Ultimate Steve

Everything about a potential failure cause in the NSF flight 7 discussion thread (https://forum.nasaspaceflight.com/index.php?topic=61945.480) from around page 8 until Elon tweeted about the suspected root cause: Everything in the NSF flight 7 discussion thread after Elon tweeted about the suspected root cause, through like halfway ish through page 25, which is the current end of the thread as I write this: It seems to be a lot of speculation with the same amount of information as we have and a little more competence than we have, except for possibly some new information from the tweets from @DutchSatellites on Twitter/X . I am not sure how qualified this guy is. Scrolled back a little and didn't really come to any solid conclusions and I've already scrolled enough today. I asked on one of the spaceflight-adjacent Discord servers I am a part of if they had heard anything similar, or if they thought this guy was credible, and one person thus far has responded saying that this guy is usually credible but has no idea about this specific piece of information. It hasn't even been four days. I also expect that they at least know the general area (and possibly the exact area) by now but I wouldn't go as far to say that there is no doubt. Again with the whole "No doubt" thing. Maybe this is a me thing but I'm rarely so certain about anything. Have a little imagination. It isn't quite that cut and dry, during the suborbital test campaign the engine section looked like this: And in this configuration they were able to get this sort of camera view: I can't find any good and easily accessible pictures of the new arrangement besides this image from integrated flight test 1, but to my knowledge, the shielding they added is still present on the current generation of vehicles (someone I know recently affirmed this for my recent gimbal calculations), though I could be wrong: The existence of an enclosed space (between this shielding and the tank dome) tracks with the whole thing about an overpressure due to not enough venting causing all engines to fail (which I don't see a reasonable path towards occurring if there was no enclosed space enclosing plumbing related to each of the engines). Notably neither of these camera views are thought to still be available. The first one because the shielding blocks the view, the second one because the addition of the hot stage ring blocks the view (not that it would help much for anything besides stage separation and the couple seconds afterwards). This is the only camera angle in the engine bay that (at least one of) the Starships in the orbital test is/are confirmed to have (in space relight on flight 6): Which is quite lower in order to be able to peek through the shielding, and as such does not have as good of a view of the engine bay as the cameras did during the suborbital test campaign. They (nearly) certainly have camera angles we do not know about but we do not know how many if any are inside the engine bay, or above the engine shielding. Notably with those sea level Raptors in their own cubbies, it might be pretty difficult to image those engines at all, even from cameras inside the engine bay, unless you had like 6 cameras looking down into the cubbies, 2 per engine, along with internal lighting. And then more cameras for the rest of the engine bay. And who knows, they might have done that. Granted, they (nearly) doubtless have loads of sensors that aren't cameras over every inch (every square inch is hyperbole but you get the point) of the vehicle. But we do not know for certain that they have the same cut and dry visual confirmation that they had during the suborbital test campaign. They should not, and the current likely cause is in the new plumbing. We do not currently know the source of the leak for sure but we do know (unless of course SpaceX are lying to us in their official statements): The fuel feedlines for the vacuum Raptors were completely redesigned this flight The fuel feedlines (unclear if this is just Raptor Vacuum or also Sea Level Raptor) were redesigned to add vacuum jacketing And we have the following things that might have happened but I don't currently have hard evidence for: A lot was redesigned for Starship V2, additional propellant feed system tweaks are likely Starship V2 might be designed with Raptor V3 in mind, something on the vehicle side or the engine side might have to be done to "Adapt" the Raptor 2s to a ship expecting Raptor 3s if the interfaces of R2 and R3 are not identical. Guy on Twitter/X alleges that private insider sources say that it was the propellant lines A lot of direct and circumstantial evidence that the fuel feed system has a large percentage of new components. Raptor on the other hand, maybe they modified it a bit to adapt to the new fittings (which may or may not exist) (and they could (and IMO they would likely) have modified the vehicle instead of the engines). Apart from that, they are the same Raptors we have seen on previous flights - If they have leaked it wasn't major enough to get a mention in any report, and wasn't major enough to cause anything visually wrong with at a minimum flights 5 and 6. Again, we do not know for sure where the leak was, but there are many reasons why suspicion currently resides with the propellant feed system and not the engines. If it was the engines, then yeah, they've got to fix that. In that case, it is a good thing they're deep into development of Raptor 3 which, among other things, is designed to replace a large number of bolted joints (and therefore possible leak sources) with single parts, internal channels, and welded joints. Also like. This whole time I had assumed you were replying to other comments I had made about Raptor but I double checked after writing the above (though before the proofread and some edits) and you actually replied to my cost-per-flight comment that was unrelated to Raptor that I had posted 1. because I actually encountered someone claiming 389m per flight (though I now must say that I misinterpreted his words, he was stating that cost per kg parity with Falcon was likely to happen but anything beyond that was unpredictable, apologies for the public slander Anthonator00) and 2. in a (vain) attempt to disarm the quite heated political conversation that was going on at the time. While I will give you the benefit of the doubt - It is quite possible that enough of the political stuff got deleted, for you to go - "Steve tried to change the subject away from the leaks!" and tried to get me back on topic - You are not beating the "Tries to shove Raptor reliability conspiracies into every single conversation no matter how related or unrelated it is" allegations. "Hey, what's with all the politics, how about a nice conversation about approximate launch cos-" "HEY what if Raptor is leaking? What if people are talking about it leaking? It leaked before, they know what caused the leaks and they aren't telling us!" Is a little bit of an exaggeration but it adequately summarizes what I feel. If this continues I'm just going to stop replying. Right now I think the value of my analyses to the others in this thread outweighs the pain of feeling like I'm banging my head up against a brick wall every time you take 5 minutes to pose (often flawed) arguments that take 2 hours to deconstruct. But it is getting very close. Don't ask me what the NSF scuttlebutt is. It is right there. One google away. Go look at it yourself.

I'm going to steer clear of the current topic for hopefully obvious reasons (though I do have mixed feelings on it). I had a conversation with someone on Discord today about the sticker price of a Starship launch - As in, you can go to spacex.com and the sticker price for a launch on a reused Falcon 9 is currently 69.75 million dollars. There are extras that can push that higher, of course. But I was wondering what the sticker price for a standard LEO Starship launch on SpaceX's website will end up being when they finally post one (both in the short term and the long term). Specifically for the sake of comparison, a standard fully reusable cargo launch with no extras (refueling flights will probably be less due to no payload processing). Like on one side you've got the people thinking they will actually get to 2-3m. Then on the other side you've got the people that think that the reusable architecture is so complicated that Starship might eventually be able to get below Falcon 9's cost per kilogram (only maybe putting the sticker price below 389m for a 100t capacity Starship in the long term, more if the payload capacity grows). I find both figures insane. My current train of thought is that barring any major departures from the current concept, Starship's sticker price (once published) will never be more than the current Falcon 9 sticker price (69.75m) with it eventually falling to somewhere between 10 and 40 million dollars per flight (though admittedly that is quite a large range). Thoughts?

I will take a moment to acknowledge that there have been a lot of (thus far to my knowledge) unconfirmed reports of debris falling on land. If this is true then this is probably the most consequential incident Starship has had thus far.

If that's the one thing you took away from that post then you might need to read it again. It is not a reasonable position that Raptor is unreliable because on flight 1 none of the 33 Raptors got to the end of their burns, therefore Raptor is at 0/33 and had 33 engine failures. I took the widest possible definition of engine shutdown for the sake of argument and then pared that down to failures that were conclusively or likely the fault of Raptor by removing failures confirmed to be caused by something else. If I remember right I only ended up with a few actual suspected Raptor failures. If you are curious as to how I would rate this flight, to my knowledge, the current indication is that the upper stage engine shutdowns were all related to the fire above the engines (likely caused by leaks in the newly redesigned fuel feed system) because of that compartment exploding/bursting. The booster engine not restarting during the boostback is an open question. I think this is most likely the engine saying "Hey I probably can't restart given these conditions but I don't think I'm broken" and the flight computer decided to play it safe and not send the ignition command. This tracks with it being seen working just fine later. This is hard to classify as to my knowledge this hasn't really happened before, as having a vehicle with enough engines to do this with is a very new thing. However I must steel man this in your favor as we do not have any official indication, putting flight 7 at 58/59 until the time when we receive further indication. (emphasis mine as to what I'm currently responding to) I think you are misunderstanding the short/medium term goals of this program. Starship is not the product of a typical scenario, where a company needs to start flying customer payloads ASAP to start generating profit. They could have focused on delivery of customer payloads immediately. However here is a list of Starship's current launch contracts and launch plans: Confirmed contracts (note that some of the Lunar payloads are expected to rideshare): HLS and all of the test/flight/refueling launches that requires Astrolab's FLEX rover, to be delivered to the Moon, requiring refueling Superbird-9, a geostationary communications satellite to be launched to GTO by Starship, possibly with and possibly without refueling, that is unknown. Scheduled for 2027. Starlab LEO station, no earlier than 2028 Lunar Outpost's Eagle rover, to be delivered to the Moon, requiring refueling Other plans without (public) signed contracts yet: OffWorld's Lunar ISRU demo (to the Moon, needs refueling, though will likely rideshare with something else) JAXA's Lunar Cruiser rover (though does have a statement of intent from NASA specifying delivery to the Moon in 2032 via Starship, needless to say with refueling) Polaris 3 if that is still happening, requires ability to land on Earth VAST Haven-2 core is planned for Starship with no contract yet, this is going to be very late 2020s at best. If Starship does very well in the cost department, some of the other modules could switch from long-fairing Falcon Heavy to Starship. All of the internal Starlink Stuff, does not strictly require reusability but Starlink is banking on cheap launches so if they don't do this reusably it is very bad for Starlink All of the internal Mars stuff, requires refueling and the ability to land on Mars (I am also assuming here that refueling is not economical without reusability) The entirety of Starship's contracted and planned mission set that can be accomplished by an expendable non refuelable variant is... 3 missions. Superbird-9 (assuming expendable Starship can push it to GTO), Starlab (assuming it is selected for CLD), and one (though possibly more) module of Haven-2, assuming it is actually built. And they have somewhere around 2-3 years until they have their first relevant launch contract depending on when in 2027 they want to launch Superbird-9. For the sake of argument, I will point out that Superbird-9 was originally supposed to launch in 2024. No clue if the delay there is because of the satellite or because of the launch vehicle. But for the sake of Steel-Manning this, I'll assume Superbird-9 has been sitting finished in a Hangar since December 2023 and 100% of the blame falls on SpaceX. In that case, SpaceX missed out on a grand total of 1 commercial launch by not choosing to go expendable at first. To get to the point, SpaceX effectively has 2-3 years with little obligation besides getting re-entry, reuse, and refueling ready for all of its other launch contracts. And as such that is what they are doing. A rapidly reusable, cheap, and reliable heat shield has never been built before. From what I can tell, that is the long pole that is currently driving the schedule. It is a prerequisite for: Cost effective refueling at all High cadence refueling (generally required for boiloff sensitive missions, or if you want to do more than 1 moon mission per year) And therefore it is also a prerequisite for most if not all missions that require refueling, which is the majority of their current contract roster. Thus it makes complete sense why SpaceX has been focused on proving reusability/heat shield functionality while neglecting payload delivery. They do not want to build a payload delivery system and then retrofit in reusability. They want to build a reusable system and then they will use it to carry payloads. In that case, 10-12 and more flights to prove high payload delivery is completely acceptable, as these early flights are not looking to prove that, that will come later. Considering it took Falcon 9 until flight 33 to do full Merlin reuse, doing it in 15 would be amazing. Though let's be generous, they didn't even start attempting supersonic retropropulsion until flight 6, so 28 flights. I'm currently about 50/50 on whether they will wait until booster v2 to reuse a booster or if they are going to go full send and reuse the booster that was just caught. So there is a world in which this is <10. This I am less sure of. This demo must absolutely happen this year to protect against a stupid amount of delays in every other planned mission. However (and I could be wrong or maybe this person misspoke or maybe the person I got this info from is wrong), I think someone at NASA recently said that Ship V3 is going to be required for the refueling demo. If this is accurate, refueling could be a ways away, as it would shift pretty much all of V2 towards early catch/reuse/heat shield testing. This is one thing I am actually somewhat concerned about. Of the western(-aligned) rockets (as I'm unlikely to find anything about the Chinese rockets) to debut since 2020: Ariane 6 did a full duration static fire of the core but without the boosters, a configuration that results in a thrust somewhere near 10% of liftoff thrust in the 4 booster configuration, and is such, not a full up, full thrust, full duration test. Points for at least doing it with boosters, upper stage, and fairings attached though. I cannot find good sources but I think that "proper" sort of testing might have been done for the second stage. H-3 did not do full up, full thrust, full duration testing as far as I can tell. At best the core stage was fired for ~25 seconds without the boosters, though I cannot find any information about the upper stage. SLS did do a full duration test of the core stage, but without the boosters, and without anything above the core attached (if my memory is correct). This is about 25% of the liftoff thrust of SLS. Unsure if the ICPS had been static fired, but given that it has a lot of flight heritage there wouldn't have to be any SLS specific static fires. Vega C might count as its first stage as test fired, though horizontally, and not with the rest of the stages attached. But I'll give it a point. Firefly Alpha did at least a 42 second static fire of its first stage, If it did a full duration firing, it went under my radar. Starship does not do full duration static fires. New Glenn did a 24 second static fire. Vulcan to my knowledge never completed a full duration static fire of the core stage, only short duration static fires, and with no boosters. Might have missed a few and I definitely got lazy on checking upper stage tests. But it does not appear that this is the industry standard any more. When all up stage testing was done, it was typically done on sustainer type rockets, with a small to moderate percentage of the total liftoff thrust active. The rocket that gets the closest to the type of testing you desire appears to be Ariane 6. I don't see you dragging Vulcan or New Glenn through the mud for only doing partial duration partial thrust static fires on the launch pad like Starship does. There's more but I've spent enough time on this for today.

Sure, you can hurl a decent amount of mass to Mars with an expendable variant. Maybe up to 100 tons in a single lanuch if fairly optimistic numbers are used. However (assuming the goal is humans to mars) then you need a Mars lander, which needs a heat shield, RCS, engines, fuel tanks, guidance systems, power systems... Possibly aero surfaces too. Then you'll need a habitat for the crew, requiring a large pressurized volume, with enough space and power for life support systems, airlocks, elevators, and cargo... Huh. That sounds an awful lot like what you would do for a reusable LEO system. So the question now is "Why don't they bother making a custom lander for all of that stuff and skip it for LEO?" And the answer is because they are aiming for an out of the park home run, however wise or unwise that is. They don't want to get to Mars once, they want to make it affordable, pretty much necessitating reusability and orbital refilling and commonality between the Mars vehicle and their other vehicles. If the goal is payload to Mars per launch, yes, an expendable upper stage on modern-ish Super Heavy is absolutely the play, likely with a further third stage on top of that. The targets they appear to be aiming for are payload to Mars per dollar, and per-pad/booster/ship throughput. Now as for the Moon. You run into a lot of the same problems as Mars - You can get ~100 tons to TLI depending on what numbers you assume. Then you need to at that point have a vehicle with engines, fuel tanks, navigation, power... Though sticking with Starship is less solid than it is for the Mars example. Starship is very much not a Lunar optimized architecture and it shows. It was picked as it reused a lot of effort from internal SpaceX projects they were self funding, and it could therefore be shoehorned into the role of a Moon lander for a lower cost than clean sheet designs. I wonder if SpaceX will ever consider a ground up Lunar optimized architecture. It would likely look quite different from the existing vehicle.

Interesting tangent: Starship seemed to carry on just fine with this engine configuration for several seconds (Still accelerating enough to probably not be spinning) before ultimately failing. This surprised me as I was under the impression that Starship (the upper stage) had minimal to no engine out capability. I don't have perfect numbers, but I did shove my numbers into a spreadsheet and I came up with the following: Assuming my numbers are right, immediately throttling the two Raptor vacuum engines down to minimum and gimbaling to the limit of 10 degrees might be enough to cancel out the torque from the uneven engine distributions in this vehicle configuration. On the surface the math says if the CoM is more than ~21.9m from the base of the vehicle it should be stable, but the propellant will slosh towards the side of the vehicle with the engines in this case, which causes all three engines to produce less "vertical torque" and would beneficially reduce this number, by how much I am unsure. Admittedly my source is just some guy on Discord, but I'm told that Raptor can normally gimbal to 15 degrees, but that the current engine shielding limits that to 10 or 11 degrees. Interestingly, for future ships using Raptor 3, the full 15 degrees would be available and this puts the minimum CoM height at only about 15.8m, though future versions of the ship may have to limit their gimbals to avoid hitting the vacuum engine bells. I don't know if the resulting thrust (of roughly 30% of normal thrust) (though if the CoM is higher than the minimum you can throttle the Vactors up more than 40%) would be enough to get into orbit for any situation aside from very late in the upper stage burn, but I find it very interesting that Starship can (at least theoretically) survive under some conditions with only 3 engines running, all on the same side of the vehicle, only one of which can gimbal. Assuming I did my math right, of course, it has been a while since I took statics.

Went to sleep before the stage 2 burn - Congratulations to Blue Orign on this success! I was only a little bit sad when they showed the Kent team and I was like "If I had a slightly better interview I could have been in that crowd"

Do they have an atmospheric perigee?

Not looking good on the booster side of things - Telemetry frozen. I think it should have landed by now.

I cannot confirm or deny this, but I have also heard that it could be flight 4 due to the internal arrangement, but I have also heard people say that the hot spots match up with the flaps removed from flight 6. I have not double checked either of these claims, so who knows. Also while that is certainly not acceptable for an operational vehicle, we don't know the exposure settings of the camera, and some cameras pick up a little infrared as they are imperfect - So it might not be quite as bad as the picture suggests.

Most people here use imgur.

I see a range of 500W-3000W for a vacuum cleaner, I will assume a 2000W vacuum. That would be about 691 megajoules of energy. This is equivalent to about 5.7 gallons of gasoline, or around 2500 F1 hand grenades (I couldn't find good numbers for more modern hand grenades - Maybe like 500-1000?), or the amount of power an average American household uses in a week, or 165 kilograms of TNT, or about 700 twinkies, or about 2-3 electric vehicle battery packs. Those things all have different effects, so it would largely depend on the rate of energy release from these hypothetical batteries. Intuitively I would expect it to be similar to an electric vehicle fire but faster, but the battery technology we are talking about would be so significantly different from anything we have now that I have no idea how it would behave in a failure scenario.

A shame. My sleep schedule was starting to recover. Another delay