totm nov 2023 SpaceX Discussion Thread

[tater]

 

[tater]

 

[KSK]

1 hour ago, darthgently said:

The bread truck full of bread is the hundreds of successful launches and landings in the books with F9 and FH.  We have our bread today.  Not sure what you mean.  You'd prefer Musk be on Bezo time?

The recipe seems to be working quite well

To be perfectly honest, I don’t much care if we’re on either - and I don’t recall mentioning Bezos at all, so the point is moot.

But what I meant is that, whilst IFT was impressive and a big step forward over IFT2 and IFT1, there’s a way to go yet before it’s a workable disposable rocket, let alone the fully reusable, chopstick  landing (or whatever method ends up working), in-orbit refuelling, Artemis landing beast that it’s intended to be.

Yes, yes, test flight, iterative improvement etc etc. I’m well aware of all that. And, with their track record,  I’m certainly not betting against SpaceX to deliver all of the above eventually.

But what I don’t give a damn about is Elon vapourware about the next super-duper-double-the-payload rocket, because it doesn’t make much difference if your rocket carries 200 tons or 400 tons if you can’t get it to point the right way.

Frankly it feels like a distraction tactic and judging by the shift in comments on this  thread it’s worked beautifully.

 

 

[sevenperforce]

4 hours ago, Exoscientist said:

Keep in mind such an expendable launch is only in the $90 million cost range. While not at the $10 million aspirational rate Elon wants for full reusability,  considering the amount of payload it could loft, it still would be a major improvement over what we have now, and literally orders of magnitude cheaper than the SLS. 

I don't think anyone is dispute that using Starship is better than using SLS for...well, basically anything.

4 hours ago, Exoscientist said:

By the way, suppose as a SpaceX exec once suggested the Starship HLS would need “10ish” orbital refuelings. At the $10 million per launch rate for a fully reusable SH/SS that’s still $100 million. Then the single launch expendable approach would actually be in the same cost range as the fully reusable approach, anyway.

A single-launch architecture could certainly have cheaper launch costs than the current planned Starship HLS, but that would require that Congress and NASA pursue a lunar mission profile that avoids SLS entirely, and they evidently don't want to do that.

You'd also need to dev a lunar lander and a crew vehicle that would fit on top of an expendable Starship. The amount of time that it would take to rework Orion for a single-stack launch architecture is...prodigious.

[tater]

38 minutes ago, KSK said:

But what I don’t give a damn about is Elon vapourware about the next super-duper-double-the-payload rocket, because it doesn’t make much difference if your rocket carries 200 tons or 400 tons if you can’t get it to point the right way.

I don't see it that way in the least. V2 is coming soon anyway, and all V3 is is a stretch. V2 has been known for a while now—he said that the ships waiting to fly are the last V1, they are calling the next ones V2 that incorporate what they've learned so far. I assume V2 parts are in the buildings already. Adding a few rings is hardly "vaporware."

Found it:

 

 

[Meecrob]

15 hours ago, Superluminal Gremlin said:

I would like to propose the possibility of the sem-failure of the final booster relight. The tanks were not fully loaded, even at launch, so there may not have been enough fuel to create a nice, clean, no-gas relight. Of course, those oscillations didn't help.

 

They mess around every test-flight. They knew it was going to fail. They want to see how their redundancy systems handle the failure. As @mikegarrison said abive, its just standard engineering.

[tater]

 

Assume the 4 more are 29-32 unless 32 is getting scrapped. Everything past 32 is V2. Any stretched version is V3—and they stated a while ago that more work by the ship vs booster in on the long term plan (stretched ship).

[Flavio hc16]

8 minutes ago, tater said:

 

Assume the 4 more are 29-32 unless 32 is getting scrapped. Everything past 32 is V2. Any stretched version is V3—and they stated a while ago that more work by the ship vs booster in on the long term plan (stretched ship).

And of the 4 V1 Ships, probably we will see only another 2 fly by my guess, the other 2 will be scrapped and they will start to fly the ships v2

[Hotel26]

11 hours ago, KSK said:

More prosaically, I'd prefer bread today than jam at some unspecified Elon Time tomorrow.

May 1961, JFK set a decade-long goal to do something never before done by mankind; only ever dreamed about.  It was achieved but not in his own lifetime.  The vision and the result inspired and energized the whole world.

Today we live in a collective hive-mind world.  Visionaries, especially billionaires who have the wherewithal to drive their own ideas forward, are hated and reviled by little thinkers.

Edited March 16 by Hotel26

[darthgently]

57 minutes ago, KSK said:

To be perfectly honest, I don’t much care if we’re on either - and I don’t recall mentioning Bezos at all, so the point is moot.

But what I meant is that, whilst IFT was impressive and a big step forward over IFT2 and IFT1, there’s a way to go yet before it’s a workable disposable rocket, let alone the fully reusable, chopstick  landing (or whatever method ends up working), in-orbit refuelling, Artemis landing beast that it’s intended to be.

Yes, yes, test flight, iterative improvement etc etc. I’m well aware of all that. And, with their track record,  I’m certainly not betting against SpaceX to deliver all of the above eventually.

But what I don’t give a damn about is Elon vapourware about the next super-duper-double-the-payload rocket, because it doesn’t make much difference if your rocket carries 200 tons or 400 tons if you can’t get it to point the right way.

Frankly it feels like a distraction tactic and judging by the shift in comments on this  thread it’s worked beautifully.

 

 

All companies selling a product talk about future plans and future products that may not be realized yet.  You have noticed what site you are posting this on I presume.  Ironic.  Seems strangely obsessive to call it "Elon vaporware" as if this kind of public announcement never happened before he came along.  Why not call it "Star Theory vaporware"?   We could go through all the only-on-paper rocket plans from the big space industry players over the last half century also I suppose, but we have a siblings forum devoted to that so I won't.

As for the pointing, no one has tried to maneuver such a large craft at those temperatures with could gas thrusters before that I'm aware of.  The volume of gas emitted was likely unprecedented.  They likely froze over.  I bet they fix the problem and  make public announcements about the next design at the same time as easily as a kid chews gum and rides a bike at the same time. 

The stated goals of the test flight were met.   Anything else would have been gravy.  A suborbital trajectory was a precaution taken specifically for a situation like that which occurred with the thrusters; there was no danger of it remaining in orbit as a hazard.  They have rockets lined up like kids at a roller coaster.  I don't see any problem.  It's working.

[PakledHostage]

Do we know anything about the performance that they're actually achieving? They've succeeded in getting a mostly empty,  50 metre long shell into a sub-orbital trajectory, but so did the Space Shuttle. Of course the Space Shuttle's main tank was never meant to reach orbit and Starship is supposed to eventually be able to fill a lot of that empty space with heavy cargo, but how much? Are they achieving their goals?

For example, it sounds like the exhaust deflector that was added to the booster to allow hot staging was massively heavy. How much did that impact payload performance? We all know from playing KSP that "the tyranny of the rocket equation" is real... and that's just one example of the payload performance hits that they've had to suffer to make the thing work.

What sorts of payloads are they actually going to be able to achieve,  after all the dust settles?

[darthgently]

1 hour ago, KSK said:

Frankly it feels like a distraction tactic and judging by the shift in comments on this  thread it’s worked beautifully.

Maybe that is part of the recipe that is winning the ribbons. 

Would most of us still be here in this forum if information about KSP2 had never been announced again after the first announcement years ago and KSP1 were the end of the line, bugs and all?  As it turned out, KSP2 was hyped, we all hung around, and eventually it released.  Musk is announcing future plans to keep interest and excitement up.  And frankly, SpaceX has met stated timelines at least as well, if not better, than KSP2 did.  With real rockets.

[KSK]

27 minutes ago, Hotel26 said:

May 1961, JFK set a decade-long goal to do something never before done by mankind; only ever dreamed about.  It was achieved but not in his own lifetime.  The vision and the result inspired and energized the whole world.

Today we live in a collective hive-mind world.  Visionaries, especially billionaires who have the wherewithall to drive their own ideas, are hated and reviled by little thinkers.

love you too, buddy.

[tater]

8 minutes ago, PakledHostage said:

What sorts of payloads are they actually going to be able to achieve,  after all the dust settles?

Highest F9 payload mass fraction to date (with landing) is 3.19%.

If Starship can get 2% with full reuse, that's 100t.

F9 claims 4.3% expended, so for SS/SH that would be 216t.

41 minutes ago, Flavio hc16 said:

And of the 4 V1 Ships, probably we will see only another 2 fly by my guess, the other 2 will be scrapped and they will start to fly the ships v2

Certainly possible. Depends on what they learn in the next few flights. If they get V1 dialed in, then they likely skip to the V2s that will already be waiting.

And another launch

 

[PakledHostage]

1 minute ago, tater said:

If Starship can get 2% with full reuse, that's 100t.

Right, but adding significant empty mass to the booster will impact that "if". The original idea didn't involve hot staging, but when that didn't work on IFT-1, they added the exhaust deflector. I recall seeing in the CSI Starbase video below that the deflector has as much mass as an empty Falcon 9 booster. Adding that much has gotta smart...

 

 

[darthgently]

5 minutes ago, PakledHostage said:

I recall seeing in the CSI Starbase video below that the deflector has as much mass as an empty Falcon 9 booster. Adding that much has gotta smart...

The rocket eqn does show a little more mercy on the first stage at least, but you make good points.  Don't forget the added tank baffles either.   I'm guessing this is one reason to keep squeezing more performance out of Raptor; to get some headroom in case things like this add up, they have some headroom.  Idk

[tater]

25 minutes ago, PakledHostage said:

Right, but adding significant empty mass to the booster will impact that "if". The original idea didn't involve hot staging, but when that didn't work on IFT-1, they added the exhaust deflector. I recall seeing in the CSI Starbase video below that the deflector has as much mass as an empty Falcon 9 booster. Adding that much has gotta smart...

~10t. out of ~5000t

[Meecrob]

7 hours ago, KSK said:

How about getting this rocket consistently pointing in the right direction first

Realize they only completed the necessary amount of launches to confirm a trend with three. Which direction is that trend going?

[Meecrob]

1 hour ago, PakledHostage said:

Do we know anything about the performance that they're actually achieving? They've succeeded in getting a mostly empty,  50 metre long shell into a sub-orbital trajectory, but so did the Space Shuttle. Of course the Space Shuttle's main tank was never meant to reach orbit and Starship is supposed to eventually be able to fill a lot of that empty space with heavy cargo, but how much? Are they achieving their goals?

For example, it sounds like the exhaust deflector that was added to the booster to allow hot staging was massively heavy. How much did that impact payload performance? We all know from playing KSP that "the tyranny of the rocket equation" is real... and that's just one example of the payload performance hits that they've had to suffer to make the thing work.

What sorts of payloads are they actually going to be able to achieve,  after all the dust settles?

No, they designed the hot-swappable hot staging ring while they made the illusion of attempting that rotational separation dealie. They transitioned over to the hot staging once they got to the newer starship because the weight savings on that version outweighed the hot staging ring.

[tater]

And I ran out to the store and missed the launch:

 

 

[PakledHostage]

1 hour ago, tater said:

~10t. out of ~5000t

[tater]

Added mass to the booster is not that big a deal for a LEO rocket.

back of the envelope I see a ~20 m/s difference with an added 10 tons at staging—and the total dv I'm seeing is way higher than staging velocity. That added mass on the ship would be taking out payload 1:1, though.

[AckSed]

Does the Superheavy take a lofted trajectory, and would that make a difference to any added tonnage from safety features? Because Eager Space makes the argument that F9 already pushes the bulk of the work onto the second stage, and if you're designing reuse from the start, then optimising for a lofted trajectory decreases the energy needed for the boostback burn in RTLS:

https://www.youtube.com/watch?v=zQp9UdppD-4

 

[tater]

9 minutes ago, AckSed said:

Does the Superheavy take a lofted trajectory, and would that make a difference to any added tonnage from safety features? Because Eager Space makes the argument that F9 already pushes the bulk of the work onto the second stage, and if you're designing reuse from the start, then optimising for a lofted trajectory decreases the energy needed for the boostback burn in RTLS:

https://www.youtube.com/watch?v=zQp9UdppD-4

On one of the interviews Musk said that the booster is currently doing too much, and hence they want to stretch the ship. I think. Maybe I'm remembering wrong.

[DAL59]

I have a really stupid idea, whats the mass of the Blue Origin lander fully fueled? Could the easiest Artemis architecture just be putting the Blue Origin lander on a lunar trajectory with an expendable Starship launch?