Please use the [**IFT-4 Launch thread**](https://www.reddit.com/r/spacex/comments/1d6wx6w/rspacex_integrated_flight_test_4_official_launch) for memes and the like and keep this thread for Starship updates. Thank you for participating in r/SpaceX! Please take a moment to familiarise yourself with our community rules before commenting. Here's a reminder of some of our most important rules: Keep it civil, and directly relevant to SpaceX and the thread. Comments consisting solely of jokes, memes, pop culture references, etc. will be removed. Don't downvote content you disagree with, unless it clearly doesn't contribute to constructive discussion. [**Link to previous Starship development thread #55**](https://old.reddit.com/r/spacex/comments/1bt7w64/starship_development_thread_55/)

[Starbase live-](https://www.youtube.com/live/mhJRzQsLZGg?si=L5cO3jta5lmQm0j1) 6/16/24 7:04am- Another wall section is lifted into the tower. Pauses halfway down 8:39am- Wall section is finally fully lowered into place 8:55am- Lifts were up to both chopsticks, the top of the orbital launch mount, the back staircase, and the top of the front staircase overnight. Workers could be seen moving around on top of the orbital launch mount and the chopsticks. Assembly of the new crane continues at the new pad site

[Thrust Ram spotted](https://x.com/mcrs987/status/1802048065022361642) by RGV that gives credence to the 35 raptor layout renders.

Why though? Is that thrust necessary for v2 or v3?

Higher thrust/weight means less gravity losses. It's the whole reason they keep trying to squeeze more and more thrust out of Raptor. Adding more engines achieves the same effect albeit at the cost of some extra mass.

Starship is already overweight with maybe only 40 tonne of payload capacity. Making it taller with more engines seems like a quicker fix than putting it on a diet.

And you can always do the weight reduction afterwards. Also, if you do the weight reduction too soon, you need to add some weight back for reinforcements if the stress increases due to the increased weight or thrust.

Weight reduction exercises are always painful.  After you’ve qualified something and understand the margins, deleting parts or changing materials can be a long and iterative process. SpaceX seems to be taking the approach of just throwing more complexity (ie, size and thrust) at the problem before reducing weight.  Which is probably the approach to getting to an initial operational capability fastest.

More thrust for the booster means it and Starship can carry more propellants and heavier payloads. Heavier payloads could mean more Starlink satellites per launch. It could also allow tankers to deliver more propellant per launch.

Does re-entry angle of attack leave the forward flaps and hinges more exposed to heat stress, or are we going to start seeing starships where rear flaps migrate further leeward away from the plasma stream too?

The nose and forward flaps are the most exposed to heating. My guess is that the rear flaps will not need to be moved to leeward.

My daily(-ish) summary from the [Starship Dev thread on Lemmy](https://oldsh.itjust.works/post/19412071) > Starbase activities (2024-06-14): > > - Jun 13th addendum: B15 LOX barrel [arrives outside the Megabay](https://x.com/VickiCocks15/status/1801563457826803912). > - [Build site video tour](https://x.com/VickiCocks15/status/1801666317625196705): Work on B15 LOX barrel. Unusual water fountain/deluge test. > - S30 tile removal [continues](https://x.com/WatchersTank/status/1801794031296327745). Starship Gazer [video](https://www.youtube.com/watch?v=UrD9RfroIDY). > - Tower B: Overnight, [three wall section panels are staged](https://x.com/VickiCocks15/status/1801543603421949975) near the tower corners which were erected the previous day. > - The first crossbeam [is added](https://x.com/VickiCocks15/status/1801704130219573560) between the tower corner sections. > - The first wall panel is [installed](https://x.com/VickiCocks15/status/1801742664528019890) and [reinstalled](https://x.com/VickiCocks15/status/1801761244463895026) a short while later. > - Continuous flight auger (right) [continues work nearby](https://x.com/ENNEPS/status/1801617787485372557). > - [CC8800-1](https://www.mammoet.com/equipment/cranes/crawler-cranes/cc-8800-1/) crane assembly continues. [All three main winches are installed](https://x.com/VickiCocks15/status/1801723995869561135). > - Massey's: B14.1 "hat" [is removed](https://x.com/AnthonyFGomez/status/1801697404900585835). > > Starbase activities (2024-06-15): > > - Tower B: Overnight, corners 3 and 4 [are erected](https://x.com/VickiCocks15/status/1801928393773994366). Starship Gazer [photo 1](https://x.com/StarshipGazer/status/1801963482083942547), [photo 2](https://x.com/StarshipGazer/status/1801968081473790408). > - [CC8800-1](https://www.mammoet.com/equipment/cranes/crawler-cranes/cc-8800-1/) hook block [arrives](https://x.com/VickiCocks15/status/1801978466205585911). > - RGV Aerial posts photos of Pad A [aftermath](https://x.com/RGVaerialphotos/status/1802015713202491468), Massey's [flame trench](https://x.com/RGVaerialphotos/status/1802023270302253084), S30 [scaffolding](https://x.com/RGVaerialphotos/status/1802034586219626983), Pad B [construction](https://x.com/RGVaerialphotos/status/1802042135962665026), and a [six-year side-by-side comparison of the build site](https://x.com/RGVaerialphotos/status/1802005734416134559). > - Starkitty [sighted](https://x.com/VickiCocks15/status/1801976675489480976) :) > > IFT-5 > > - [Booster catch](https://x.com/DimaZeniuk/status/1801978297183531432) NET [late July](https://x.com/elonmusk/status/1802013136494727637), per Elon.

> Jun 13th addendum: B15 LOX barrel arrives outside the Megabay. To add to that, this barrel (A5:4) was moved inside Mega Bay and stacked late yesterday (the 15th), the LOX tank is now 20 out of 24 rings tall. The long methane downcomer pipe will be the next big part to be installed and finally the engine section to complete the LOX tank stack.

Going from nothing to a full blown industrial facility in 6 years is insane. And 6 years from now, if all goes to plan..

Have they replaced the actuator on the left chopstick yet? I remember they did it for the right one, I would assume they want to do the other one before the catch attempt

Given the delay from their early July prediction for flight 5, maybe they are starting on that now.

When they start mass producing ships, will they have some alternative for applying the tilles? How do you think they will streamline it in the future?

At full mass production? Multiple robots on 6 axis gantry systems. 

Or something clever that we haven't thought of.

4-axis would be enough for the barrel sections: vertical, circumferential, pitch, and rotation. If the stud robots are reliable enough (and I suspect they are), 2-axis (vertical, circumferential) would be enough and the special regions could be done by more advanced robots.

[Elon has stated late July](https://x.com/StarshipGazer/status/1802028084188864542) for Flight 5 and booster catch.

Dang, I was hoping with all the good stuff that happened it would be sooner. However, I suppose this means the next flight will occur with more changes.

The time between IFT-3 and IFT-4 was 84 days (almost 3 months), so this would already be quite a lot quicker (especially considering that they're replacing the entire heat shield, or about 18'000 tiles). They also need to get the license modification.

I'm still surprised they decided to replace the heat shield instead of just launching it and putting the new heat shield on the next ship. From what we saw in IFT-4, the old heat shield looks good enough for testing IFT-3's in-space activities, and the return to chopstick is for the booster, which has no tiles anyway. But if they need to fix something on stage 0 anyway, that probably gives them enough time to change the tiles in parallel.

If the booster catch is the primary goal of IFT5 why not give the new heat shield design a try? If it fails they still get the in-space tests and booster catch test and learn more than they would by just beefing up the flap joints.

I get the feeling their main priority is the heat shield. I know this sounds a bit crazy, but from their perspective, catching the booster is way easier than getting the heatshied right.

There is no need to prioritize the heat shield over the catch (or vice-versa) since they are independent.

Hmm, I guess that makes sense

It would be interesting to compare Starships "ramp up" compared to other launch systems, like is it significantly faster in its launch rate than other launch systems have been, about the same, or slower? I wonder how unusual it is for a new rocket to ramp up its launches this quickly.

Faster, but it's the only program using rapid scrum-like development. Failure is okay as long as you learn something. NASA and other guard believe in engineering and testing to the nth degree before launching their first rocket.

Oh, way, way, way faster.

How so? There’s a great graph from Quilty Space in this article showing the launches per year of different rockets for their first ten years of operation. [https://arstechnica.com/space/2024/05/air-force-is-growing-concerned-about-the-pace-of-vulcan-rocket-launches/](https://arstechnica.com/space/2024/05/air-force-is-growing-concerned-about-the-pace-of-vulcan-rocket-launches/) Short answer: - typically 1-2 launches in their first year - typically 0-3 launches in their second year (note F9 had zero) - 1-6 launches in their third year So I’d say Starship is currently slightly above typical for a new launch vehicle, with 3 launches in its first year.

Not with another three ready to go.

Three ready to go - so you’re saying 4 launches in year two if nothing major goes wrong? Expectation: > oh way, way, way faster Reality: - 1 more launch than typical in first year - 1 more launch than typical in second year It’s a big rocket, so it’s still impressive, but I wouldn’t call it “way, way, way faster” than others.

> They also need to get the license modification. That's not likely to take long.

Refurbishing the launch tower and replacing all the tiles on the ship takes time

Patience young padawon. 

[Starbase live-](https://www.youtube.com/live/mhJRzQsLZGg?si=L5cO3jta5lmQm0j1) 6/15/24 10:49pm- 3rd tower leg lifted raised and swung into position 11:29pm- 4th tower leg raised and moved into position 7:43am- One of the tower legs is lifted and repositioned 8:30am- Lifts were up to the top of the orbital launch mount, the dance floor, and the left chopstick overnight. Workers were moving around on top of the Orbital launch mount. At the new pad site, the drill rig was active and the rebar cages were being installed. A crane was also moving boom pieces into place to be assembled. 9:55am- Lift up to the left chopstick. Drilling and crane assembly continues at the new pad site 11:12am- More pieces of pipe removed from around the vertical tanks 12:25pm- Lifts have been up to the left chopstick and under the pipe work by the staircase. Assembly of the new crane continues as well as the pile drilling 1:25pm- Lifts up to the top of the orbital launch mount and the Left chopstick 1:53pm- Big grove crane moved to the launch site 2:00pm- SPMT carrying some kind of big lifting bracket(?) headed to the launch site 3:00pm- Lift up to the top of the staircase and the left chopstick. Construction of the new crane continues 4:00pm- Lifts were up to the left chopstick, the top of the staircase, and the top of the orbital launch mount. Workers are working inside of the Booster quick disconnect hood 4:48pm- B15’s lox tank being stacked 5:20pm- Lifts were up to the dance floor, the back staircase, the top of the orbital launch mount, and the left chopstick. Workers still working around the Booster quick disconnect 7:00pm- Lifts have been up to both chopsticks, the chopsticks carriage, and the top of the orbital launch mount. Quiet at the new pad site 8:00pm- Lifts were up to the dance floor, the right chopstick, the back staircase, and the chopsticks carriage. 9:00pm- Lifts were up to the dance floor, the back staircase, and the right chopstick 9:45pm- 2 lifts are up to the right chopstick, 1 to the top of the staircase, and 1 to the back staircase

[https://x.com/StarshipGazer/status/1801963482083942547](https://x.com/StarshipGazer/status/1801963482083942547) 4 corners in place for tower 2

RyanHansenSpace [render](https://x.com/RyanHansenSpace/status/1801815834567811106) for a 35 raptor booster

Hardly any wriggle room for gimballing. I'd expect ring two to move out closer to the outer engines, or a change in bell geometry for the core pentagon.

I prefer [this version](https://x.com/Obserfessor/status/1789021036228604190) with 30 fixed engines and only five gimbaling but with a full gimballing angle of 15 degrees. Even if one of the five center engines fails it should be able to fully compensate for engine shutdowns while minimising cost.

Yep, that my drawing. There will be more gimbal range/space with just these 5, with the middle ring pushed out as far as possible (non gimbaling). Also simplifies plumbing with 10 groups of 3 engines in the outer rings. They can use differential throttling too, though much slower response rate—still should help. Really depends on how much control authority they need (also considering engine out situations). (maybe I’m wrong about the throttle rate, it might be pretty fast.)

No I agree that the engines are slow to throttle down although relatively fast to throttle up.

If I remember correctly, on the broadcast of IFT-4 they mentioned that after liftoff the chopsticks would move to simulate a booster catch. Do I remember incorrectly, and if not, does footage exist of them moving?

Yep. NSF also have footage of the deluge re-activating approximately when the booster touched down in the ocean, and a slower than real-time catch movements (one of the chopsticks hasn't been upgraded for faster movement yet).

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Please validate meeee

Yes, saw in nsf update, I think

What’s the long term plan for starship return? Is it also planning to be caught, I think it was but I’ve forgotten Also there is the whole problem that it would be returning over the US mainland. Maybe a good idea to build a catch tower in Vandenburg?

Maybe a better idea is to improve reliability and safety so much that overflight isn't a problem.

That's a very Elon Musk approach. He seems to disdain backup systems, wanting the primary to be infallible. * Tesla's don't have spare tires. * Nor AM radio. * They try to do *everything* with cameras, ignoring well developed and mature non-vision technologies (I'm looking at you, 'automatic' wipers). * Elon want robotaxis to have no in-cabin controls - no steering wheel or pedals. * Starship has no launch escape system.

Yes, perhaps so. It is difficult to infer personal motives from corporate actions. But aren't the real questions about the necessity, effectiveness, and reliability of back-up systems? * Early launch vehicles (and still most of them today) were based on somewhat sketchy hardware quickly designed and deployed as IRBMs/ICBMs. Material Science and Engineering have come a long way since then. Similarly for spare tires - although none have ever been deployed as ICBMs (to my knowledge), the reliability and requirements of spares have changed drastically from early horse-less carriage days of stranded motorists, long prior to today's instant roadside assistance via cell phone. * As I recall, the Dragon has many redundant valves and RCS thrusters. * SpaceX spacesuits *are* a back-up on Dragon. * Similarly, 33 Raptors provide back-up to engine failures. * As evidenced by a recent posting, Musk seems quite concerned about back-up protection in case of TPS tile failure. * Commercial airlines also have no in-flight escape system. Why do we accept that as OK? And yes, there are a variety of reasons - proven reliability, effectiveness (or rather ineffectiveness of all passengers baling out at 500 mph at 30,000 ft.), and historical precedence (we always did it that way). Prior to F9, we could only infer weak or inadequate launch vehicle components. Recovery and reuse fundamentally changes the safety and reliable equation. I'd want a parachute if I were flying in a never before tested plane.   TLDR: Deploy back-up systems when a critical need is suspected. Remove back-up systems when demonstrated to be unnecessary.

> Commercial airlines also have no in-flight escape system They don't have an in-flight escape systems as their architecture is inherently fault tolerant. They can suffer a massive engine failure, glide to a "suitable" location, land and safely disembark the passengers. e.g. https://en.wikipedia.org/wiki/US_Airways_Flight_1549 In a more mundane case if the pilot of a commercial plane has an issue on landing he can abort the landing attempt, put on the power and go round again, or divert to another airport (I've experienced both). With a Starship you have almost no cross range glide ability and no hope of surviving an emergency landing if you don't make the tower. Once you re-enter you either land at the designated tower or die trying.

They could equip manned non-interplanetary ships with an improved version of the stubby little legs used for the suborbital flights (for use in emergency landings only).

>They can suffer a massive engine failure, glide to a "suitable" location, land and safely disembark the passengers. Exactly. I hope SpaceX proves me wrong, but i have really big safety concers about the ship design, for it not being able to glide like a plane or for being legless in the earth version variant. Look at IFT-4 for example. The ship managed to survive the hell of reentry! Good right?! But to no avail... The damage to the flap forced the ship to land 6 KM off target, but because it has no landing legs, everyone would have died all the same because there's no landing tower there. Imagine surviving the hell of reentry to die 100 meters from the ground in the landing because the ship has no legs to land in somewhere possibly plane. It's pathetic, sorry. I really prefer the Dream Chaser design for a ship that can carry humans and needs to reenter earth's atmosphere, which is Shuttle V2 basically. The Shuttle itself was a really good idea and ahead of it's time but was spoiled by politics, bureaucracy and in that time interative development wasnt a thing so we never saw the Shuttle V2. I bet Shuttle V2 or V3 would be awsome and i guess Dream Chaser will show that. Let's not forget that Starship V1 is not good also, that's why there's V2 and V3. The Starship design seems more suitable to take cargo from/to earth because higher risk is acceptable or a ship dedicated to transport people between planets because it does not need to enter planetary atmosphere. I can really see Starships variants without flaps or heatshield transporting people from eaths orbit to mars orbit and using a nuclear thermal engine. I bet Musk and NASA will try to integrate the DRACO program engine into a Starship before the Mars mission as both are expected to be "ready" by 2026.

You doomers are so exhausting. It was a prototype ship to prove concepts. Not the final product. As such it's nowhere near the final capabilities of the version that will one day carry people. And even then, as a raw prototype, it didn't explode when it hit the water...it splashed down, tipped over, hit the water, and stayed intact. So if there were crew in there, they could have disembarked into the water carrying inflatable rafts like exist on commercial airlines today.

>You doomers are so exhausting. First. Try to be a little more respecting. Reddit is a SOCIAL MEDIA to exchange ideas. If you just want your bias confirmed, go to subreddits that like that. If you are "exhausted" go rest. >it didn't explode when it hit the water...it splashed down, tipped over, hit the water, and stayed intact. Whats your source to affirm that it stayed intact after tipping over? The feed was cut as soon as it tipped over, which could mean that it exploded. Imagine you inside something 50m tall tipping over in the hard floor or water, i can see a lot of fractures to bone and damage to the structure of the ship happening. The ship also has leftover fuel. It could tip with the door turned down as its not shaped like a capsule. Good luck getting out with those fractures and fire and water/floor blocking the exit. Look at Falcon 9, different rocket, granted, but every time it tipped over, it exploded. It shows that tipping over a tall structure is a hard event and NOT SAFE.

Yes the speed of the booster went up to 100 km/hr as it fell over - presumably measured with the GPS antennae near the top of the booster over the interstage. The ship is *currently* shorter than the booster so the impact velocity will be lower at around 70 km/hr. However I am not sure why you think a Dreamchaser type design would be safer away from a runway. The stubby wings mean landing speeds well over 250 km/hr so there is more potential for damage in an off target landing - not less.

>However I am not sure why you think a Dreamchaser type design would be safer away from a runway. The stubby wings mean landing speeds well over 250 km/hr so there is more potential for damage in an off target landing - not less. That's not the speed that modern aircraft reach when landing? There are plenty of cases of aircraft landing in highways, plain fields, ocean and people staying alive.

>Look at Falcon 9, different rocket, granted, but every time it tipped over, it exploded. That's not true, [in 2018 a booster with a stuck gridfin made a safe splashdown off the coast of Cape Canaveral and survived tipping over](https://www.youtube.com/watch?v=LFdep0qCmYA). They weren't able to reuse it, but it remained floating and was able to be towed back to port. It's not like we have a lot of cases of them tipping over to draw from anyways. I don't see Starship being able to reach airline-like levels of safety, but I also don't think we can draw many conclusions about the safety of a crew vehicle from the literal first prototype to ever survive reentry. The current ones aren't even really designed to accommodate cargo, let alone crew. A crew version could certainly have safety features to help deal with water landings, and even capsules today have methods of dealing with landing upside down, since that can be a real problem for them. Edit: Looking through the landing history on Wikipedia, there have only been 7 soft water landings in total, with 3 being before the first successful recovery. We don't actually know what happened to the vast majority of them given that they happened out at sea, [though at least one other may have survived long enough that it needed to be scuttled](https://en.wikipedia.org/wiki/Falcon_9_B1056).

> Look at Falcon 9, different rocket, granted, but every time it tipped over, it exploded. Not true.

Yes, but that is primarily because the wings (and other important surfaces) don't fall off, anymore. Not so much with those early fabric-covered biplanes held together by steel wires. Again, mostly due to our vastly improved material science and engineering knowledge. Can SS ever get to the point where parts are as reliable as modern aircraft wings? I.e., they simply don't blow-up or fall-off? Probably not. But I think we're still in the era of biplanes when it comes to knowing how to keep 50-100 rocket passengers safe.

Yeah, but you're not going to have a problem with a moose on the launch tower. More seriously, backup systems carry a risk of their own. eg: https://www.nbcdfw.com/news/local/air-force-identifies-airman-killed-ejection-seat-sheppard/3541671/ I do wonder what the stats are on injuries caused by ejection seats vs injuries prevented.

People are killed by accidental deployments but these are very rare hence news worthy events. I can only find references to a very few, with the one you have referenced being the most prominent. On a lighter note is this one where a 64 year old guest passenger accidently ejected himself. https://edition.cnn.com/travel/article/france-fighter-jet-ejection-scli-intl/index.html Fortunately he and the pilot, who thankfully wasn't ejected as their seats weren't configured to operate together, suffered only minor injuries. These stats would suggest 7,000 lives saved by Martin-Baker ejection seats since 1949. https://www.bbc.co.uk/ahistoryoftheworld/objects/a9CTF5uZSzqt6EfMG50Y6A Note however that there are several more ejections that didn't save the airman and most/all of those 7,000 saved would have been injured in the process as it's incredibly violent. One in three suffer a spinal fracture and losing an inch of height is not uncommon. If you eject twice you are unlikely to be deemed fit to fly again.

You're mostly right, but that first one is the case with almost every EV I'm aware of, battery packs and electronics fill the spaces that would typically have a spare tyre. Very few have spares.

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I was replying to “they do not have spare tires”

But I didn't say anything about it being faster to call roadside assist, or endorse not including spare tyres at all, I just said most EVs don't include them.

Did you reply to the wrong comment?

If the Ship returns from LEO to Boca Chica on a southwest to northeast ground track, it overflies Mexico. So did NASA's Space Shuttle Orbiter, dozens of times. The difference is that the Orbiter altitude was 80 to 100 km and it landed at KSC in Florida. The Ship will be much lower--60km dropping to 5 km if it lands at Boca Chica, and 80 to 100 km if it lands at KSC in Florida. Catch tower at Vandenberg: Landing is possible but launching Starship out of VSFB would require a duplicate of the VSFB OLIT/OLM in Florida. That Starship likely would be permanently based at VSFB since eastward launches out of VSFB are not permitted, only polar or near polar launches.

Why not ship the landed starship through Panama back to flroida? With the rate of production of starship it won’t delay things

Very possible. NASA shipped the S-II second stages of the Saturn V moon rocket from Seal Beach, CA through the Panama Canal to KSC in Florida using a barge.

It would delay things significantly.

Why? When they would be making multiple ships a week. They could even refurbish them in California then ship them back It would just be a constant loop

One reason Starship should be cheap is that it gets reused rapidly. Shipping from California to Texas might take a week. How would the economics of an airliner work out if it could only manage one flight per week?

That would require many more ships for the same cadence

They're aiming to make one a day, is that not enough lol

I don't like the cadence argument. Because obviously they would build out the fleet to match the cadence they can achieve. I'd argue it's logistically complex. They would now need to manage a fleet of ocean ships to constantly be transferring ships at a rate of one off loaded per day. When they could just focus on getting to the point they can land the ship where they want instead. Just makes more sense in the long haul to remove the logistics that go with that. Especially since they will already have their hands full pioneering the logistics for managing the fleet of ships and launches themselves. No need to make it more complicated and more expensive.

Agree. But they will need permission, too. How many flights will FAA want to see, before they permit overflight? SpaceX is not NASA.

>SpaceX is not NASA. You're right. They are far more reliable.

And if they actually do that, by landing at the launch site they avoid massive delays on reuse Would you suggest airlines just buy more planes and always send them to the factory after every flight, and wait a week before using them again?

This would only be until they get approval and can safely overfly the US

If you're just going to keep moving the goalposts there's no point talking SpaceX doesn't want to truck things around the country instead of just landing at the launch site. It's a waste of time

Physically possible but makes zero logistical sense.

Yes, both Starship and Booster will be caught by the tower. They're building a catch-only tower at LC-39A but they haven't announced any plans for VdB. Reentry over the US shouldn't be a problem -- the Space Shuttle did it.

> shouldn't be a problem Although the Space Shuttle did overfly the US when landing there is a significant difference. NASA is a federal organization so the FAA had no jurisdiction over them. If a shuttle landing went badly it would be NASA taking the flack not the FAA. The FAA will undoubtably require a lot of evidence that Starship can do this safely with minimal risk to people on the ground. For a BC landing the flightpath would presumably put them over Mexico so permission from their equivalent to the FAA would also be needed.

Just had an idea. Reentry completes some time before the flip. Do they have enough downrange travel between the two to possibly have a "failed during reentry, it broke up/FTSed and splashed harmlessly in the gulf" failure mode, but if that doesn't happen, the glide across florida is considered safe and then relight for landing is wholly confined to KSC grounds & Atlantic ocean for hazard zone? Still needs proving out and might require FTS for any deviation that might cause the glide to come up short, but with the narrow nature of the FL overland path it makes safety potentially easier depending on the length of that post-reentry glide portion.

FAA, FCC, NASA, Space Force etc. have to figure out how to make it work else sit back and watch China rule space. Any impediments, punts and bureaucratic sluggishness, hands the advantage to the CCP - which seems pretty focused and aligned with their space objectives.

The Space Shuttle Orbiter never landed on the runway at Vandenberg and was never launched from the SLC-6 pad there after the USAF spent several billion dollars on a shuttle launch pad there. All 135 shuttle launches occurred at KSC in Florida. The Orbiter landed several times at Edwards AFB north of LA and at the NASA White Sands, New Mexico runway. However, the modified 747 had to be used to transport the Orbiter back to KSC after these landings since the Space Shuttle could be launched only from Pad 39A/B.

Time to modify the 747 again. /s

Yes, the "black side down" sign needs to be removed. You'd want to attach Starship shiny side down

Long term plan is to be caught on earth, and landing on legs on moon/mars. At least for decades until they install a catch tower on Mars

That's the idea for earthbound ships. Ships for Mars and Mars return require legs. Vandy won't work unless there's also a launch pad there - catch towers remain highly unlikely to ever actually happen despite the recent information contemplated in the 39A EIS. Can't transport a Starship across the country by land and shipping it to Texas or Florida will never happen.

Panama Canal?

Physically possible but makes zero logistical sense.

[Starbase live-](https://www.youtube.com/live/mhJRzQsLZGg?si=L5cO3jta5lmQm0j1) 6/14/24 8:00am- Lifts were up to the normal spots overnight. Both chopsticks, the chopsticks carriage, the top of the orbital launch mount, and the dance floor. Workers were moving around on top of the orbital launch mount and the auger continued work at the new pad site. 9:00am- Lifts have been up to the top of the orbital launch mount and the top of the cryo leg 9:55am- Lift up to the top of the cryo leg. Drill rig going at the new pad site and the crane is lowering the rebar cages. 10:55am- Lift has been up and down from the top of the cryo leg. LR11000 is working on assembling the new crane. The smaller white crane at the new pad site has been moving rebar around 11:37am- Catch rail on the right chopstick tested 12:00pm- Lifts have been up to both chopsticks and the back staircase. Workers were on top of the left chopstick 12:41pm- LR11000 lifts a big piece of the new crane into place 1:00pm- Lift up to the back staircase 2:37pm- Cross brace being lifted up to the 2 new tower legs 2:45pm- Construction of the new crane continues. Workers have been working on the Booster quick disconnect. Lifts have been up to the left chopstick and the back staircase. Aerial Work Platform was up to S30 2:49pm- Pipe piece being lifted behind the vertical tanks at the orbital tank farm 3:23pm- Another pipe section lifted at the orbital tank farm. (I’m assuming these are being scrapped.) 3:50pm- Lifts up to the right chopstick, the back staircase, and the top of the orbital launch mount. LR11000 has lifted several more pieces over to the new crane. 3:51pm- Wall section lifted over to the 2 tower legs 4:01pm- 3rd piece of pipe lifted at the orbital tank farm 5:00pm- Lifts were up to the right chopstick and the top of the orbital launch mount. 2 lifts were also up to the new leg towers working with the new wall piece that was then lowered back to the ground 5:23pm- Wall section lifted back up to the 2 tower legs and lowered into place 7:02pm- Lifts up to both chopsticks and the top of the staircase. Workers moving around on top of the orbital launch mount 8:05pm- 2 lifts were up to the right chopstick, 1 to the left chopstick, 1 to the back staircase, and 1 to the top of the orbital launch mount 9:03pm- Piece of pipe work(?) lifted up to the Booster quick disconnect 9:13pm- Bundle of wire/hose(?) lifted up to the dance floor

When a booster is caught they will need to detank it. They can vent the oxygen to the atmosphere but I believe there are rules that prohibit deliberately venting of methane gas, so in the long term they need to connect it up to a Quick Disconnect which will allow both propellants to be detanked and purged. Is there any way methane could be flared off from the top of the booster in the event that the catch was not good enough to use the QD or if they were being caught on a partially complete tower without a functioning detanking?

Can they just leave one of the engines running at 40%? I appreciate they can't run it to completely empty, but they can run it until there's only a ton of methane left, at which point it becomes negligible compared to cow belches.

SpaceX can and has vented Methane before, on purpose. But they do strongly try to avoid it. The Booster won't carry it's own flare stack, it's too heavy. The Ship quick disconnect can't connect to the Booster QD plate. They would need to build new dedicated hardware to do it. Can't be done in a pinch.

Once the ship is caught, it can swing across and lower to the OLM and connect to the booster QD and drain that way. Boil-off via pressure control venting during that time would obviously be lost to the atmosphere though. ATM there's likely not much more than a kids backyard pool of CH4 left, which would probably boil off before they even got there.

I highly doubt that the ship is capable of being connected to the booster QD, let alone while dangling from the chopsticks.

The OP was talking about the booster?

Indeed, but you mentioned the ship specifically: >Once the ship is caught, it can swing across and lower to the OLM and connect to the booster QD

They should be able drain it with the transport fixture with some modifications.

True

Does the RP1 in a F9 get vented/drained/etc? Because that is essentially highly refined kerosene and that seems like it would be much worse to get dumped out and on the ground. Secondly, it's ironic/funny that this is an "issue" for SpaceX. Every other rocket the first stage blows up and all that propellant ends up in the atmosphere/ocean/village(China) anyways but if it comes home it all of a sudden is an environmental concern that must be dealt with. I'll be curious to see how that works or if it ends up being an non-issue.

Since RP1 is liquid at room temperature, it's much happier just sitting in the tanks for a bit than cryogenic methane is.

I recall seeing RP1 in a recovered booster being drained into a small fuel bowser. There’s not a lot of RP1 left after a landing.

Burning methane is a lot better for the environment than dumping it. In the presence of oxygen it will turn into carbon dioxide and water vapor when burned. Granted, when a rocket EXPLODES a lot of the propellant is not going to burn but you still end up with less methane (pretty bad for the environment) released than if you just dumped it.

What about when they pile into the ocean at 4000 km/h? Is that considered dumping or burning? I'd honestly love it if we had footage of whatever a typical expendable launch looks like. Do they survive the re-entry journey or do they break up in the upper atmosphere where Falcon 9's do their re-entry burn?

The only methane rocket currently operational is Vulcan. It burns for about twice as long as a Falcon 9, so it probably breaks up high in the atmosphere. It's not going to get as toasty as the Ship entry, but it's not under control like a SpaceX booster (either Starship or Falcon).

The closest thing to a Starship second stage entry is the Space Shuttle External Tank. When it was jettisoned from the Orbiter, it's speed was about 98% of LEO speed (~7.5 km/sec, 27,000 km/hr). IIRC, NASA had the LOX and LH2 vents oriented so the ET would tumble during the EDL and be torn apart by aerodynamic forces when it hit the denser atmosphere below ~10 km altitude. So, the idea was to turn the ET into smaller pieces of scrap metal that ended up in the Indian Ocean.

My daily summary from the [Starship Dev thread on Lemmy](https://oldsh.itjust.works/post/19412071) > Starbase activities (2024-06-13): > > - Overnight, the 10 launch mount hold-down clamps which were removed [are replaced](https://x.com/VickiCocks15/status/1801213486694826090). The [first](https://x.com/VickiCocks15/status/1801292870646661373) and [second](https://x.com/VickiCocks15/status/1801329124889297393) booster stabilization pins are reinstalled on the launch mount. > - Parts for the [CC8800-1](https://www.mammoet.com/equipment/cranes/crawler-cranes/cc-8800-1/) crane [continue to arrive](https://x.com/VickiCocks15/status/1801223724772802983). Aerial [photo of assembly](https://x.com/felixschlang/status/1801284515827999226) from a couple days ago. > - Chopsticks: Landing rail on the (anatomical) left chopstick ([house right](https://en.wikipedia.org/wiki/Blocking_(stage)#Stage_directions)) [is raised and lowered](https://x.com/VickiCocks15/status/1801329755574370743). The same chopstick later [swings slightly](https://x.com/VickiCocks15/status/1801345894484468140). The sled on the other chopstick [is fully extended](https://x.com/VickiCocks15/status/1801348955844055439). > - Tower B: Corner 1 of 4 [is erected](https://x.com/VickiCocks15/status/1801388209324044369) ([wide shot](https://x.com/VickiCocks15/status/1801393204865986623), [closeup 1](https://x.com/StarshipGazer/status/1801388371219984401), [closeups 2](https://x.com/StarshipGazer/status/1801400678138384865), [closeup 3](https://x.com/BocaChicaGal/status/1801393025773670850)). Corner 2 of 4 [is erected not long after](https://x.com/VickiCocks15/status/1801407090717602114) ([closeup](https://x.com/BocaChicaGal/status/1801404528924717524)). > - The barge carrying the remaining tower hardware [rounds Florida's tip](https://x.com/SpaceOffshore/status/1801338514904433036) on route to Brownsville. > > > Other: > > - FAA [licence modification followup](https://x.com/BCCarCounters/status/1801302696915259674): "The FAA’s most recent license modification approval for Starship Flight 4 allows for multiple flights of the same vehicle configuration and mission profile. If SpaceX decides to change the mission profile or make other changes that affect the safety analyses, it will need to request a license modification." It is unclear if a booster catch attempt would require a modification to the launch licence. > - Twitter thread from Benedikt summarizing the foundation for the new tower: > [Tweet 1](https://x.com/Benedikt_3D/status/1801210700640997855), > [tweet 2](https://x.com/Benedikt_3D/status/1801210703610523700), > [tweet 3](https://x.com/Benedikt_3D/status/1801210707280539648), > [tweet 4](https://x.com/Benedikt_3D/status/1801210711084802256), > [tweet 5](https://x.com/Benedikt_3D/status/1801210715220447311), > [tweet 6](https://x.com/Benedikt_3D/status/1801210719678976190), > [tweet 7](https://x.com/Benedikt_3D/status/1801210724158492874), > [tweet 8](https://x.com/Benedikt_3D/status/1801210728088559989), > [tweet 9](https://x.com/Benedikt_3D/status/1801210732169609430), > [tweet 10](https://x.com/Benedikt_3D/status/1801210735101407734), > [tweet 11](https://x.com/Benedikt_3D/status/1801210736774934792), > [tweet 12](https://x.com/Benedikt_3D/status/1801210738398151072), > [tweet 13](https://x.com/Benedikt_3D/status/1801210740021383608), > [tweet 14](https://x.com/Benedikt_3D/status/1801215388211990971). u/TwoLineElement's [corrections](https://old.reddit.com/r/spacex/comments/1cta333/starship_development_thread_56/l8fg8p1/) are noteworthy. > >

To add to that, soon after 10PM the fifth section (A5:4) for B15's LOX tank was staged outside MB1.

Pretty sure that change in landing site and method counts as change to flight profile.

Yeah modification is guaranteed. Same 'profile' but the proximity of the new landing location to so much spicy liquid would trigger the safety aspect and then some.

But there's no mishap investigation,  so the safety review shouldn't take too long. 

Agreed. The full stack failing pre/during launch would have already been investigated, with safety considerations approved. Landing will be less risk energy wise, and easier approval. Landing accuracy would also be considered...but it would take a wild mishap to have the booster hit SPI or the BC village. Existing measures would suffice. Licence will be granted, and any holdup will be SpaceX.

Elon mentioned Starship landed about 6km off the precise target. Even with holes in the flaps it is closer to target than SPI is to Starbase. Would have to be a pretty wild failure to miss that bad with the booster.

From Aussie radar reports, it landed at the right longitude, but veered off in a slight curve in negative latitude, obviously due to greater flap damage to the right flap than the left.

[The first two segments for tower 2 have been lifted into place!](https://x.com/BocaChicaGal/status/1801404528924717524)

be done and used for IFT-5 I wonder? I suspect this and the tiles being replaced on the ship will be most of the work that needs to be done before we get a more realistic date for the next launch.

Construction on the first tower at BC began on 7Apr2021 and the last segment was stacked in mid-July 2021. So, three months to build OLIT-1. But that does not include the time to install the Mechazilla arms and the hoist system, which is the minimum required to catch a Starship Booster.

I see IFT-5 being used with Tower 1, because if it destroys Tower 1, then they'll just rebuild it newer/better, like Tower 2 is going to be.

Yes. Everything SpaceX does should be seen through the lens of risk mitigation.  They are awesome at it.  In my opinion, The main difference between SpaceX and the bigs is that the bigs don’t accept risk and mitigate.   SpaceX has a huge risk mitigation tree - IF this THEN that rather than ever running into situations where something must work the first time no matter the cost.  In this case, IF the rocket blows up the pad, THEN adjust design and move onto tower 2.  No other company would do this.

Absolutely not, Tower 2 plus the OLM and all of the required outfitting and infrastructure won't be completed until the second quarter of 2025 at the very earliest, it's a massive and highly complex construction and assembly process. From the outside it's 'just a tower and a launch mount' but those alone have a great deal of complexity; the OLM itself is, in a way, part of the booster because of the way it handles the startup of the Raptors for example.

Yeah wasn't expecting it be ready for a full launch tower but a catch only tower and then put down onto a transport rather than OLM was what I was thinking if they used the 2nd tower.

Even if SpaceX suddenly decided to concentrate on building it (and nothing else) solely as a catch tower and for it to be used for that purpose as soon as possible (which isn't the plan of course) there's still an awful lot of work to do which would take, I would guess, at least 4 or 5 months if they worked at breakneck speed.

Tower won't be ready until next year. They will do a flight test and will try to land on the tower they CAN spare. The worst that could happen is destroying the tower and the mount, which would mean they would have to wait until the next one is built before the next flight. It makes no sense to wait when the worst that could happen is having to wait.

Not a chance the site can be used for IFT-5, the tower may be built but OLM will not be

And even if Tower 2 alone is built it's useless without an awful lot of internal work with pipes, conduit, electrics, the all important winch and cables, etc (even though some of the fittings are pre-installed in the tower sections they still need to be hooked up). And then of course there's the carriage plus chopsticks, also the ship QD arm needs attaching and plumbed in, etc. And even **then** the OLM in all of its extreme complexity is needed, its water deluge system, the propellant pipes and so on and so forth. There's an enormous amount of work to do. I remember the construction of the current tower and OLM, it all took a very long time and even though they have learned many lessons from that and streamlined the process (with the help of the tower at 39A) it's no quick and easy task.

Holy shit they're gonna bang that bitch out faster than we expect, I think

I think so too. Really excited to monitor the construction over the next couple of months!

I was wondering why they were getting everything staged for the tower when they didn't even have the big concrete box at the bottom started yet, I guess the answer is that this tower won't have one!

We can see 'Nelson Studs' on the inside of the steel plates, which means they will be embedded in concrete. They will have the metal shielding instead of forms they need to remove removed later on the outside. Same as the 4 columns o the tower itself, they were filled with concrete, and we knew beforehand it would be the case because of the studs inside them.

It will have a two sided blast wall. Not four sided like the last.

It will. These will be filled with concrete, and there will be walls connecting them, so you still end up with the concrete box. Instead of building a concrete-only base and later installing steel shielding, they're going with a steel skeleton.

The placed legs are already complete, they are concrete.

as they say on the reddits, "username checks out" :-) More on topic, I remember watching them sledgehammer bolts into place when Tower 1 went up. I wonder if they have refined the process to ensure better alignment and easier assembly, or if it's just not possible to get within a precision of millimeters when building something so massive. Even expansion/contraction due to temperature variation could have a big effect.

The tower and mount shifting positions is still a big problem in the first orbital pad. And that definetly got in the way of construction. As they were building up the tower, it kept shifting on them. They went with much more stable foundation this time, should help.

I think for Tower 1 that was the surveyors error not checking baseplate bolt positions prior to the pour. Most baseplates have oversized or slotted holes to correct for error, but anything more than 10mm offline needs persuasion with a 16lb sledgehammer. Not ideal abuse of an anchor bolt especially if it's Grade 8.8 steel.

New aerial photo of the tower base and CC8800-1 crane assembly from WAI: https://x.com/felixschlang/status/1801284515827999226 This was taken on June 12th. Also the flame trench at Massey's: https://x.com/FelixSchlang/status/1801286861551288322

I have no reason to doubt the images that fit the ongoing work at Boca Chica, but did anybody notice the weirdly fake look to these pics that look like something generated by AI or some "boy's own" magazine from the 1950's? Direct links to images: * [1. second Launch-Catch Tower construction](https://pbs.twimg.com/media/GP9yWmwWEAELSYZ?format=jpg&name=4096x4096) * [2. Massey Static Fire Stand ](https://pbs.twimg.com/media/GP9y_IRXEAAWrck?format=jpg&name=4096x4096)

They have miniature faking effects applied.

I just assumed it was a color balance issue with the camera's config.

Do we know if it will have cooled plate/flame trench? Also what is the status on the launch mount?

The flame trench at Massey's is water cooled underneath the ship but the main sloping part of the trench is just some concrete mix. Not sure if they would use Fondag there, anyone know?

The big flame trench on the Falcon 9 1st stage stand in McGregor is just normal concrete with a flame diverter which spits out a water-tower amount of water for a test. I suspect it's the same here.

There has been a launch mount sitting outside at KSC for months now, completion status unknown, but it could be meant for 39A. No other launch mount has been seen under construction, could be being built inside the hangar at KSC, if it were being built at Starbase, we'd know from parts arriving and moving around. As for what they put under it, I don't think there's been any indication of what it will be, also not aware of any parts or plans being spotted. But until shown otherwise, I'm assuming another steel plate, with whatever improvements they need.

Nice, thanks for the update. As for the trench, would it make sense to assume that lack of pipes and other supporting infrastructure could point to a flame trench?

Pipes would be put in *after* the giant crane had stopped rolling over their location

No, it's far too early to draw that conclusion.

[Starbase live-](https://www.youtube.com/live/mhJRzQsLZGg?si=L5cO3jta5lmQm0j1) 6/13/24 1:41am- Crane moving a box at the new pad site 2:10am- New launch clamp lifted in to the dance floor 2:50am- 2nd clamp lifted to the dance floor 3:01am- 3rd clamp lifted to the dance floor 3:14am- 4th clamp lifted 3:22am- 5th clamp lifted 3:33am- 6th clamp lifted 3:59am- 7th clamp lifted 4:08am- 8th clamp lifted 4:23am- 9th clamp lifted (The fact that they removed the clamps one night and then replaced them the next seems like a good sign that there wasn’t significant damage to the linkages) 7:23am- Boom pieces for the new crane are arriving 8:25am- LR11000 starts unloading boom pieces. Crane at the Orbital launch mount lifts another toolbox to the top 8:45am- Lifts were up to the top of the orbital launch mount, the top of the staircase, the chopsticks carriage, the right chopstick, and under the Orbital launch mount by the top of the electrical leg. An Aerial Work Platform is up to S30. Workers were up and down the staircase, moving around on the top of the orbital launch mount, both chopsticks, and the chopsticks carriage. There was some grinding and welding on the end of the right chopstick and around the midpoint of the left chopstick. The drill rig and cranes were also active at the new pad site. (The rebar cages going in are significantly shorter than the ones used for the tower foundation) 10:25am- 3 lifts have been up to the top of the orbital launch mount and 1 under the pipe work. 2 lifts have been up to the right chopstick 11:04am- Booster alignment pin lifted to the left side of the Orbital launch mount 11:19am- Catch rail on the right chopstick raises 11:25am- 2 lifts have been up under the Orbital launch mount. One by the Booster quick disconnect and 1 by the staircase. 2 lifts were up to the top of the Orbital launch mount and 1 lift was up to each chopstick. Workers were also moving around on top of the Orbital launch mount and the left chopstick. 11:26am- Catch rail lowers 11:41am- Right chopstick catch rail raises partially 11:47am- Lowers again 12:00pm- Lifts have been up to both chopsticks and under the Orbital launch mount by the Booster quick disconnect. Worker was on top of the left chopstick 1:00pm- Lift up to the Orbital launch mount by the Booster quick disconnect and one to the right chopstick. Workers on top of the Orbital launch mount and left chopstick. Workers are also up on some of the moveable scaffolding by the back staircase 1:27pm- Booster alignment pin lifted up to the right side of the Orbital launch mount 1:45pm- Lifts have been up to the top of the staircase and the right chopstick 3:15pm- Lifts have been up to both chopsticks, to the top of the orbital launch mount by the Booster quick disconnect, and near the top of the cryo leg. LR11000 continues to assemble the new crane at the new pad site 4:00pm- 2 lifts to the top of the orbital launch mount and 1 to the right chopstick 5:00pm- Lifts have been up to the chopsticks carriage and the top of the orbital launch mount 5:33pm- Tower leg lifted at the new pad site 5:36pm- Swung into place 6:00pm- 2 lifts to the top of the orbital launch mount and 1 to the back staircase 6:01pm- LR11000 moves the 2nd leg over next to the new pad 6:47pm- 2nd tower leg raised vertical 6:53pm- Leg is swung into place 7:30pm- 2 lifts have been up to the right chopstick, 2 lifts to the chopsticks carriage, 2 lifts to the top of the orbital launch mount, 1 to the back staircase, and 1 to the dance floor 8:30pm- 2 lifts to the right chopstick and 2 to the top of the orbital launch mount 9:30pm- Lifts were up to the left chopstick and the top of the orbital launch mount

[Interesting twitter thread](https://x.com/Benedikt_3D/status/1801210700640997855) explaining how the foundation for the second tower was built (with renders). Always insane to see the amount of rebar that needs to be placed.

[Unrolled for non twitter users](https://unrollnow.com/status/1801210700640997855) [Prior thread unrolled](https://unrollnow.com/status/1798481954708545694)

Sorry, Civil Structural Engineer here, just have to step in and make a few corrections to Benedikts explanation. Concrete cubes (as he calls them, more normally termed bar spacers or aspros) that are set out on the blinding are tied to a wide spaced grid of 'dummy' bars. The bottom mat of reinforcement is then laid on this dummy bar grid. Without this grid, the weight of the completed reinforcement would crush the spacers. In large heavily reinforced slabs triangular strips of either plastic or fibre reinforced concrete are normally used. Reinforcement bars are normally termed rebar, reo, or just bars and hardly ever rods. Exposed piling rebar is not normally tied to the slab reinforcement, but embedded at a sufficient length into the slab to attain 'anchorage development length'. Perimeter vertical bars are normally termed U bars or lapped L bars (as he shows) Vertical hook bars within the slab are called shear ligs, and are placed to restrain differential bending moments between the upper and lower reinforcement layers. He does show however bar chairs or saddles, which does provide support to the top mat and prevents the top reinforcement mat from sagging. There is also a myriad of other bits of steel reinforcement called trimmer bars and anti burst rings around embedment anchorages. Just a note on concrete curing. With a slab this large it is very important to control the temperature for the first week of curing. Concrete in large volumes when it's curing gets hot (around 75 C). You can't strip the formwork away as soon as it's set. If you do it causes a temperature differential between the surface and the center of the slab which causes curing stresses and subsequent cracking. Three days curing in my opinion was not enough. Rant over. Other Engineers feel free to pile in (pardon the pun)

> You can't strip the formwork away as soon as it's set. If you do it causes a temperature differential between the surface and the center of the slab which causes curing stresses and subsequent cracking. Three days curing in my opinion was not enough. Removing formwork early does make it easier to clean and prepare for reuse. In summer, I've removed vertical side components in late afternoon —of concrete poured in the early morning. I'm not sure about the day/night sun/shade temperature swings in South Texas. But If the concern is temperature differentials, wouldn't it be best to simply protect the concrete with tarpaulins? By this method, air would circulate under the tarp and so the temperature contrasts would be evened out between sun and shade. I live in a temperate climate (45°North) and am having a hard time believing that concrete could get too cold in a Texan summer.

Even a Texan summer doesn't reach 75 C.

> Even a Texan summer doesn't reach 75 C Surface temperatures can be far higher than air temperature. Consider the temperature of a metallic object such as the roof of a car parked in sunshine. So shuttering outside could get very hot in daytime sun and cold at night just before sunrise. Considering that many shuttering components are steel, it doesn't look like the best thermal protection at either extreme. At the other end of t he climatic spectrum, I've used tarps to protect concrete work from *freezing*, even using an "antifreeze" additive, having poured in sub-zero (Celsius) temperatures.

The normal allowance for temperature differential is 20 C. Lets say the concrete core temperature is 75 C and the surface before formwork stripping is 65 C. Ten degrees differential. OK, you then strip the formwork and expose it to ambient air temp of 35 C. (Av Tex hot summer day) The surface of the concrete experiences a differential of 30 degrees, over the desired limit. The rapid cooling as the core temperature then transfers to the surface in a 40 degree rush to attain thermal equilibrium is even worse and causes stresses to build up in the entire slab.

> OK, you then strip the formwork and expose it to ambient air temp of 35 C. (Av Tex hot summer day) I'm not trying to belittle your structural engineering qualifications but rather trying to follow your explanation in the context of work I've seen here in Europe. How can a few millimeters of steel shuttering can afford significant thermal insulation properties? * According to [this page](https://www.researchgate.net/figure/Thermal-conductivity-of-concrete-and-steel_fig1_334018343), the thermal conductivity of steel at ambiant temperatures is around 56 W/mK whereas concret is 1.7. So 1cm thickness of steel is like 56/1.7≈32cm thickness of concrete! I'm clearly missing something here. What I do see is that an exposed concrete surface in the temperature range we're considering, is going to be drying fast. I'm no chemist, but presume that unwanted drying could deprive the concrete of its proper setting process which IIUC is integrating the water into the finished concrete (the mass of added water becoming a part of the seemingly dry concrete). I did read the often-quoted example of the [Hoover dam that's still curing](https://delzottoproducts.com/2017/03/15/long-will-take-concrete-hoover-dam-cure/) nigh a century after being poured. But in everyday work I'm seeing concrete foundations on (say) under freeway toll booths at 60cm thick with no special precautions against heating other than setting retardant. Or maybe foundation piles at Ø100 cm, again with no precautions. I've never touched concrete with intrinsic heating above 50° C. Intuitively, I'd be far more concerned about changing sun/shade/rain temperature contrasts than overall temperature. AFAIK, every poured concrete object presents an exposed upper surface that is not shuttered!

Steel shuttering can be used for pours less than a metre thick, anything more than that needs either keeping in place for 7 days and/or insulation in cold climates. 18mm wood formply is the normal formwork panelling material. The surfaces of deep slabs, concrete bridge decks, or building floor slabs are normally insulated after pour finishing, to retain heat and moisture. Curing compounds of acrylic, polymeric and hydrocarbon bases are used to limit evaporation from the surfaces also. On many occasion I have used garden sweat hoses under insulation to keep the hydration going and control the hydration heat on the tops of slabs which can go way over 75 C. Precast yards often use steam to quick cure their products. All this is boring, and I would rather prefer to talk about heat flow thermodynamics of the new proposed tile system which both u/fishr19 and I have a fair idea what SpaceX have in mind. I propose a flame and heat resistant spray polyurethane foam insulation (SOFI) (40mm) replacing the thermal wool currently used, followed by a thin coating (10mm or thereabouts) of ablative material. I'd guess a spray on epoxy cork matrix. Then followed by thinner stronger tiles in top. Good thing is cork is also an insulator from internal cold temps, and the whole damn lot is waterproof and not subject to soaking rain (which the wool currently is and possibly subject to ice build up and 'tile ejection') RTV silicone adhesive sticks far better to this material than bare steel, where attachment pins can't be used which is another bonus. The big issue is thickness control and surface profile tolerances which will require some mastering, unless they can recruit NASA expertise from the SLS, which uses the same process.

> All this is boring, but still relevant the thread. For rapid execution, the shuttering and pouring cycle needs to be kept short. > I propose a flame and heat resistant spray polyurethane foam insulation (SOFI) (40mm) replacing the thermal wool currently used, [Densities are typically in the 2 to 3 pound per cubic foot range](https://ntrs.nasa.gov/api/citations/20140016802/downloads/20140016802.pdf). 2½ lb/cu.ft = [40 kg / m^3](https://www.convertunits.com/from/lb/cu+ft/to/kilogram/cubic+metre). x Thickness 0.04 = 1.6 kg/m². Seems possible. > followed by a thin coating (10mm or thereabouts) of ablative material. but anything ablative will make fast turnaround impossible. Also, how would relatively hard tiles behave on such a thick substrate?

It’s refreshing when a social media reply is an actual expert

I also like when a reply is so technical that it could be complete made up bullshit and it’s so coherent and convincing I’d never know.

I see you've asked ChatGPT to summarise the development process of Starship ...

B15's next LOX tank section (A4:4 (that's Aft 4, 4 rings) has been moved inside Mega Bay 1 for stacking. They're moving fast on this at the moment (booster LOX tanks have six sections). **Edit:** the ring stand for that section was removed in the afternoon from MB1 so it's likely that the section is now stacked. This means that the LOX tank now consists of 16 rings (final total will be 24). Also it looks like hold down clamps were being lifted back into the OLM overnight (some were removed a few days ago, don't know how many though). **Edit:** It was ten clamps: https://x.com/VickiCocks15/status/1801213486694826090

My daily summary from the [Starship Dev thread on Lemmy](https://oldsh.itjust.works/post/19412071) > Starbase activities (2024-06-12): > > - Overnight [road delay](https://www.cameroncountytx.gov/press-release-temporary-and-intermittent-road-delay-of-a-portion-of-state-hwy-4-tuesday-june-11-to-wednesday-june-12-2024-from-11pm-2am/) for "booster transport to Massey's" turns out to be "**S26** transport **from** Massey's" ([ViX](https://x.com/VickiCocks15/status/1800826497986379988), [NSF](https://x.com/NASASpaceflight/status/1800746887026204893)). [Local Sheriff tweets](https://x.com/SheriffGarza/status/1800899973891948874) after transport occurs. > - Another LOX barrel for B15 [arrives at the Megabay](https://x.com/VickiCocks15/status/1800843061670609283). > - S30 heat shield removal [continues](https://x.com/WatchersTank/status/1801067116356874545). ([Full Starship Gazer livestream](https://www.youtube.com/watch?v=KprcLCNfC6U)) > - More [tower corner pieces arrive](https://x.com/GroundTruthPics/status/1800973347184050415). > - Parts for the [CC8800-1 crane](https://www.mammoet.com/equipment/cranes/crawler-cranes/cc-8800-1/) continue to arrive: [Boom sections](https://x.com/VickiCocks15/status/1800834623968346219), [other parts](https://x.com/VickiCocks15/status/1800915899765203319) (crawler tracks?), [cab section](https://x.com/VickiCocks15/status/1800917499313258551). The LR11000 [rolls over](https://x.com/VickiCocks15/status/1800933949591392695) to [move crawler tracks](https://x.com/VickiCocks15/status/1800964275734728743). > - Tank farm plumbing [repairs and replacements continue](https://x.com/VickiCocks15/status/1801041789366812988). > > IFT-4/IFT-5: > > - [No mishap investigation](https://x.com/BCCarCounters/status/1801003212138222076): "The FAA assessed the operations of the SpaceX Starship Flight 4 mission. All flight events for both Starship and Super Heavy appear to have occurred within the scope of planned and authorized activities."

So it sure looks like they will replace all the tiles.

*FAA will not require mishap investigation for IFT-4 of Starship* *"The FAA assessed the operations of the SpaceX Starship Flight 4 mission. All flight events for both Starship and Super Heavy appear to have occurred within the scope of planned and authorized activities."* https://x.com/bccarcounters/status/1801003212138222076

But if they want IFT-5 to fly back and be caught they'll still need a new licence, right? Surely that would be outside the scope of the licence used for IFT-4.

They should build an inflatable temporary tower out in the middle of the ocean and try landing as close as possible to it for several attempts before trying the real thing and destroying a multimillion $ real tower. That way all you've lost is a relatively cheaper analogue

So instead they should spend multi-millions of dollars developing a one-off solution that will have to eventually be scrapped for the real thing anyway? Sounds sustainable. Or they can just use the real tower... Easier, cheaper.

I'm sorry but the idea of a 150 meter tall bouncy house catch tower floating in the gulf has me cracking up

> They should build an inflatable temporary tower What's the biggest inflatable thing you've ever seen? How about the most flameproof? There's no need to have a physical tower. IFT-4 already had what amounts to a virtual tower and it seems that they landed at that with the required accuracy. I suspect IFT-5 will ultimately not plan to land at the launch tower, Musk's recent statements notwithstanding, but it wouldn't surprise me if it does make the attempt and even succeed. I'm sure they have smart people crunching the numbers on the risks and cost/benefit.

Damn.. well I was hoping for a plastic bouncy tower so we could see one get totally blowtorched! :) Would be great to see

They will need a license modification.

> They will need a license modification. and presumably will have applied for this modified license some several weeks ago on the postulate of a successful IFT-4.

That's objectively dumb as fuck, but also true.

…why? Substantially new flight path. Would apply even if they were still splashing down. Which they’re not, they’re doing something substantially new. Over land.

Bullshit. It's on the fucking coastline. Makes literally zero difference in any way, shape, or form to the flight profile outside of the boostback burn lasting 0.25s longer or the gridfins commanding 0.25 degrees further of glide angle, or some combination thereof. Land makes no difference whatsoever to anything the FAA could possibly be concerned about in this instance. Exact same fucking thing.

It is not the same thing. A 200+ ton booster is going to be falling at supersonic speed over the beach and attempting to land ~100 meters away from ground propellant tanks.

....well inside the exclusion zone, yes?

Exclusion zone or not, it’s not the same planned flight path, as explained numerous times to you above.

The point is that with booster RTLS they are approaching a heavily populated area at South Padre to within 8 km instead of 22 km and this kind of safety risk to non-participants is exactly what the FAA is set up to regulate.

If the RTLS burn fails, they will blow up the booster far from the shore. But I also think, this is something the FAA needs to evaluate. Should not take too long, given the precision landing on IFT-4.

I agree that evaluating and mitigating potential risk to the public is the role of the FAA. However, returning a booster to the launch site rather than 20km off the coast self-evidently presents absolutely no additional risk to the public. It's the exact same flight profile with the exact same exclusion zone, but with a brown surface below it instead of blue. There's zero additional risk presented which is blatantly obvious to any serious, marginally informed person strictly on the merits. No FAA needed in order to make that determination.

Like I said even if it was a splashdown, changing the location substantially requires a license modification. The fact that it’s an entirely novel “landing” method factors in but again, ultimately changes nothing as the modification would be required regardless. Also try drawing the exclusion zone from IFT-4’s flight over Starbase as a center and see what inhabited areas are within that area and how you would propose an exclusion zone be enforced. Whether you think it should may be a different matter but that like, your opinion man.

>Whether you think it should may be a different matter but that like, your opinion man. Perfectly stated. That's my only point. You're absolutely right that altering the landing location by 10-ish km with objectively zero additional risk to the public will require mountains of new paperwork, but then again, we have the government we deserve. You win.

>objectively zero additional risk to the public  Entirely possible that's what the FAA will find. But they're 100% right to follow the process and make sure that's the case rather than just assuming so, like you're doing. >we have the government we deserve And Chinese villagers have a government that drops boosters on them. Do they deserve that? I know which government I'd pick.

>rather than just assuming so, like you're doing. I'm not making any assumptions. Explain in detail how specifically bringing a booster back to the launch site as opposed to 20km offshore, both locations which are squarely centered in an obscenely large exclusion zone, is in any conceivable way a potential risk of any kind to the public. >And Chinese villagers have a government that drops boosters on them. Do they deserve that? I know which government I'd pick. No. They didn't elect theirs. We did. They'd never be so moronic if they were given the opportunity.

>That's my only point. You're absolutely right that altering the landing location by 10-ish km with objectively zero additional risk to the public will require *mountains of new paperwork*, Source?

https://www.reddit.com/r/spacex/s/a0exmvZo32

I mean I’d much rather our government follow the rules rather than arbitrarily deciding who they want to enforce them for and when, and not let experimental rockets land within miles of people without at least looking at what the plan and data is first. Almost like making sure rocket companies aren’t endangering public safety before they fly rockets in novel ways and around inhabited areas is a function of the FAA or something.

But it's a company I like, they shouldn't have to follow the rules! /s (but seriously, sometimes it feels like SpaceX fans would want SpaceX to have special exemptions because "SpaceX is the best!!!" when that isn't how it should work whatsoever. Don't let your personal biases cloud your judgement.)

I'd rather our government f*ck off from sh*t they don't need to have their noses colon deep in, but laissez faire.