CBase

So how is stage seperation actually supposed to happen ? Both regarding movement and release structure. I can't remember if some pictures showed the connections between SH and SS. I have read something like a spin release, but that would indicate a substantial different stage connection than traditional decouplers.

After some slow motions thrust below pad seamed to build up normal, the delay between cameras was just very high. However there are flames coming from above, which might have been HPU

Actually I have a feeling stress on launch pad was anormal already. They did spin up quite early and long and then after ignition there was rather some detonation than reflected thrust. I noticed in the NASA Specaflight video that flames where way faster upwards than transmission from other cam

Flight termination

failing

5 engines missing...not too bad

countdown

staying at T-0:40 it seams

Go go go

Since it got a little bit lost into some discussions: SpaceX targets today another attempt ! A little surprising as I thought the TFR was cancelled.

Was posted yesterday, but actually more likely today, Friday. I do think the timing is intentionally: FAA license before Weekend, Monday first try. There have been rumors about enviromental groups trying to stop any FAA license once it is issued. Even filing a TRO will be hardly possible within this time frame (getting full text, find issue, file documents, ...).

Sounds abstract, but might be interesting for heat shielding as non periodic patterns have no continuous gap in any direction: https://phys.org/news/2023-03-geometric-tiled.html Might just prove hard to bend, but noone said rocket engineering is easy

Thank you @Arugela for provoking @sevenperforce great explanation into air fed engines

Current downrange placement of the barge is ~300km from launch site. Even if it can be spread significant with a different profile, a ring around earth would require 20 or even more launch sites, some located far out on the ocean. I didn't think so far ahead, but you are right, once we are a spacefaring civilization a closed network of launchsites makes sense. But for the next 5 or even 10 years Elon will need an intermediate solution to drive up space business with SS/SH.

I guess dv loss is too big for ping pong between a land and offshore site as at least launch would be against earth rotation. And then there is of course the logistic challenge to deliver payloads to the offshore site, additional crew for integration etc. Oh and of course SH and SS would need to land at the offshore plattform to actually use it for orbital launches. Actually I like the SH refill and fly back story: it provides quite some additional payload over RTLS with minimal requirements for the offshore platform. Again I doubt it for the logistics reasons and costs to maintain so many ground based facilities.

the question is how pure: as I understand it, the tricky part is seperating C60 from C70, C72, ... but does it matter that much for an ion thruster ? And even if you loose some efficiency and thrust, as long as you are better than xenon who cares ? So actually a quite kerbal idea

I am not sure about this. The huge amount of open data from SX keeps raising the bar for all competetor's. Moving targets, changing requirements to keep investors happy do not benefit competetor's development projects. A couple of rocket startups scrapped small scale projects just to go "all in" with bigger ones. Maybe they just skipped commercially irrelevant products, maybe the skipped cheap lessons on required knowledge.

They are currently on the ridge of wasting millions because the leaked hydrogen kills several certified limits. And you are afraid of loosing a fan ? I mean with 2 billion per launch and only a handful of launches I am not sure that building pipes would ever pay off. This is the very difference between SpaceX and the rest: Good enough let's you focus on the next challenge. Optimise later.

The problem is not leaked hydrogen, but increased concentration in the air around the rocket and associated fire risk. Wouldn't a constant airflow around the valve prevent the fire risk ? So just putting something like this near the leakage ?

The problem ist really more about slow turn around: failing is painfully slow until they are ready for another attempt. WDR or ground problems pushed the schedule by months. And because they do, they try to skip some only to later learn that it was needed. pushing it even further. I mean the WDR tests did not any alignment with launch windows if they were planned as it. Being on schedule on any innovative project is really a lot about failing softly.

Did I missed something or had SX sent out 3 static fire warnings in a row without any testing taking place, substantial action around the test points or comments ?

Develop by Airbus: For sure ! Contract by JSAT with delivery in 2024 at a time when not any of them had even a prototype ? I doubt it. JSAT is not a venture founded silicon valley company where it is normal to bet millions on optimistic proposals. I wouldn't even be surprised if SX used FH as insurance to meet the customers timeline if starship is not yet ready.

I could not find any specifications for the Superbird-9 regarding mass or size, but according to Ars Technica: Com sats are pretty big, but it seems unlikely that JSAT and Airbus contracted something in 2021 that could not be transported by any commercial rocket.

Are there any serious numbers out there how much mass you actually save from any high altitude launch (20km+) ?

If you read the article above SpaceX has the habbit of actually changing flight parameters constantly to find the optimal ones. Having engines max thrust increase certainly gives them more room to experiment with. Although quite likely it doesn't mean they will use the maximum thrust or duration of maximum thrust might be more limited than for falcon 9. Actually starship has already a pretty decent TWR, so efficency gains from using more thrust will propably be weighted against wear and tear.