SpaceX (Vol. 2)

[2fast748]

Eric Mc said:

Arnold Cunningham said:

Did it have enough spare thrust/fuel to actually carry any worthwhile cargo?

Exactly. Just getting the rocket to work is one thing. Getting the rocket to do all the things they hope it will do seems an awfully long way off.

There's a bit of "cope" going on on SpaceX Twitter. Now backtracking on how quickly it will be re-used, talk of Space Shuttle level cadence. Integrating payload is currently being discussed as "Too complicated to rush..."

[Beati Dogu]

Relax. It'll be fine.

[Simpo Two]

Eric Mc said:

There is a "fake it 'til you make it" feel about Starship in my opinion.

From what you say it sounds the the rocket version of the Flying Bum: https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_...

[Ian974]

At the moment I'm almost thinking that starship and super heavy need to be considered separately.

The booster (IMO) is looking remarkably capable so far considering the complexity of it and landing process. I've not followed the full details of the booster failure on the last launch, but it was intended to be stressed significantly during return anyway?

Starship with 6 engines does appear (currently) to be having much more significant system issues with the engines than the 33 on the booster, I understand the concern about reliability with more engines and complexity, but I don't think too many engines is the main issue playing out.

Gut feeling for me is even if they end up having to look at redesigning starship from scratch or possibly going to smaller multi stages, the booster itself is likely to become a very reliable first stage.

[kevinon]

Simpo Two said:

From what you say it sounds the the rocket version of the Flying Bum: https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_...

I'm not making a direct comparison between the man who built the Titanic sub, and Elon.
But as I read the review of the Netflix doc on the sub, covering the 10 years of development and inside testing, I could discern some echoes of the mindset at SpaceX. Big ballsy 'mission'; and a fail fast and break thins ethos.

IANA Rocket scientist, and I confess I am interested in the psychology of it, not the nuts and bolts, but you guys may have a thought.

https://www.theguardian.com/film/2025/jun/11/titan...

[annodomini2]

Simpo Two said:

Hill92 said:

RumbleOfThunder said:

I always thought (with zero expertise) that simply using 33 raptor rocket engines instead of 5 or so large engines was not the way to go.

That decision is driven by 3 factors crucial to SpaceX philosophy:

1. Multiple smaller engines allows deeper, more precise throttling and finer gimbal control of the overall rocket for retropropulsive landings.

2. Increased redundancy and reliability for rapid reusability.

3. The Raptor engines are designed for mass production.

That means the rocket is designed first and foremost to be reusable, not to complete its mission. And they've succeeded...

The demand for reusability looks like the problem.

Large engines have their own issues, all the F1 engines for the Saturn V's had to be individually tuned on the test stand.

You basically run into material strength issues.

The main problem is they are pushing the boundaries of the technology and have not (yet) achieved their desired performance goals.

[Arnold Cunningham]

kevinon said:

I'm not making a direct comparison between the man who built the Titanic sub, and Elon.
But as I read the review of the Netflix doc on the sub, covering the 10 years of development and inside testing, I could discern some echoes of the mindset at SpaceX. Big ballsy 'mission'; and a fail fast and break thins ethos.

IANA Rocket scientist, and I confess I am interested in the psychology of it, not the nuts and bolts, but you guys may have a thought.

https://www.theguardian.com/film/2025/jun/11/titan...

Differrence between the 2 is that Space X is externally monitored both by their customers (ie. NASA) and the FAA.
Moreover, Titan proactively refused to work with DNV (certificiation authority) and didn't even get many of the basics right (people who were good didn't stick around for long).

So I don't think they are the same. I think titan was an ego "I know better than you and don't care what you think". Vs Space X who I think have hired the smartest in the business and have intentionally pushed boundaries, perhaps this time without adequate success.

And Space X aren't trying to fly paying customers on their as yet unproven, uncertified rocket.

I really do want Space X to succeed from an engineering perspective. I fear that if they don't make it work, the next round of engineers will look at it all as an abject failure and future designs will be derivative rather than innovative.
Obviously what I want doesn't really factor in to it all though, but the negative impact on space exploration and innovation could be fairly profound. Or hopefully Elon can afford to keep funding development, even if that's a rethink from scratch based on lessons learnt, until it does work...

Edited by Arnold Cunningham on Thursday 12th June 14:31

[Eric Mc]

I think Starship CAN be made to work - but the fly-crash-modify, fly-crash-modify etc etc technique may turn out to NOT be the best way of sorting it out.

[Arnold Cunningham]

Eric Mc said:

....but the fly-crash-modify, fly-crash-modify etc etc technique may turn out to NOT be the best way of sorting it out.

Agreed. I've actually just completed a Design Search & Optimisation course, run by Professor Andy Keane that covered many of these aspects. If anyone has interest in how to design and optimise things, both his experience & his course are excellent.

[kevinon]

I've looked up the course Arnold.

Wow. -big brains. Good to know about the background to your knowledge.

[Beati Dogu]

This is launch pad 37 at Cape Canaveral



Former home to Saturn 1 & 1B rockets in the 60s and latterly the home of Boeing/ULA's Delta IV and Delta IV Heavy.

The last one of those flew from here in 2024, so it has since reverted over from ULA to US Space Force control. There are proposals to revamp it for major Starship operations once the relevant permissions & permits have been accepted.

And if you think they're not serious about it, well the umbilical tower, vertical assembly tower and lightening towers were dropped today using explosive charges:

https://x.com/SpaceflightNow/status/19331756289558...

[Simpo Two]

annodomini2 said:

The main problem is they are pushing the boundaries of the technology and have not (yet) achieved their desired performance goals.

It's an interesting thought. Do you set a performance goal to be within known technology, or beyond it and hope you can bridge the gap before the money/patience/laws of physics run out?

[Eric Mc]

The Axiom 4 manned mission to the ISS has been postponed indefinitely. During the prelaunch tests a few days ago an oxygen leak was discovered in the fuel system.

SpaceX aren't having a lot of luck at the moment.

Edited by Eric Mc on Friday 13th June 09:48

[Arnold Cunningham]

Simpo Two said:

It's an interesting thought. Do you set a performance goal to be within known technology, or beyond it and hope you can bridge the gap before the money/patience/laws of physics run out?

The debate is not so much about pushing technology, but how best to push. It all comes down to "experiment design" and the "cost of experiment". In research you want to design experiments where the cost (cost isn't just £, it can be time, or any valued commodity you consume) is low and the data you get is high.

So running starhopper - comparitively low cost, comparatively high data. Running starship - very high cost. So good engineering practice looks for ways to maximise the data you get for minimal cost - which isn't just keep launching it with your fingers crossed.

I am sure there's an awful lot of maths (not math unless you say mathematic) also going on behind the scenes, and perhaps genuinely each failure is a new one - but that just suggests the experiment design is wrong. IMVHO.

[Beati Dogu]

They launched the 500th Falcon 9 today. The booster landing safely for its 15th time.

[bobthemonkey]

Eric Mc said:

The Axiom 4 manned mission to the ISS has been postponed indefinitely. During the prelaunch tests a few days ago an oxygen leak was discovered in the fuel system.

SpaceX aren't having a lot of luck at the moment.

Edited by Eric Mc on Friday 13th June 09:48

But also pushed back at the request of NASA while they investigate a worsening (or new) leak on the Russian side.

https://arstechnica.com/space/2025/06/theres-anoth...

[Ian974]

Arnold Cunningham said:

The debate is not so much about pushing technology, but how best to push. It all comes down to "experiment design" and the "cost of experiment". In research you want to design experiments where the cost (cost isn't just £, it can be time, or any valued commodity you consume) is low and the data you get is high.

So running starhopper - comparitively low cost, comparatively high data. Running starship - very high cost. So good engineering practice looks for ways to maximise the data you get for minimal cost - which isn't just keep launching it with your fingers crossed.

I am sure there's an awful lot of maths (not math unless you say mathematic) also going on behind the scenes, and perhaps genuinely each failure is a new one - but that just suggests the experiment design is wrong. IMVHO.

I suppose that there is added complication with this system that anything they're producing they're also needing to work out a volume manufacture method for at the same time.
It's quite surprising how quickly they've been building, taking down and rebuilding the different assembly bays in Texas.

Devils advocate, there are perhaps already fixes available for (some) of the flight issues they've had, but not in a way that's compatible with the build methods/ volumes they're planning on?

[Arnold Cunningham]

Agreed, but, generally you design what you want and then work out how to make it. Sometimes you then adjust the design based on what it's possible to make or how much it costs. No idea what Space X have been doing though.

[annodomini2]

Simpo Two said:

annodomini2 said:

The main problem is they are pushing the boundaries of the technology and have not (yet) achieved their desired performance goals.

It's an interesting thought. Do you set a performance goal to be within known technology, or beyond it and hope you can bridge the gap before the money/patience/laws of physics run out?

They'll simulate it, determine the theoretical, ideal maximum, then build and test.

Maybe they were overly ideal with their models.

Most of it is around fuel/oxidiser ratio, they typically run fuel rich to manage temps in the combustion chamber.

Closer to Stoichiometric they can run the more thrust they'll get, but higher temps.

Rocket engines are always how hot can you run it, without melting the engine.

[Beati Dogu]

Future Starship? pad 37 at the Cape, after the recent demolition



Despite the numbering it’s basically next door to their existing workhorse pad at SLC-40.