean floor, one as an launch pad, one as an landing pad, one who is hangar for refurbishment, payload integration and storage. This could be integrated with landing pad as in land on the roof but using an separate platform might be easier. You also need fuel storage, oxygen storage and production crew quarters. 
Latest is an issue as even if you spread this out a bit its no way you can armor it against an kiloton blast, putting the bunker underwater might work. 

The Italian Space Agency did have something similar, a refurbished drilling platform to launch Scout rockets from out of the Kenyan coast:

That being said, there's actually no shortage of unused floating drilling platforms right now. I think at least 6 are mothballed in the Firth of Forth in Scotland. I can see them repurposing some for use as launch platforms as Sea Launch did.

As for the launch crew it's actually easy, you just put them on a boat the GTFOes out of the danger zone when is launch time.

[mikegarrison]

1 hour ago, RCgothic said:

Wow, they're actually going to try and go for it (20% cumulative chance of acceptable weather and range availability notwithstanding!)

 

I thought there were range conflict issues involved. Something about the fire department and water supply not being big enough to handle supporting multiple launches per day, or some such thing.

[CatastrophicFailure]

1 hour ago, mikegarrison said:

I thought there were range conflict issues involved. Something about the fire department and water supply not being big enough to handle supporting multiple launches per day, or some such thing.

IIRC they need like 14 hours of recycle time between launches, so if DIVH goes toward the start of its window it might still happen. 

[tater]

 

[Guest]

3 minutes ago, tater said:

 

Sweet! Can someone clarify to me when we should start expecting stacking on the Superheavy?

[Ultimate Steve]

4 minutes ago, The Doodling Astronaut said:

Sweet! Can someone clarify to me when we should start expecting stacking on the Superheavy?

We don't know for sure, but if they want to optimistically have it hopping in October, we should see it start in the next week or two IMO (not an expert). The high bay is nearly done (on the outside at least) so there's not much stopping them from starting.

[Guest]

1 minute ago, Ultimate Steve said:

We don't know for sure, but if they want to optimistically have it hopping in October, we should see it start in the next week or two IMO (not an expert). The high bay is nearly done (on the outside at least) so there's not much stopping them from starting.

My guess is going to be 3 times that. Which statistically speaking is about how far things are from what Elon promises SpaceX wise. So big bets by February. That also lines up from what he said last year times three. I am guessing orbital flight by June.

[kerbiloid]

7 hours ago, DDE said:

Note the object on top:

Recalling other masterpieces of this team, like the launch tulip, does this crane quickly pulls the rocket up to engage?

[tater]

3 hours ago, The Doodling Astronaut said:

Sweet! Can someone clarify to me when we should start expecting stacking on the Superheavy?

Musk said SH can hop with just 2 Raptors. So we won't even know from seeing the thrust puck necessarily. I assume they will do SN8 with more than 1 Raptor? If so, that's not only the skydiver test, but tests 2 engines for a SH hop.

[AVaughan]

40 minutes ago, tater said:

So we won't even know from seeing the thrust puck necessarily.

I would expect that the thrust puck (and the thrust simulator during tank tests) will need to be significantly heavier to handle the loads for a superheavy with 30+ sea level raptors.  Of course they could build a test superheavy with a starship thrust puck for a quick test hop, but I don't really see the point, (unless they are in a rush to build a super heavy for publicity reasons).  

(Also if super heavy still has 7 gimballed engines in the center, then I would expect that to be a central engine, plus 6 surrounding engines.  Shouldn't that arrangement result in a visibly different thrust puck from starship?)