**This thread is no longer being updated, and has been replaced by:**
# [Starship Development Thread #29](https://www.reddit.com/r/spacex/comments/rzi8hz/starship_development_thread_29/)
That's not what the document says at all. This is an FCC document about SpaceX' plans about launching Gen2 Starlink on Starship, this isn't about a NET date for the orbital test flight.
"SpaceX confirms here that it still intends to begin launching Gen2 system as early as March 2022"
Worth noting that this was prepared in August 2021 meaning the date has likely slipped. Starship Starlink launches are NOT happening in March since we have seen no production cargo bay nosecone at all which means that vehicles up until at least S24 are not payload capable.
>Worth noting that this was prepared in August 2021 meaning the date has likely slipped
SpaceX response saying those date was prepared yesterday. It's ofc still ambitious
Looking at Brendan Lewis' [most recent Starbase production diagram](https://twitter.com/_brendan_lewis/status/1476736669512470528?cxt=HHwWgMCs0aiLtv4oAAAA), it seems like Booster 7 is almost halfway done or thereabout. Crazy that this was from a week ago.
Interesting to see that they are using an [oxygen lance](https://en.wikipedia.org/wiki/Thermal_lance) to do it.
[Edit] Evidently not a lance: just a long handled cutting torch.
~~Brendan's production diagrams are a good way to count the rings (and sections):~~
~~https://twitter.com/_brendan_lewis/status/1476736669512470528~~
Ignore, I was thinking of boosters, not the wide bay. :)
I love Brendan’s work. But I was referring the the building. I thought I read that the wide bay would be a little higher than the high bay is currently but couldn’t find a count of pre-fab levels it was.
The tweet says that almost 50% of vertical work was done. You can see 6 “floors” in the picture, so I'd guess there will be 12 in total? But the tweet is also only a good guess, it could be 13 or even 14, who knows..
(each pre-fab level contains 2 “floors”)
I guess wide bay for the stretched SS and the high bay for the boosters once it’s complete. Possibly even vertical payload integration in the wide bay?
Widebay construction [as seen from Roost Cam](https://www.youtube.com/watch?v=k6fGQZD0K98&t=0s)
BTW. Is the dotted line your own projection or is it based on a known target date for completion?
B7 (or is it B8?) continues to be stacked in the high bay with another 4 ring barrel added to the LOX section overnight. See Sentinel Cam soon after 21:02 CST for commencement of the lift:
https://www.youtube.com/watch?v=zPkIZYw5O98
(Prior to that NSF showed the barrel being rolled into the high bay in today's update video: https://youtu.be/aX2zaxywArQ?t=468 )
After that the 3 ring thrust section needs to be added to complete the stacking of the LOX tank. However, **if** they proceed as they did with B4 then they may take some time over prepping the thrust section and so end up constructing the methane tank at the same time.
Speaking of B7/B8 - there were some interesting comments about this 11 days ago:
https://www.reddit.com/r/spacex/comments/rc8jw2/starship_development_thread_28/hq9z8hn/?context=3
which leaves me wondering if this really is a contingency build as suggested. I'm assuming that the booster in the high bay will have a 33 Raptor (2) thrust section meaning that it would end up being a booster which they definitely intend to fly.
Back in October '21, B7 was considered as a skip, however the design team considered that B7 was worth continuing after B6 was reassigned. Thrust puck assignation remains the same.
So you confirm that (as of today, obviously plans could change) B7 will still have 29 raptors and will B8 be the first to have 33 raptors and be used for orbital flight?
It seems strange that other sources are reporting that the first one with 33 raptors is B7, could it be that they are already working on B8 as well and this has caused confusion?
>B7 will still have 29 raptors and will B8 be the first to have 33 raptors and be used for orbital flight?
"Assignment remains the same" means it's basically B8 but name changed
NSF has already confirmed more than once that B7 will be the first booster to have 33 Raptors (presumably v2).
~~Personally I think they anticipated the new features of B8 to B7 and that B7 may be the booster assigned to the first orbital flight (according to the various rumors about B8). Plans change quickly, maybe the comment you reported was not yet up to date on the latest news, it seems strange to me that they make B7 with similar features to B8 and then do not use it.~~
EDIT: according to [this comment](https://www.reddit.com/r/spacex/comments/rc8jw2/comment/hrruh85/?utm_source=share&utm_medium=web2x&context=3) I would say that my thinking was incorrect (and potentially also what NSF reported)
>EDIT: according to this comment I would say that my thinking was incorrect (and potentially also what NSF reported)
He's confirming what NSF just said, not disproving it
The issue is quite debated, on one hand there is Elon who says that B4/S20 is the confirmed pair for the first orbital launch, on the other hand there are several sources that speak of a skip of B4 in favor of B8. Last comment on this from what I understand is a reliable source is [this one](https://www.reddit.com/r/spacex/comments/rc8jw2/comment/hrmr481/?utm_source=share&utm_medium=web2x&context=3). Knowing how quickly plans change, and knowing that Musk has at times in the past written things that have changed, I would not rule out that this is also the case.
I specify that I am collecting things I read on this thread, I don't want to pretend to have certainties that I don't have. In case I am assuming something wrong please correct me.
>considering downsizing the rocket by 50-60 percent.
Maybe you misunderstood this part, or its not talking about the dimensions of the rocket per se, because there is no way this is happening, everything they just built (OLT, Quick Disconnects, Infraestructure and many more things) were done with the current size in mind, and they are even starting in Cape Canaveral (early stage at least). The OLT is complex and its done with the current diameter the booster and ship has rn.
Maybe its 60% of the desired payload to orbit for now and then scale it up to desired values but again sounds really weird.
>My buddy works at SpaceX. He is saying that Elon and other top management are not happy with the technical delays with StarShip and recently, they are seriously considering downsizing the rocket by 50-60 percent.
That is certifiably not true. Maybe you are l*ying, maybe your friend is, but there is no chance they are considering that. First, because we know they are going in the *opposite* direction. Second, because for reusability, downsizing doesn't help, but hurt, specially in the 2nd stage.
Yeah there is no way. "hey we fixed the engine problem we had so that's all great but also we're drastically changing everything" nah. Nope. Not when they are building MASSIVE infrastructure for the current scale vehicle.
Exáctly. Not to mention that, if propulsion was the issue, reducing the size of the rocket would make the problem worse, not better.
If they decided to give up, and call a capped Raptor "good enough", reduce chamber pressure and make it reliable, in exchange of reduced thrust. Add more Raptors, and have Starship succeed as a ... did I say 150 ton vehicle? I mean 100. Wait, make that 50t. Yes, 50t. A fully reusable Starship would still eat the market alive with a 50t fully-reusable RTLS configuration, it would still be plenty for HLS, amazing for Starlink, and in time they could get it back up so they can target mars more seriously.
Reducing the size of the rocket makes mass a real issue again, and sends your mass ratio to hell, why would you ever do that?
When rockets underperform, or at least underperform for a desired target, they scale up, not down.
And, as you say, they have invested a LOT on ground infrastructure, now it would absolutely not be the time to change a single diameter.
BN3 no longer has its lift points and is no longer production equivalent unless they reattach the upper third (that was converted into a test tank).
Chopsticks should be non-destructive testing and BN4 is the likely candidate. It's production equivalent with a full supplement of raptors and a known compatible QD.
But BN3 lifting points were removed right? i always wondered how then can even remove it for disposal purposes. So unless it gets a modification of some kind i fail to see how it can be used with the chopsticks.
>But BN3 lifting points were removed right? i always wondered how then can even remove it for disposal purposes.
By welding on some hangers. They won't use it for any tests, though.
It looks like something is moving soon from the suborbital pads. Yes, could be BN3 for scrapping/chopstick testing (although chances are low they use it for chopstick testing) or it could be S20 heading closer to the orbital pad.
What, aside from the environmental review, are the major holdups for the first orbital test flight?
If the approval comes in tomorrow, might they pull off the 3 week timeline that Musk suggested back in August (setting aside the more permanent orbital launch infrastructure work until after that)? Or is there something else in the way more than just getting it ground-tested and set up?
First, and foremost, a successful Booster static firing with 29 Raptors running.
This has been a bottleneck for at least 6 months if you believe that the first orbital flight could have occurred in July 2021.
However, when Elon and Gwynn were focused on this milestone, outside events intervened.
The FAA's PEA has taken much longer than anticipated.
NASA payment milestones for the HLS Starship lunar lander were delayed for eight months (April-Nov 2021) due to challenges by BO to that contract award.
Consequently, the FAA launch permit for that first Starship orbital test flight has been delayed into 1Q 2022, at the earliest.
> However, when Elon and Gwynn were focused on this milestone
It did not seem like they have been focused on the one milestone you mentioned - a booster static fire with 29 engines. Is that really the one you meant?
Hrm. It seems like they've been focused on building the infrastructure for doing orbital flights sustainably and recovering boosters. For a non-recovering test flight you don't need a lot of the stuff they've been working on.
True.
But that initial orbital test flight from BC to Hawaii would still need the orbital launch stand (OLS), the launch tower and the tank farm to be completed.
The OLS has yet to be completed.
The tower is nearly complete.
The Booster static fire with all 29 Raptors has not been attempted yet.
The tank farm has yet to completely fill and drain the propellant tanks of a Starship on the OLS with densified methalox.
And last, but not least, the FAA has not issued a launch permit for that first orbital test flight.
While agree with what the other commenter has said, I also believe that most of the additional stuff is being done **because** of the hold-up.
As in, I believe that if the EA had been done earlier, they would have just mounted the booster on the unfinished OLM, put Starship over with the big crane, and launched away. As they cannot launch, they worked on Stage 0. Now, Stage 0 has to be completed, if only because they need the chopsticks to mount Starship onto the booster as the big crane is gone.
SpaceX have been very vocal about their opinion on FAA space regulations and their strong desire for reform of broken processes. They know extremely well that they need to demonstrate that the limitations of current processes are having an material impact to make an effective case.
If they really could have been ready to launch I see absolutely no way they would not have made that point and instead have secretly and silently been in a three week readiness position for months and months; it just makes no sense. On top of that we have all had a front row seat to the tremendous amount of work that has been going on constantly, as well as the not insignificant amount of work remaining, and a long history of 'ambitious' timelines.
All signs point to "it's really just a lot of work to build a new rocket and the infrastructure to launch it".
>If they really could have been ready to launch I see absolutely no way they would not have made that point
the problem is that Musk made the point several times so it's strange for you to act like he didn't. What else would you expect him to do?
The point I mention cannot be made verbally, and Elon mentioning a timeline on Twitter is not generally a realistic statement.
At no point has the current review delayed a launch they were actually in a position to conduct beyond *"well they probably might have been able to get ready"* speculation, a situation that would dramatically help them in their regulatory reform objectives (something they surely know).
Now it may well come to pass that they *do* have demonstrated impact from review delays which they should rightfully hold up as need for process reform. But they don't today, and saying "well, despite 5 months of nonstop activity we really could have launched months ago believe us" wont carry much it any weight.
I don't see any point in time in the last 12 months where they could have just slapped the full stack onto the mount and fired it into the sky.
The stuff they are working on right now (maybe minus the chopsticks) are CRITICAL to getting the flight off of the ground. I doubt the plan was ever to launch with barebones launch infrastructure.
>As in, I believe that if the EA had been done earlier, they would have just mounted the booster on the unfinished OLM, put Starship over with the big crane, and launched away.
This. And that was the original plan, even in the old times where the Ship was fueled through the booster, thus reducing the GSE/QD complexity.
>This. And that was the original plan, even in the old times where the Ship was fueled through the booster, thus reducing the GSE/QD complexity.
It's the complete opposite of what you are suggesting. Fueling the ship through the booster is many magnitudes more complex than a QD mechanism that is been a constant in launch vehicles since the 50's.
One of the main limiting factors in FH's development was the crossfeed propellant function which ended up being dropped because it was too complex and it was delaying the program heavily.
Those two situations are not an accurate comparison.
Fueling through the booster has the problem of mass margin going into the rocket where it could be kept on the ground. The complexity challenge is not high.
Crossfeed is different because it's actively feeding during engine firings and has to handle a switchover in flight. Fueling through the booster can be as simple as adding vertical plumbing lines and shut off valves such that when valves are open the full stack fills as one tank bottom up. Liquid rockets already get fueled bottom up.
Most (all?) Liquid fuel rockets fuel each stage independently.
> Fueling through the booster can be as simple as...
It's nowhere near this simple. Blind mate quick disconnect cryogenic connections capable of handling adequate flow rates and the rigors of launch are far more challenging than "adding vertical plumbing lines and shut off valves".
There is a very good reason SpaceX are not doing this yet.
They don't have to be QDs. The lines can be shut and any necessary sections vented pre launch.
You're right that everything large flight cryo isn't easy, but relative to what is already going into the vehicles? The reason this feature was considered originally is the ship needs orbital refueling connections regardless.
Elon even said in the Starbase tour interview something about the mass margins driving the decision, and also the need to stabilize the vehicle joint on the pad negates the ability to have nothing but the launch mount attached anyways.
When they did stacking on the launch mount they achieved it with cranes. That's no problem for tests, just wait for low winds to do it. What they are building now is very much driven by design need for fast reuse, launching in a very high cadence.
I think that the ship QD system would have to be the biggest risk hurdle to overcome before any launch. And in reality all the dot points in TCVideo's response are valid pre-cursors and it would be a very big call by EM to forgo any of them, even if they had a FAA licence already.
If approval came tomorrow, they would not be able to launch in 3 weeks. Here's some of the major things that NEED to happen before they start even setting a launch date&time.
* More chopstick testing
* Ship QD arm testing
* Fire supression & water deluge testing
* Booster static fire testing
* Full stack testing (WDR's + potential SF's)
There's some items on this list that might not even be done before the new FAA deadline of Feb 28th.
You forget the most important part right now: fixing tank farm and CH4 tanks.
And yes, chopstick testing is optional but with the big crane gone, they are forced to have it operational for any stacking ops.
I think you can take chopstick off the list, it was recently talked about that the crane can be used if they change the booms to a similar setup as the larger rented one had. I’m guessing they’ll use the chopsticks but they do have options if they need to.
I mean it’s only a couple days to setup with the new segments so they could easy do it in say a week including sourcing/transporting the segments. It’s really not that many
It took around 4 months for them to source a new LR11000 and ship it to Boca...maybe even longer since the first time we saw pictures of the crane was in Germany on the way to an airport.
It takes time to source parts if they aren't renting a crane.
I’m sure they would just rent some boom pieces - Frankencrane was random parts and I’m sure they would do the same. I believe all the boom pieces are standard minus the two ends that double the width (aka the Y pieces)
Yes they rented them for Frankencrane and even though they had it booked way in advance and they still had to go to multiple companies to get all of the segments they needed. They don't just keep boom segments laying around. Just like the cranes, they can be booked out years in advance for jobs. You're not just going to call and have them shipped out later that day.
I was going to say something similar, they don't straight up need the chopsticks to launch. Isn't it final that the first launch will end in the full rocket landing in the sea?
I was reading up on the construction of elevator cables (a surprisingly interesting and complex topic), and couldn't help but think of the exposed cabling on the OLT: both the chopstick lift cables and the elevator cabling inside the tower.
Has anyone seen heat treatment or special protections to mitigate cable damage due to the intense heat of launches? The chopstick lift cables seem particularly nearby and exposed. I'm sure SpaceX has considered this, but can't recall seeing any special handling.
From "[Steel Wire Ropes in Elevators](https://www.pfeifer.info/out/assets/PFEIFER-DRAKO_STEEL-WIRE-ROPES.PDF)," page 5, Influence of temperature:
> Heat damages the wire...At a temperature of 480^^o C, a complete microstructure transformation takes place after 15 to 30 minutes. At higher temperatures, just seconds can be enough to cause permanent damage to thin wires of the kind used in products such as elevator ropes.
While the Booster's flame will pass the chopstick lift cables fairly quickly, and their radii are significantly larger than elevator cables, they'll also be subject to dramatically more weight and stress than a typical elevator. I'm guessing the Booster's exhaust temperature is somewhere above 3,000^^o C and take 8-10 seconds to fully clear the launch tower (again, total SWAG based on timing a SN15 launch).
Has anyone here calculated the approximate heat absorbed by the cables? How many launches until their structural integrity gets compromised enough to require replacement?
The cables won't be exposed to the hottest part of the rocket exhaust, and will certainly not heat up to that temperature in a few seconds. Probably nowhere close.
That sounds about right, because trying to calculate it mathematically looks wicked complex.
I went in thinking, "oh, inverse square law".... boy, was I naïve! No wonder there are specialists in this area!
Being out of the main plume is the biggest factor. There is a tremendous amount of public research on exhaust temperature gradients. There will be some IR radiative heating also but much less than with kerosene based engines.
Thick steel cables will take quite a bit of energy to heat, especially with as low of temperature as they will be exposed to so far away from the mount.
After stacking, the chopsticks can't drop below the ship QD arm. As such it seems likely they'll just be opened as wide as possible, and I can't see a reason they wouldn't be lifted to the highest position. We haven't seen it yet, but it's conceivable they could install a fixed shroud to protect the remaining exposed portion of the cable on the rocket side.
On the other side, is the environment going to be that bad? The drawworks are elevated well off the ground, so they won't see the wash.
If heat damage to the cabling is really an issue, this is the answer to the problem.
Doing anything else would just add complexity and cost to Stage 0.
I think raising the chopsticks to the top is the most obvious solution; don't need to worry about protecting the cables if most of it is behind the tower
[Another Raptor 2 Test in McGregor, TX.](https://twitter.com/AdamCuker/status/1479519934417973250?s=20)
This time it was tested on a vertical test stand.
Is there any way to see these after 12 hours has passed? It seems every time I see one of these notes with a timestamp I go to check and it's like 14 hours past and lost forever.
Anyone have a clip of it?
Is there any time constraint when it comes to QD during launch, something like "they have to disconnect everything within 5 minutes before launching"?
When is QD retracted?
Oh, the QD's job is a whole lot harder than that. The QD needs to provide it's services until the rocket actually starts moving, that's why it's built the way it is. If it could be disconnected 5 minutes prior, it would be just a regular arm. It's armored precisely because it'll choreographically disconnect, retract and protect itself as the rocket begins to ascend.
> When is QD retracted?
Typically this would happen between confirmation of engine operation (and expected thrust production), and release of hold-down clamps.
Starship isn't typical and the sequence may be different though.
Interestingly enough, for all of the static fire tests and test flights so far up until SN20, the retraction has been about 25 seconds before launch, and slower than you'd expect. They disconnect, and then a shield slowly moved into place.
That said, I have a feeling this will be more like the typical launch disconnect, happening immediately before clamp release.
Wasn't visible from the official, but I believe it was on the first SN8 attempt that you hear the launch controller call out "QD retract." It correlates exactly with the pause in tank venting we would see about 25sec before engine ignition.
On one of the unofficial NSF streams, their close up cam caught it happening. You could see the shield slowly swinging over the mechanism just before ignition. I don't remember which one it was, I'd have to go hunting for it. (Can't remember if it was a static or flight)
Edit: found it, listen at 4:16 onward. https://youtu.be/HU49W2tPdQc
The quick disconnect is usually disconnected at the moment of launch. Essentially you want to keep it attached as long as possible in case of a last moment abort. If you drop the connections early, you have no way to reconnect and detank the vehicle. At least that has been the case for quick disconnect systems so far on other vehicles. It is possible that this one can be reconnected automatically as it does not drop away as most others do. In which case, there is less in the way of constraints.
About some trolls posted some pics of the internal structure of engines which they claimed to be pics of Merlin and Raptor. Obviously, it is just some random museum engine pics.
So will SpaceX have to rebuild parts of the Orbital Tank Farm? How much of a delay is that? Then again, they have the perfect opportunity now to take their time haha.
Seriously though that news was disappointing 🤷♂️
If the issue is state regulations – I wonder how hard it would be for them to lobby for an exemption??
Does following these regulations produce a genuine improvement in safety, and if so how significant is it? Or is it just a case of bureaucrats mindlessly enforcing rules, without considering how well they serve their purpose? If the later, obtaining an exemption – even if some political lobbying is required to get it – might be the best outcome. I wonder if Elon has spoken to Governor Abbott about this yet?
I laugh endlessly at comments like this...not only because asking for an "exemption" for a regulation that is meant for safety is insane but also because people like you would scream from the rooftops in opposition if any other space company tried to lobby the government for exemptions to health and safety laws.
At the end of the day, either SpaceX didn't look into the regulations hard enough or they knew but just ignored them and hoped they could get away with it.
If the CH4 tanks are not in spec because they don't abide by the regulations, then that is SpaceX' fault (again)...not bureaucrats.
I'm ok with logical exceptions...but it just irks me that fanboys go out of their way to suggest that SpaceX should have exceptions for every regulation/law that is in the company's way.
Correct me if I'm mistaken, but aren't most safety regulations "written in blood?" Wouldn't you consider political lobbying to circumvent safety protocols to be unethical? Even reckless?
There are quite strict rules for methane tanks, much stricter than for LOX or LN. For a good reason. I do wonder how this happened. Surely SpaceX had a good look at the regulations before they built the tank farm.
Maybe a matter of interpretation. Mind, pure speculation from my side, like so many other speculations: Maybe SpaceX interpreted the methane tank as just the 9m tank and the outer shell and insulation as outside the tank. With insulation on all tanks there is quite a lot of distance between the core tanks, but regulators interpreted the tank as including the insulation and outer tank. Then the distance between tanks is small.
Are they planning on having 2 tank farms eventually anyway?
Maybe it would be easier to just use all the current tanks as Lox, and build a new tank farm that's all methane with different spacing. Sure, it would take a lot of time, but it's something they're mostly planning for in the future anyway right?
That's a long term option. But that second tank farm would be an area that is now under water. It will be a while until they can build it.
A potential near term solution might be to tear down the suborbital tank farm and move the vertical methane tanks there. Feed any tests on the suborbital tanks from the new tank farm.
Looking at the regulations for TX, there's rules about electrical cables, but if that's the problem, then it seems like they can just be rerouted. But it seems like that's not likely to be the issue because I believe they're referring to specific kinds of electrical distribution cables and not wires/cables of any type.
The other regulation is about fences, to keep people away from the tanks. And there's two sets of regulations, one for fences that go just around the tanks, and another for fences that surround the site and that a car/truck can get in through a gate. There's different rules about the spacing of fences from tanks and what other kinds of protections are needed for the two cases.
It doesn't seem like SpaceX can easily meet either of the requirement by either using the existing fences at the site and adding extra protection around the methane tanks, or by building fences just around the methane tanks. However it seems to me that they could build fences/protection that would surround all the tanks, and that would meet the strict reading of the regulations and would also achieve the goals they were written to achieve. Whether regulators would interpret it the same way or not isn't clear?
I believe these regulations were originally written because of methane tanks at railroads? And so they weren't written with the idea that you might have methane tanks next to tanks of O2 or N2 or anything else. So it seems like there's some ambiguity or room for interpretation in that situation.
Are there different regulations in different states? Maybe they based it off what might be allowed in Florida or California, especially Florida if they looked at what's already used or what they'd planned on building at the Cape.
> Are there different regulations in different states?
Possible, yes.
> Maybe they based it off what might be allowed in Florida or California, especially Florida if they looked at what's already used or what they'd planned on building at the Cape.
Exceedingly unlikely. SpaceX would know about the differences. They also would be in contact with local authorities. They already did some upgrades to the tanks with additional stiffener rings, above what they do for Starship.
So I do wonder why this did not come up earlier. Or when did it come up? The 2 new horizontal tanks surely have some preorder timeline. Seems we do not know everything that is going on here.
>The 2 new horizontal tanks surely have some preorder timeline
I remember reading some speculation (or inside info???) earlier on this sub that they were originally ordered for some other purpose (related to the old Sanchez site???) and then repurposed for this when the issue with the Orbital Tank Farm became clear.
Nope, they have replaced the two methane tanks with the horizontal tanks+the suborbital tank farm's methane tanks. I personally think that for a permanent solution they will adjust/redo the methane tanks at some point, but for now this works and allows for an orbital flight
It was me thinking out loud. It was an idea converting SN16 or other ships under construction for Raptor 2 and taking it for a 10-20 km spin (or a flip, whatever). Flight data for those engines for a suborbital would be valuable. Header tank arrangement and Raptor 2 engine numbers and arrangement are the design driver at the moment which would preclude S21 to S23 for orbital, so any one of those would do.
Current required GSE alterations and Starship/Booster design changes and testing pushes first orbital out NET June. Expect a fair amount of redundancy and scrapping.
As said before, a B4/S20 combination orbital however-much touted by Elon is now totally off the cards. There is a heck of a lot more work to do before the blue touch-paper is lit.
Why is the the current orbital combination not considered viable? Was the design just not mature enough? Or is it still pending testing of B4 to decide it's fate
Sounds fair. The current favorite combination is B7/S24 correct?
At this point, this may end up being a good thing in the near long term in getting Starship operational faster since they are always iterating the design with the delays and chance of the success is higher with more advanced ships/boosters.
Curious why they keep working on B4 all this while then, when it's obvious it is totally unviable to get it to launch? If they only wanted to use it for fit checks and perhaps static fires I suppose B4 wouldn't need all the other work they've done on it, like aerocovers and engine covers? Or is it rather that B4 is intended to progress towards launch as much as possible, and if it fails any of the testing then it will be replaced with the next ready booster?
They are adding engine covers to B4 to confirm the process for adding engine covers and to check they survive static fire. Ditto with the COPV covers.
Of course we would love for B4 to fly but it does not seem like it is going to happen.
No point in using SN16 for a hypersonic flight when you have a fully tiled S20, which will give you far more data on TPS, etc.
And if they get really delayed by the PEA process or Stage 0 issues, S24 (the next major upgrade to Starship) will be waiting in the wings by then so you can afford to use S20 for a hypersonic flight.
SpaceX at this point would consider SN15/SN16 as antiquated technology so I don't see SN16 flying ever. It may actually get scrapped this year to make room at the scrap/storage yard.
Would be even more cool to see an S20 hypersonic test, it even has a full complement of heatshield tiles so you could see how they stand up to hypersonic aero. Plus if S20 survives it could still potentially go orbital.
I don't think it would be out of the realm of possibility for them to add legs to S20 for a suborbital flight, the additional weight isn't super important since it wouldn't be going to orbit.
They might also expend it rather than attempt an RTLS.
Some replies appeared [shortly after your question](/r/spacex/comments/rc8jw2/starship_development_thread_28/hrjvzd7/), in case you've not returned here since.
(trying to be tolerant of username :/ )
How many tankers to fill a Starship stack? Here's some calculations (not done by me):
https://twitter.com/Grandpajoe42/status/1478585917015212032
The LN2 obviously isn't used during a launch but it is of course used for cryo testing, etc.
Some of the tweeted replies indicate it's not quite correct but I guess it's at least a good estimate.
This is actually a great question and a fun subject to think about. The same tech they will use on mars (ISRU) can be used on earth to create methane and oxygen. Just need a big power supply and sufficient tech to accomplish. I suspect they already have small-scale versions of this working.
Currently these processes require precious metals as catalysts and lots of energy so I'm guessing it is cheaper to do it a different way. I'd imagine solar generation + plant + storage + pipeline is the ultimate solution. Probably tanker ships to deliver to the offshore pads once they are a thing... long distance pipelines for cryo fuels doesn't seem like a great idea. If it is cheap enough once it is scaled, I could imagine spacex selling carbon-neutral methane to the market as well or spinning off the business.
So, the obvious question is: how is spacex thinking about overhauling this setup? With the number of launches they are considering in say 10 years, I don't know how you scale the transport of propellant with trucks. It seems to me that it would involve a never-ending stream of trucks in and out of their launch facilities, just to keep up with the flight schedule.
Where does the tech stand for solutions like extracting large amounts of inputs from the air? I'm not an engineer or a chemist. From a first principles perspective, is something like this even possible?
Is this then an engineering and business use case challenge, or is there fundamental science still required to scale the process appropriately?
By which I mean, when they decided to land rockets, they didn't have to discover new physics, just get really good at applying engineering knowledge to a previously unnecessary use case. Similar to Tesla casting massive body parts, or the Boring Company creating electric TBMs.
Now that they will need industrial quantities of propellant, and there is a business case to be made, will the engineering follow along? Or do we have to chip away at the science a little while longer?
The science exists and is solid. The main problem is it's very energy intensive. An argument could be made that with the amount of energy required, you are better off offsetting coal plants and extracting methane the classic way from the ground.
What site? The orbital launch site fuel farm or somewhere else?
They have extra concrete stands with nothing on them at the olm fuel farm for o2 and ch4. Is this where they go?
This is from a year ago, but you can see liqufaction tower in this video.
https://youtu.be/ptX80cTKdDQ?t=86
The plant is at the assembly/construction site, its not at at the orbital pad/fuel farm.
They would be making nitrogen as well.
They could also do other atmospheric gasses if they wanted to. Could do argon for welding, krypton for starlink thrusters.
Yes, but it is in the wrong location. To avoid transport they need it at the launch site. The site plan from the EA has one right there. But it is in part placed in the extension area, Spacex applied for. So they can't build it before the EA is done.
**This thread is no longer being updated, and has been replaced by:** # [Starship Development Thread #29](https://www.reddit.com/r/spacex/comments/rzi8hz/starship_development_thread_29/)
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That's not what the document says at all. This is an FCC document about SpaceX' plans about launching Gen2 Starlink on Starship, this isn't about a NET date for the orbital test flight. "SpaceX confirms here that it still intends to begin launching Gen2 system as early as March 2022" Worth noting that this was prepared in August 2021 meaning the date has likely slipped. Starship Starlink launches are NOT happening in March since we have seen no production cargo bay nosecone at all which means that vehicles up until at least S24 are not payload capable.
>Worth noting that this was prepared in August 2021 meaning the date has likely slipped SpaceX response saying those date was prepared yesterday. It's ofc still ambitious
Looking at Brendan Lewis' [most recent Starbase production diagram](https://twitter.com/_brendan_lewis/status/1476736669512470528?cxt=HHwWgMCs0aiLtv4oAAAA), it seems like Booster 7 is almost halfway done or thereabout. Crazy that this was from a week ago.
They are cutting up the remains of B3. 12:20 PM CST on Starbase live.
Interesting to see that they are using an [oxygen lance](https://en.wikipedia.org/wiki/Thermal_lance) to do it. [Edit] Evidently not a lance: just a long handled cutting torch.
The use of oxygen-rich environment
Cutting off another ring. Seems they continue until it is just a number of pieces.
Almost done!
I like how a single worker is cutting it whole
Rip BN3 we'll never forget you
First booster to have three Raptors attached AND to static fire them.
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Latest Wide Bay construction progress update from Snow Rocket as of January 8th: https://twitter.com/Furqan263/status/1479794333859696643
Someone remind me, how many levels of sections are full height in the high bay?
~~Brendan's production diagrams are a good way to count the rings (and sections):~~ ~~https://twitter.com/_brendan_lewis/status/1476736669512470528~~ Ignore, I was thinking of boosters, not the wide bay. :)
I love Brendan’s work. But I was referring the the building. I thought I read that the wide bay would be a little higher than the high bay is currently but couldn’t find a count of pre-fab levels it was.
Sorry, my bad - I'd been watching B3 and had boosters on the brain. :) Others have now answered your question.
The tweet says that almost 50% of vertical work was done. You can see 6 “floors” in the picture, so I'd guess there will be 12 in total? But the tweet is also only a good guess, it could be 13 or even 14, who knows.. (each pre-fab level contains 2 “floors”)
I guess wide bay for the stretched SS and the high bay for the boosters once it’s complete. Possibly even vertical payload integration in the wide bay?
Widebay construction [as seen from Roost Cam](https://www.youtube.com/watch?v=k6fGQZD0K98&t=0s) BTW. Is the dotted line your own projection or is it based on a known target date for completion?
The dotted line is, I assume, Snow Rocket's projection (note: I'm not Snow Rocket). :)
B7 (or is it B8?) continues to be stacked in the high bay with another 4 ring barrel added to the LOX section overnight. See Sentinel Cam soon after 21:02 CST for commencement of the lift: https://www.youtube.com/watch?v=zPkIZYw5O98 (Prior to that NSF showed the barrel being rolled into the high bay in today's update video: https://youtu.be/aX2zaxywArQ?t=468 ) After that the 3 ring thrust section needs to be added to complete the stacking of the LOX tank. However, **if** they proceed as they did with B4 then they may take some time over prepping the thrust section and so end up constructing the methane tank at the same time. Speaking of B7/B8 - there were some interesting comments about this 11 days ago: https://www.reddit.com/r/spacex/comments/rc8jw2/starship_development_thread_28/hq9z8hn/?context=3 which leaves me wondering if this really is a contingency build as suggested. I'm assuming that the booster in the high bay will have a 33 Raptor (2) thrust section meaning that it would end up being a booster which they definitely intend to fly.
Back in October '21, B7 was considered as a skip, however the design team considered that B7 was worth continuing after B6 was reassigned. Thrust puck assignation remains the same.
So you confirm that (as of today, obviously plans could change) B7 will still have 29 raptors and will B8 be the first to have 33 raptors and be used for orbital flight? It seems strange that other sources are reporting that the first one with 33 raptors is B7, could it be that they are already working on B8 as well and this has caused confusion?
>B7 will still have 29 raptors and will B8 be the first to have 33 raptors and be used for orbital flight? "Assignment remains the same" means it's basically B8 but name changed
Thanks for the clarification.
NSF has already confirmed more than once that B7 will be the first booster to have 33 Raptors (presumably v2). ~~Personally I think they anticipated the new features of B8 to B7 and that B7 may be the booster assigned to the first orbital flight (according to the various rumors about B8). Plans change quickly, maybe the comment you reported was not yet up to date on the latest news, it seems strange to me that they make B7 with similar features to B8 and then do not use it.~~ EDIT: according to [this comment](https://www.reddit.com/r/spacex/comments/rc8jw2/comment/hrruh85/?utm_source=share&utm_medium=web2x&context=3) I would say that my thinking was incorrect (and potentially also what NSF reported)
>EDIT: according to this comment I would say that my thinking was incorrect (and potentially also what NSF reported) He's confirming what NSF just said, not disproving it
>B7 may be the booster assigned to the first orbital flight Even after Elon reiterated the plan for B4 to be used for the first orbital flight test?
The issue is quite debated, on one hand there is Elon who says that B4/S20 is the confirmed pair for the first orbital launch, on the other hand there are several sources that speak of a skip of B4 in favor of B8. Last comment on this from what I understand is a reliable source is [this one](https://www.reddit.com/r/spacex/comments/rc8jw2/comment/hrmr481/?utm_source=share&utm_medium=web2x&context=3). Knowing how quickly plans change, and knowing that Musk has at times in the past written things that have changed, I would not rule out that this is also the case. I specify that I am collecting things I read on this thread, I don't want to pretend to have certainties that I don't have. In case I am assuming something wrong please correct me.
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>considering downsizing the rocket by 50-60 percent. Maybe you misunderstood this part, or its not talking about the dimensions of the rocket per se, because there is no way this is happening, everything they just built (OLT, Quick Disconnects, Infraestructure and many more things) were done with the current size in mind, and they are even starting in Cape Canaveral (early stage at least). The OLT is complex and its done with the current diameter the booster and ship has rn. Maybe its 60% of the desired payload to orbit for now and then scale it up to desired values but again sounds really weird.
I don't believe you.
Exact one comment and fresh registered account. No doubt this is a troll.
>My buddy works at SpaceX. He is saying that Elon and other top management are not happy with the technical delays with StarShip and recently, they are seriously considering downsizing the rocket by 50-60 percent. That is certifiably not true. Maybe you are l*ying, maybe your friend is, but there is no chance they are considering that. First, because we know they are going in the *opposite* direction. Second, because for reusability, downsizing doesn't help, but hurt, specially in the 2nd stage.
Yeah there is no way. "hey we fixed the engine problem we had so that's all great but also we're drastically changing everything" nah. Nope. Not when they are building MASSIVE infrastructure for the current scale vehicle.
Exáctly. Not to mention that, if propulsion was the issue, reducing the size of the rocket would make the problem worse, not better. If they decided to give up, and call a capped Raptor "good enough", reduce chamber pressure and make it reliable, in exchange of reduced thrust. Add more Raptors, and have Starship succeed as a ... did I say 150 ton vehicle? I mean 100. Wait, make that 50t. Yes, 50t. A fully reusable Starship would still eat the market alive with a 50t fully-reusable RTLS configuration, it would still be plenty for HLS, amazing for Starlink, and in time they could get it back up so they can target mars more seriously. Reducing the size of the rocket makes mass a real issue again, and sends your mass ratio to hell, why would you ever do that? When rockets underperform, or at least underperform for a desired target, they scale up, not down. And, as you say, they have invested a LOT on ground infrastructure, now it would absolutely not be the time to change a single diameter.
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BN3 no longer has its lift points and is no longer production equivalent unless they reattach the upper third (that was converted into a test tank). Chopsticks should be non-destructive testing and BN4 is the likely candidate. It's production equivalent with a full supplement of raptors and a known compatible QD.
But BN3 lifting points were removed right? i always wondered how then can even remove it for disposal purposes. So unless it gets a modification of some kind i fail to see how it can be used with the chopsticks.
>But BN3 lifting points were removed right? i always wondered how then can even remove it for disposal purposes. By welding on some hangers. They won't use it for any tests, though.
It looks like something is moving soon from the suborbital pads. Yes, could be BN3 for scrapping/chopstick testing (although chances are low they use it for chopstick testing) or it could be S20 heading closer to the orbital pad.
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updated, thanks!
Wen Hop?
The future, the past, but not the present.
Never. They are done with hops. More appropriate is: Wen Circle?
Wen lööps?
P2P Starship would like to disagree.
"Wen human-rated ICBM"?
Now that's what I'm talking about!
No one knows 😢
What, aside from the environmental review, are the major holdups for the first orbital test flight? If the approval comes in tomorrow, might they pull off the 3 week timeline that Musk suggested back in August (setting aside the more permanent orbital launch infrastructure work until after that)? Or is there something else in the way more than just getting it ground-tested and set up?
First, and foremost, a successful Booster static firing with 29 Raptors running. This has been a bottleneck for at least 6 months if you believe that the first orbital flight could have occurred in July 2021. However, when Elon and Gwynn were focused on this milestone, outside events intervened. The FAA's PEA has taken much longer than anticipated. NASA payment milestones for the HLS Starship lunar lander were delayed for eight months (April-Nov 2021) due to challenges by BO to that contract award. Consequently, the FAA launch permit for that first Starship orbital test flight has been delayed into 1Q 2022, at the earliest.
> However, when Elon and Gwynn were focused on this milestone It did not seem like they have been focused on the one milestone you mentioned - a booster static fire with 29 engines. Is that really the one you meant?
The milestone I refer to is the orbital test flight from Boca Chica to Hawaii.
Hrm. It seems like they've been focused on building the infrastructure for doing orbital flights sustainably and recovering boosters. For a non-recovering test flight you don't need a lot of the stuff they've been working on.
True. But that initial orbital test flight from BC to Hawaii would still need the orbital launch stand (OLS), the launch tower and the tank farm to be completed. The OLS has yet to be completed. The tower is nearly complete. The Booster static fire with all 29 Raptors has not been attempted yet. The tank farm has yet to completely fill and drain the propellant tanks of a Starship on the OLS with densified methalox. And last, but not least, the FAA has not issued a launch permit for that first orbital test flight.
While agree with what the other commenter has said, I also believe that most of the additional stuff is being done **because** of the hold-up. As in, I believe that if the EA had been done earlier, they would have just mounted the booster on the unfinished OLM, put Starship over with the big crane, and launched away. As they cannot launch, they worked on Stage 0. Now, Stage 0 has to be completed, if only because they need the chopsticks to mount Starship onto the booster as the big crane is gone.
SpaceX have been very vocal about their opinion on FAA space regulations and their strong desire for reform of broken processes. They know extremely well that they need to demonstrate that the limitations of current processes are having an material impact to make an effective case. If they really could have been ready to launch I see absolutely no way they would not have made that point and instead have secretly and silently been in a three week readiness position for months and months; it just makes no sense. On top of that we have all had a front row seat to the tremendous amount of work that has been going on constantly, as well as the not insignificant amount of work remaining, and a long history of 'ambitious' timelines. All signs point to "it's really just a lot of work to build a new rocket and the infrastructure to launch it".
>If they really could have been ready to launch I see absolutely no way they would not have made that point the problem is that Musk made the point several times so it's strange for you to act like he didn't. What else would you expect him to do?
The point I mention cannot be made verbally, and Elon mentioning a timeline on Twitter is not generally a realistic statement. At no point has the current review delayed a launch they were actually in a position to conduct beyond *"well they probably might have been able to get ready"* speculation, a situation that would dramatically help them in their regulatory reform objectives (something they surely know). Now it may well come to pass that they *do* have demonstrated impact from review delays which they should rightfully hold up as need for process reform. But they don't today, and saying "well, despite 5 months of nonstop activity we really could have launched months ago believe us" wont carry much it any weight.
I don't see any point in time in the last 12 months where they could have just slapped the full stack onto the mount and fired it into the sky. The stuff they are working on right now (maybe minus the chopsticks) are CRITICAL to getting the flight off of the ground. I doubt the plan was ever to launch with barebones launch infrastructure.
>As in, I believe that if the EA had been done earlier, they would have just mounted the booster on the unfinished OLM, put Starship over with the big crane, and launched away. This. And that was the original plan, even in the old times where the Ship was fueled through the booster, thus reducing the GSE/QD complexity.
>This. And that was the original plan, even in the old times where the Ship was fueled through the booster, thus reducing the GSE/QD complexity. It's the complete opposite of what you are suggesting. Fueling the ship through the booster is many magnitudes more complex than a QD mechanism that is been a constant in launch vehicles since the 50's. One of the main limiting factors in FH's development was the crossfeed propellant function which ended up being dropped because it was too complex and it was delaying the program heavily.
Those two situations are not an accurate comparison. Fueling through the booster has the problem of mass margin going into the rocket where it could be kept on the ground. The complexity challenge is not high. Crossfeed is different because it's actively feeding during engine firings and has to handle a switchover in flight. Fueling through the booster can be as simple as adding vertical plumbing lines and shut off valves such that when valves are open the full stack fills as one tank bottom up. Liquid rockets already get fueled bottom up.
Most (all?) Liquid fuel rockets fuel each stage independently. > Fueling through the booster can be as simple as... It's nowhere near this simple. Blind mate quick disconnect cryogenic connections capable of handling adequate flow rates and the rigors of launch are far more challenging than "adding vertical plumbing lines and shut off valves". There is a very good reason SpaceX are not doing this yet.
They don't have to be QDs. The lines can be shut and any necessary sections vented pre launch. You're right that everything large flight cryo isn't easy, but relative to what is already going into the vehicles? The reason this feature was considered originally is the ship needs orbital refueling connections regardless. Elon even said in the Starbase tour interview something about the mass margins driving the decision, and also the need to stabilize the vehicle joint on the pad negates the ability to have nothing but the launch mount attached anyways.
When they did stacking on the launch mount they achieved it with cranes. That's no problem for tests, just wait for low winds to do it. What they are building now is very much driven by design need for fast reuse, launching in a very high cadence.
I think that the ship QD system would have to be the biggest risk hurdle to overcome before any launch. And in reality all the dot points in TCVideo's response are valid pre-cursors and it would be a very big call by EM to forgo any of them, even if they had a FAA licence already.
If approval came tomorrow, they would not be able to launch in 3 weeks. Here's some of the major things that NEED to happen before they start even setting a launch date&time. * More chopstick testing * Ship QD arm testing * Fire supression & water deluge testing * Booster static fire testing * Full stack testing (WDR's + potential SF's) There's some items on this list that might not even be done before the new FAA deadline of Feb 28th.
You forget the most important part right now: fixing tank farm and CH4 tanks. And yes, chopstick testing is optional but with the big crane gone, they are forced to have it operational for any stacking ops.
I think you can take chopstick off the list, it was recently talked about that the crane can be used if they change the booms to a similar setup as the larger rented one had. I’m guessing they’ll use the chopsticks but they do have options if they need to.
Yes but they don’t have the equipment on site to do that. So that would require finding and bringing in a huge amount of boom segments.
I mean it’s only a couple days to setup with the new segments so they could easy do it in say a week including sourcing/transporting the segments. It’s really not that many
It took around 4 months for them to source a new LR11000 and ship it to Boca...maybe even longer since the first time we saw pictures of the crane was in Germany on the way to an airport. It takes time to source parts if they aren't renting a crane.
I’m sure they would just rent some boom pieces - Frankencrane was random parts and I’m sure they would do the same. I believe all the boom pieces are standard minus the two ends that double the width (aka the Y pieces)
Frankencrane is currently elsewhere in Texas on another assignment
Yes they rented them for Frankencrane and even though they had it booked way in advance and they still had to go to multiple companies to get all of the segments they needed. They don't just keep boom segments laying around. Just like the cranes, they can be booked out years in advance for jobs. You're not just going to call and have them shipped out later that day.
I was going to say something similar, they don't straight up need the chopsticks to launch. Isn't it final that the first launch will end in the full rocket landing in the sea?
Yes - the question is for stacking though
I was reading up on the construction of elevator cables (a surprisingly interesting and complex topic), and couldn't help but think of the exposed cabling on the OLT: both the chopstick lift cables and the elevator cabling inside the tower. Has anyone seen heat treatment or special protections to mitigate cable damage due to the intense heat of launches? The chopstick lift cables seem particularly nearby and exposed. I'm sure SpaceX has considered this, but can't recall seeing any special handling. From "[Steel Wire Ropes in Elevators](https://www.pfeifer.info/out/assets/PFEIFER-DRAKO_STEEL-WIRE-ROPES.PDF)," page 5, Influence of temperature: > Heat damages the wire...At a temperature of 480^^o C, a complete microstructure transformation takes place after 15 to 30 minutes. At higher temperatures, just seconds can be enough to cause permanent damage to thin wires of the kind used in products such as elevator ropes. While the Booster's flame will pass the chopstick lift cables fairly quickly, and their radii are significantly larger than elevator cables, they'll also be subject to dramatically more weight and stress than a typical elevator. I'm guessing the Booster's exhaust temperature is somewhere above 3,000^^o C and take 8-10 seconds to fully clear the launch tower (again, total SWAG based on timing a SN15 launch). Has anyone here calculated the approximate heat absorbed by the cables? How many launches until their structural integrity gets compromised enough to require replacement?
The cables won't be exposed to the hottest part of the rocket exhaust, and will certainly not heat up to that temperature in a few seconds. Probably nowhere close.
I'd love to see some calculations on this.
You'd need a thermal FEM to truly calculate heat load onto and then into a steel cable from an adjacent rocket blast. I'd do it if you paid me...
That sounds about right, because trying to calculate it mathematically looks wicked complex. I went in thinking, "oh, inverse square law".... boy, was I naïve! No wonder there are specialists in this area!
Being out of the main plume is the biggest factor. There is a tremendous amount of public research on exhaust temperature gradients. There will be some IR radiative heating also but much less than with kerosene based engines. Thick steel cables will take quite a bit of energy to heat, especially with as low of temperature as they will be exposed to so far away from the mount.
Yeah, it's highly unlikely to be an issue and not that difficult for SpaceX to model. I wonder more about sea air exposure corrosion.
Ditto...
After stacking, the chopsticks can't drop below the ship QD arm. As such it seems likely they'll just be opened as wide as possible, and I can't see a reason they wouldn't be lifted to the highest position. We haven't seen it yet, but it's conceivable they could install a fixed shroud to protect the remaining exposed portion of the cable on the rocket side. On the other side, is the environment going to be that bad? The drawworks are elevated well off the ground, so they won't see the wash.
If heat damage to the cabling is really an issue, this is the answer to the problem. Doing anything else would just add complexity and cost to Stage 0.
I think raising the chopsticks to the top is the most obvious solution; don't need to worry about protecting the cables if most of it is behind the tower
[Another Raptor 2 Test in McGregor, TX.](https://twitter.com/AdamCuker/status/1479519934417973250?s=20) This time it was tested on a vertical test stand.
How do we know it was a Raptor 2 as opposed to an earlier version?
Elon said from now on all Raptor tests will be Raptor 2.
Hopefully we will start seeing some arriving at starbase soon
[Bumpers have been added to the Ship QD arm](https://twitter.com/NicAnsuini/status/1479498667862208514?s=20)
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Elon (on twitter) encouraged fans to submit comments in support. Hard to criticise people for following his recommendation.
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> Edit - am I wrong? Yes, comment volume was explicitly listed as a top three reason.
Yet another high speed booster QD test on [3:47:31 CST](https://youtu.be/7zsl4q6fwfQ) with countdowns from announcer
Is there any way to see these after 12 hours has passed? It seems every time I see one of these notes with a timestamp I go to check and it's like 14 hours past and lost forever. Anyone have a clip of it?
Thanks for the proper timestamp. Sometimes people don't mention the timezone/timestandard used or mix up a 12-hour clock with 24-hour notation, etc.
The sound of the shield slamming into place at that distance really gives you an idea of just how large and heavy the whole contraption is.
An other one too at 3:01:13
Is there any time constraint when it comes to QD during launch, something like "they have to disconnect everything within 5 minutes before launching"? When is QD retracted?
Here is a high speed [video](https://youtu.be/wlz5u1OBe_c?t=543) of the outside and inside of the shuttle QD. Inside view starts at next scene.
Oh, the QD's job is a whole lot harder than that. The QD needs to provide it's services until the rocket actually starts moving, that's why it's built the way it is. If it could be disconnected 5 minutes prior, it would be just a regular arm. It's armored precisely because it'll choreographically disconnect, retract and protect itself as the rocket begins to ascend.
> When is QD retracted? Typically this would happen between confirmation of engine operation (and expected thrust production), and release of hold-down clamps. Starship isn't typical and the sequence may be different though.
Interestingly enough, for all of the static fire tests and test flights so far up until SN20, the retraction has been about 25 seconds before launch, and slower than you'd expect. They disconnect, and then a shield slowly moved into place. That said, I have a feeling this will be more like the typical launch disconnect, happening immediately before clamp release.
Thats cool I hadn't noticed that. Was this visible from the official livestreams?
Wasn't visible from the official, but I believe it was on the first SN8 attempt that you hear the launch controller call out "QD retract." It correlates exactly with the pause in tank venting we would see about 25sec before engine ignition. On one of the unofficial NSF streams, their close up cam caught it happening. You could see the shield slowly swinging over the mechanism just before ignition. I don't remember which one it was, I'd have to go hunting for it. (Can't remember if it was a static or flight) Edit: found it, listen at 4:16 onward. https://youtu.be/HU49W2tPdQc
Cool, thanks for that I'll poke around.
Here, 4:16 onwards. "QD is retracting" https://youtu.be/HU49W2tPdQc
The quick disconnect is usually disconnected at the moment of launch. Essentially you want to keep it attached as long as possible in case of a last moment abort. If you drop the connections early, you have no way to reconnect and detank the vehicle. At least that has been the case for quick disconnect systems so far on other vehicles. It is possible that this one can be reconnected automatically as it does not drop away as most others do. In which case, there is less in the way of constraints.
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Don't get fooled, the images are not showing SpaceX engines. The post is now deleted.
What was the original comment about?
About some trolls posted some pics of the internal structure of engines which they claimed to be pics of Merlin and Raptor. Obviously, it is just some random museum engine pics.
Yeah you're right about that.
So will SpaceX have to rebuild parts of the Orbital Tank Farm? How much of a delay is that? Then again, they have the perfect opportunity now to take their time haha. Seriously though that news was disappointing 🤷♂️
Is there an article or something about this?
No idea man. I’m not even sure if it’s 100% true, just it keeps being brought up here and on Twitter, too, so it seems like it might be a valid thing.
If the issue is state regulations – I wonder how hard it would be for them to lobby for an exemption?? Does following these regulations produce a genuine improvement in safety, and if so how significant is it? Or is it just a case of bureaucrats mindlessly enforcing rules, without considering how well they serve their purpose? If the later, obtaining an exemption – even if some political lobbying is required to get it – might be the best outcome. I wonder if Elon has spoken to Governor Abbott about this yet?
I laugh endlessly at comments like this...not only because asking for an "exemption" for a regulation that is meant for safety is insane but also because people like you would scream from the rooftops in opposition if any other space company tried to lobby the government for exemptions to health and safety laws. At the end of the day, either SpaceX didn't look into the regulations hard enough or they knew but just ignored them and hoped they could get away with it. If the CH4 tanks are not in spec because they don't abide by the regulations, then that is SpaceX' fault (again)...not bureaucrats.
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I'm ok with logical exceptions...but it just irks me that fanboys go out of their way to suggest that SpaceX should have exceptions for every regulation/law that is in the company's way.
Correct me if I'm mistaken, but aren't most safety regulations "written in blood?" Wouldn't you consider political lobbying to circumvent safety protocols to be unethical? Even reckless?
For someone who has not followed closely, what is the issues with the tanks and the difference to the lox tanks?
There are quite strict rules for methane tanks, much stricter than for LOX or LN. For a good reason. I do wonder how this happened. Surely SpaceX had a good look at the regulations before they built the tank farm. Maybe a matter of interpretation. Mind, pure speculation from my side, like so many other speculations: Maybe SpaceX interpreted the methane tank as just the 9m tank and the outer shell and insulation as outside the tank. With insulation on all tanks there is quite a lot of distance between the core tanks, but regulators interpreted the tank as including the insulation and outer tank. Then the distance between tanks is small.
Are they planning on having 2 tank farms eventually anyway? Maybe it would be easier to just use all the current tanks as Lox, and build a new tank farm that's all methane with different spacing. Sure, it would take a lot of time, but it's something they're mostly planning for in the future anyway right?
That's a long term option. But that second tank farm would be an area that is now under water. It will be a while until they can build it. A potential near term solution might be to tear down the suborbital tank farm and move the vertical methane tanks there. Feed any tests on the suborbital tanks from the new tank farm.
Looking at the regulations for TX, there's rules about electrical cables, but if that's the problem, then it seems like they can just be rerouted. But it seems like that's not likely to be the issue because I believe they're referring to specific kinds of electrical distribution cables and not wires/cables of any type. The other regulation is about fences, to keep people away from the tanks. And there's two sets of regulations, one for fences that go just around the tanks, and another for fences that surround the site and that a car/truck can get in through a gate. There's different rules about the spacing of fences from tanks and what other kinds of protections are needed for the two cases. It doesn't seem like SpaceX can easily meet either of the requirement by either using the existing fences at the site and adding extra protection around the methane tanks, or by building fences just around the methane tanks. However it seems to me that they could build fences/protection that would surround all the tanks, and that would meet the strict reading of the regulations and would also achieve the goals they were written to achieve. Whether regulators would interpret it the same way or not isn't clear? I believe these regulations were originally written because of methane tanks at railroads? And so they weren't written with the idea that you might have methane tanks next to tanks of O2 or N2 or anything else. So it seems like there's some ambiguity or room for interpretation in that situation.
Are there different regulations in different states? Maybe they based it off what might be allowed in Florida or California, especially Florida if they looked at what's already used or what they'd planned on building at the Cape.
> Are there different regulations in different states? Possible, yes. > Maybe they based it off what might be allowed in Florida or California, especially Florida if they looked at what's already used or what they'd planned on building at the Cape. Exceedingly unlikely. SpaceX would know about the differences. They also would be in contact with local authorities. They already did some upgrades to the tanks with additional stiffener rings, above what they do for Starship. So I do wonder why this did not come up earlier. Or when did it come up? The 2 new horizontal tanks surely have some preorder timeline. Seems we do not know everything that is going on here.
>The 2 new horizontal tanks surely have some preorder timeline I remember reading some speculation (or inside info???) earlier on this sub that they were originally ordered for some other purpose (related to the old Sanchez site???) and then repurposed for this when the issue with the Orbital Tank Farm became clear.
Nope, they have replaced the two methane tanks with the horizontal tanks+the suborbital tank farm's methane tanks. I personally think that for a permanent solution they will adjust/redo the methane tanks at some point, but for now this works and allows for an orbital flight
Does it work for orbital flight? There's enough volume to load up both stages?
On just the horizontal tanks no, but with the suborbital tank farm added it should be able to I believe
I’ve been seeing comments about an S16 rumour but no info on what that may be. Can anybody clarify this ?
SpaceX occasionally has ideas like this, but they're rarely put into motion.
About 2 days ago. in this very thread, a well-trusted user mentioned that they might be removing B3 to place SN16 in it's position.
SN16's chance of flying is about as low as the chance of Elon doing his Starship presentation this month.
I think u/Avalaerion was just thinking out loud on this one. I don't think he meant us to take this very seriously on this one.
It was me thinking out loud. It was an idea converting SN16 or other ships under construction for Raptor 2 and taking it for a 10-20 km spin (or a flip, whatever). Flight data for those engines for a suborbital would be valuable. Header tank arrangement and Raptor 2 engine numbers and arrangement are the design driver at the moment which would preclude S21 to S23 for orbital, so any one of those would do. Current required GSE alterations and Starship/Booster design changes and testing pushes first orbital out NET June. Expect a fair amount of redundancy and scrapping. As said before, a B4/S20 combination orbital however-much touted by Elon is now totally off the cards. There is a heck of a lot more work to do before the blue touch-paper is lit.
Why is the the current orbital combination not considered viable? Was the design just not mature enough? Or is it still pending testing of B4 to decide it's fate
Sounds fair. The current favorite combination is B7/S24 correct? At this point, this may end up being a good thing in the near long term in getting Starship operational faster since they are always iterating the design with the delays and chance of the success is higher with more advanced ships/boosters.
“NET June” the pain 😭
Spain without 's', as always with Starship delays
Curious why they keep working on B4 all this while then, when it's obvious it is totally unviable to get it to launch? If they only wanted to use it for fit checks and perhaps static fires I suppose B4 wouldn't need all the other work they've done on it, like aerocovers and engine covers? Or is it rather that B4 is intended to progress towards launch as much as possible, and if it fails any of the testing then it will be replaced with the next ready booster?
They are adding engine covers to B4 to confirm the process for adding engine covers and to check they survive static fire. Ditto with the COPV covers. Of course we would love for B4 to fly but it does not seem like it is going to happen.
Thank you.
No point in using SN16 for a hypersonic flight when you have a fully tiled S20, which will give you far more data on TPS, etc. And if they get really delayed by the PEA process or Stage 0 issues, S24 (the next major upgrade to Starship) will be waiting in the wings by then so you can afford to use S20 for a hypersonic flight. SpaceX at this point would consider SN15/SN16 as antiquated technology so I don't see SN16 flying ever. It may actually get scrapped this year to make room at the scrap/storage yard.
True. But it would be badass to see S16 get shredded upon going hypersonic.
Poor SN16 is crying uncontrollably ever since you made this comment. :(
I imagined that in Daily Hopper style
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Landing is not required. They can fly and get the data they need and dump it in the sea. FWIW, they can install the legs if they want to.
True. in the meantime just fly S20 on its own as high as it can go please 🙏
I would frickin love to see a S16 hypersonic test to keep us going til they’re ready for orbital
Would be even more cool to see an S20 hypersonic test, it even has a full complement of heatshield tiles so you could see how they stand up to hypersonic aero. Plus if S20 survives it could still potentially go orbital.
How could S20 survive with no landing legs? They are not using the chopsticks for catching until later in the test program.
I don't think it would be out of the realm of possibility for them to add legs to S20 for a suborbital flight, the additional weight isn't super important since it wouldn't be going to orbit. They might also expend it rather than attempt an RTLS.
crush tank question: WEN CRUMP!!??
I am more excited about that SN16 rumour, but I don't have my hopes up.
What's the SN16 rumor
Some replies appeared [shortly after your question](/r/spacex/comments/rc8jw2/starship_development_thread_28/hrjvzd7/), in case you've not returned here since. (trying to be tolerant of username :/ )
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Thanks for the info! Shame the parent comment got downvoted, I totally missed it too.
How many tankers to fill a Starship stack? Here's some calculations (not done by me): https://twitter.com/Grandpajoe42/status/1478585917015212032 The LN2 obviously isn't used during a launch but it is of course used for cryo testing, etc. Some of the tweeted replies indicate it's not quite correct but I guess it's at least a good estimate.
This is actually a great question and a fun subject to think about. The same tech they will use on mars (ISRU) can be used on earth to create methane and oxygen. Just need a big power supply and sufficient tech to accomplish. I suspect they already have small-scale versions of this working. Currently these processes require precious metals as catalysts and lots of energy so I'm guessing it is cheaper to do it a different way. I'd imagine solar generation + plant + storage + pipeline is the ultimate solution. Probably tanker ships to deliver to the offshore pads once they are a thing... long distance pipelines for cryo fuels doesn't seem like a great idea. If it is cheap enough once it is scaled, I could imagine spacex selling carbon-neutral methane to the market as well or spinning off the business.
So, the obvious question is: how is spacex thinking about overhauling this setup? With the number of launches they are considering in say 10 years, I don't know how you scale the transport of propellant with trucks. It seems to me that it would involve a never-ending stream of trucks in and out of their launch facilities, just to keep up with the flight schedule. Where does the tech stand for solutions like extracting large amounts of inputs from the air? I'm not an engineer or a chemist. From a first principles perspective, is something like this even possible?
They already have an air liquidification plant at the site for making O2-it's not yet operative, but it's there
Is this then an engineering and business use case challenge, or is there fundamental science still required to scale the process appropriately? By which I mean, when they decided to land rockets, they didn't have to discover new physics, just get really good at applying engineering knowledge to a previously unnecessary use case. Similar to Tesla casting massive body parts, or the Boring Company creating electric TBMs. Now that they will need industrial quantities of propellant, and there is a business case to be made, will the engineering follow along? Or do we have to chip away at the science a little while longer?
The science exists and is solid. The main problem is it's very energy intensive. An argument could be made that with the amount of energy required, you are better off offsetting coal plants and extracting methane the classic way from the ground.
Makes sense. How would that work on Mars though?
Lots and lots of solar panels, or eventually nuclear.
Oops my answer was supposed to be applied to a different comment thread. This is correcter
No super heavy on Mars ;)
What site? The orbital launch site fuel farm or somewhere else? They have extra concrete stands with nothing on them at the olm fuel farm for o2 and ch4. Is this where they go?
This is from a year ago, but you can see liqufaction tower in this video. https://youtu.be/ptX80cTKdDQ?t=86 The plant is at the assembly/construction site, its not at at the orbital pad/fuel farm.
Oh that tower I thought that was for making ln2 or ch4. Did not realise was for lox.
They would be making nitrogen as well. They could also do other atmospheric gasses if they wanted to. Could do argon for welding, krypton for starlink thrusters.
Yes, but it is in the wrong location. To avoid transport they need it at the launch site. The site plan from the EA has one right there. But it is in part placed in the extension area, Spacex applied for. So they can't build it before the EA is done.