totm nov 2023 SpaceX Discussion Thread

[stephensmat]

24 minutes ago, SunlitZelkova said:

I don’t think the alarm needs to be sounded here. Starship-Superheavy’s development might look a little like the R-7, Proton, or even F9 landing attempts, but eventually it will succeed- like all those other rockets did.

The Falcons had plenty of failures too; they were just easier to build and launch.

SpaceX has a surprisingly Kerbal-like philosophy: Try. Fail. Fail Better.

It's been an interesting week for people who follow these things. NASA has admitted SLS isn't going to work, and Starship is ready for the next test flight.

[Exoscientist]

9 hours ago, tater said:

Full flight static testing is useless. Having it blow up in a test stand is unquestionably worse than having it do so 40km up.

 Yep, the Apollo guys building a separate static test for all the engines took a useless approach. Better to follow the Soviets N-1 approach.

   Robert Clark

Edited September 9, 2023 by Exoscientist

[tater]

13 minutes ago, Exoscientist said:

 Yep, the Apollo guys building a separate static test for all the engines took a useless approach. Better to follow to Soviets N-1 approach.

They could simply take land. They had endless money. They could afford to build things, move them, test them, move them, etc. SpaceX cannot possibly do this. They would have to build a rocket factory near the not-Boca Chica test site (they are given limited test days), then they would test a rocket—that would never fly. Having done a test fire on Super Heavy Mississippi (Stennis)—after spending a mint on a test stand capable of 2X the thrust of Saturn, plus another Star Factory—they would know that the rocket built THERE survived. Then they still have to build a new one in TX to fly.

It's worth noting that the Apollo contractors tested to avoid building excess stages. Blowing up a Saturn V would result in schedule risk. You can't look at Apollo out of context. They had different incentives. SpaceX has multiple boosters just waiting for their turn. They have no reason not to send them. The cost of those is already sunk—they lose nothing at all by launching them, in fact it saves the labor of breaking them down for scrap. The only loss for the already built ships/boosters is if a test flight shows data that drives a resdesign. Other than that? Send it.

All the Raptors have been static fired, BTW. Many for full duration that we are certain of, and all for longer than 5 seconds (McGreggor tests are not that short).

Full duration testing tells them how all the engines firing at once at sea level would do for a little less than 2 minutes—when in flight they never fire that long at sea level.

 

Edited September 9, 2023 by tater

[tater]

 

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[tater]

Wonder when they go? SpaceX needs to close the 63 items they presented to FAA, then FAA needs a little time to write the license. Last flight they got the license around 2 days before flight (or was it 2 days before they announced the date?)?

NASA WB-57 calendar has not been updated in a while, they still have the OSIRIS-REx support starting the 28th, and it's the 24th—so I would expect it before the 24th, or after that maybe.

[CBase]

30 minutes ago, tater said:

they still have the OSIRIS-REx support starting the 28th, and it's the 24th

, I see OSIRIS-REx support from 21th to 25th: https://airbornescience.nasa.gov/aircraft_detailed_cal/2023-09?aircraft_id=36

Assuming they plan at least 3 days in a row for weather and other issues, they would need to be ready by 18th september or in 9 days. I doubt that. From 26th of october there are 8 days of support as placeholder. Way later than expected, but would be realistic.

 

Edited September 9, 2023 by CBase

[tater]

15 minutes ago, CBase said:

, I see OSIRIS-REx support from 21th to 25th: https://airbornescience.nasa.gov/aircraft_detailed_cal/2023-09?aircraft_id=36

Oh, you're right, the day dividers are odd, and I shifted it down one row in my head!

[CatastrophicFailure]

All 63 requirements have either been completed or are for future flights…

 

also 90+ cameras. 

[AckSed]

That's a lot of data.

[darthgently]

11 minutes ago, AckSed said:

That's a lot of data.

That is what starlink is for, right?  90+ cameras!  A few on the fairings also.

[JoeSchmuckatelli]

Any chance they light the candle this week?  (I'll stop class to show it) 

[tater]

9 minutes ago, JoeSchmuckatelli said:

Any chance they light the candle this week?  (I'll stop class to show it) 

I imagine we get a couple day warning at least.

[JoeSchmuckatelli]

17 minutes ago, tater said:

I imagine we get a couple day warning at least.

Yeah... I agree - but I don't follow this closely enough to even speculate what the tweet is telling us. 

(I rely on you experienced diviners for that!) 

Thanks! 

[tater]

I will probably get a text at some point that NASA is expecting it on a particular day—which I will post assuming the text doesn't have a "shhhh!" added to it, then I have to just wait.

[RCgothic]

On 9/9/2023 at 2:09 AM, RCgothic said:

The vehicle's already been redesigned. Check. Send.

 

8 hours ago, CatastrophicFailure said:

All 63 requirements have either been completed or are for future flights…

 

also 90+ cameras. 

[CBase]

9 hours ago, CatastrophicFailure said:

All 63 requirements have either been completed or are for future flights…

Nice stunt

[tater]

It's important to remember that all the checklist items came from SpaceX since the FAA knows effectively nothing about SS/SH at the detail level required to make engineering changes. SpaceX, FAA (and I think NTSB?) are all CCed on the comms as I understand it. FAA is sort of supervising the effort of SpaceX, in short. SpaceX shows them they are doing due diligence on ascertaining the causes of various failures (and also in identifying them in the first place), then proposes fixes (presumably with a rationale for each fix as to how it relates to failure modes). They then show they are done implementing changes... then send it.

[Spaceception]

Wen launch?

This sounds pretty promising for a license in the near future though, with a launch attempt within a week or so if IFT-2 has a similar timeline as IFT-1. The license then was given 3 days before the first attempt.

[tater]

 

[tater]

SpaceX is targeting Monday, September 11 at 11:57 p.m. PT (06:57 UTC on September 12)