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SpaceX successfully launches Superheavy and Starship

Superheavy & Starship, on their way
Note how all 33 Superheavy engines are firing.

SpaceX this morning successfully launched its Superheavy/Starship heavy lift rocket into its test orbit.

The test flight achieved far more than the first test in April. First, during the entire flight of Superheavy all 33 Raptor-2 engines fired normally. None cut out prematurely. Then at very risky hot fire stage separation — where the second stage (Starship) ignited prior to separation from Superheavy — the correct number of engines shut down, Starship’s engines fired, and Superheavy successfully separated and began its maneuvers for a soft splashdown in the Gulf of Mexico.

At that point mission controllers issued the self-destruct command to destroy Superheavy. Though it appeared that the stage was struggling to flip for its controlled return to Earth, it is also very likely that mission controllers wanted to test that flight termination system after its not perfect performance on the first test flight. Then, the self-destruct command did not activate the instant the command was given, being delayed by about 40 seconds. This time it appeared it worked as planned.

Starship statistics at self-destruct

Meanwhile Starship continued what appeared to be a perfect flight, until just prior to when its engines were suppose to shut down in orbit. For reasons not yet explained, at T+8:20 minutes — 13 seconds before that planned engine shut down — mission controllers or the spacecraft itself issued the self-destruct command. The image to the right shows the situation at that self-destruct. Starship was at 148 kilometers altitude traveling at 24124 kilometers per hour, very close to its intended orbit.

It is very possible this was also a test of Starship’s self-destruct system, as it would be a very bad thing to have Starship in its low orbit but out-of-control. Such a situation would mean it could crash down in inhabited areas.

Based on what appears to have been a perfect flight, with all engines and operations working as planned until self-destruct, there should be no reason for any long delays before the third Superheavy/Starship test flight. Prototypes are built and ready to go. All SpaceX would need to do would be to carefully review the data from today, institute some upgrades, and fly. If it was up this company and how it normally functions, the next flight would probably take place about a month from now, before the end of the year. SpaceX needs at least a dozen test flights to get this rocket operational. To meet the schedule of both the company and NASA, those flights should happen quickly, all in 2024.

We shall see. I expect the FAA and Fish & Wildlife to demand a more thorough investigation, which will delay the next flight into 2024, likely until the February to April timeframe.

As always, I hope this pessimistic prediction will be wrong. The lack of any serious anomalies during this test will make it more difficult for government paper-pushers to justify any long investigation.

One final note: This rocket was built entirely from private funds. Though SpaceX has a contract with NASA for Starship as a manned lunar lander, SpaceX has spent almost none of that money because its focus is getting the rocket launched, not designed to land on the Moon.

Thus, a rocket more powerful than the Saturn-5 but designed from the get-go to be reuseable is being built by private American citizens, independent of the government. If that isn’t a demonstration of the power of freedom, I don’t know what is.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.

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  • Frank

    Super heavy looks strong and fit.

  • John

    I would like the comment that THAT WAS AWESOME!

    They’ll get there. If the tyrants allow them.

  • Steve Richter

    How is it that Starship is intended to land near Hawaii when it launches east over the Gulf?

  • Steve Richter: Starship is being placed essentially in orbit. It circles the globe eastward, so that it can be de-orbited to land north of Hawaii in the Pacific.

  • Questioner

    Mr. Zimmerman, I must correct you: It was a great test flight: the first stage, stage separation and Starship ignition worked very well, but Starship was destroyed about 30 seconds before shutdown or before orbital injection by the FTS. According to rumors, this could be due to a slightly underperforming propulsion system. I assume that Super Heavy did not reach the intended return trajectory and was therefore destroyed.

  • Jeff Wright

    It bested N-1 certainly.

    The SuperHeavy explosion looked like the Crab Nebula.

    Full stack made it to space.

    I still support SLD–100% successful

  • Cluebat

    @Steve Richter

    They are actually planning to fly under the turtle and around.

    Perhaps they will discover the gender.

  • John hare

    What was the IIP at second stage FTS?

  • Sayomara

    Bob, do you know why they didn’t have an cameras on the rocket. I seem to remember that has been something we have seen on other test flights.

  • From a picture over at NASA Space Flight on YouTube, there were quite a few TPS tiles missing from Starship. I wonder if that might be a reason that SpaceX decided to test the FTS on Starship 25 rather than have it destruct on reentry? I guess we will hear in the next few days if that was the case. It would help make the FAA happy that the new FTS is workable.

  • V-Man

    Right after separation you can see that some engines didn’t relight on the booster. If it was struggling to keep under control, a termination was safer (plus bonus FTS test).

    Not sure what happened on Starship but several commentators online pointed out that the trajectory wasn’t quite where it needed to be.

    We’ll get some explanations (and hopefully onboard footage) in the next few days.

  • Edward

    Robert wrote: “Meanwhile Starship continued what appeared to be a perfect flight, until just prior to when its engines were suppose to shut down in orbit. For reasons not yet explained, at T+8:20 minutes — 13 seconds before that planned engine shut down — mission controllers or the spacecraft itself issued the self-destruct command.

    I saw things a little differently. Even before this point, changes occurred in the exhaust trail, looking a little like it had just entered sunshine, but since it launched in daylight, that was not the explanation. I suspect Starship had some engine trouble quite a while before loss of signal.

    Super Heavy looked good, but I had expected separation a little sooner after the reduction in the number of engines. In addition, I do not understand the asymmetrical engines during boost back.

    We will have to see what SpaceX will tell us about their results.
    Onboard cameras take up a lot of bandwidth (transmission capacity) that can be put to better use with engineering telemetry on a development flight. Exterior views tend to be less useful for engineering but fantastic for public relations.

    There may have been cameras on board, such as in the engine compartments, but SpaceX may desire to keep that information proprietary for now.

  • Ray Van Dune

    Bob, you imply that SpaceX may have deliberately initiated the self-destruction of both stages of the Starship, as a way of demonstrating to the FAA that the improved FTS was highly effective. This would make some sense, but I have heard several times that there exists no “big red button” that a human controller can push to fire the FTS: that it is completely autonomous!

    That seems strange to me, but I have heard it many times.

  • Edward

    Come to think of it, the announcers did not mention a test of the flight termination system (FTS) as part of this test, but they did mention a soft splashdown of Super Heavy in the Gulf of Mexico and Starship coming down in the Pacific as bonuses to the test.

    In addition, SpaceX had performed at least one ground test of the modified FTS, and this seemed to have satisfied the FAA. I doubt that these were intentional, even to demonstrate their correct operation for the FAA and themselves.

    I am also with Ray Van Dune on this. For a development test, it seems unwise to forgo a FTS button for the range safety officer. It may even be unwise for an operational mission.

    Overall, the test accomplished more than just the goal stated by the announcers, making this another extremely successful test, including what seems to be many additional lessons learned.

    If I recall correctly, these were Raptor 2 engines, giving them some flight time and experience. I do not know whether the next flight will also be Raptor 2 or if the Raptor 3 will be ready for that flight.

  • Steve Richter

    CNN had live coverage. I saw nothing on Fox News. But it was on the Fox weather channel. The republican party should be touting this as private industry achieving something great for the country. And great chance to point out to the public that the democrat party is doing all it can delay and harass SpaceX.

    WSJ headline: “SpaceX’s Second Starship Test Flight Ends in Another Explosion”
    NY Times is more accurate: “Elon Musk’s Giant Moon and Mars Rocket Makes Progress in 2nd Flight”

  • MDN

    My observations:

    1. Raptors work! During this flight we witnessed just shy of 2 HOURS of Raptor engines operating nominally under full thrust. That is likely more than the BE4 has seen during its entire development life to date.

    2. Super Heavy is already as successful a rocket as SLS ever will be. The leap will come when they can stick the landings of Super Heavy and then Starship itself.

    3. The Hot Staging plan worked! There may well have been damage to stage 1 which required flight termination, but that is a refinement they will correct from the data they collect.

    4. Starship ascent worked! In this flight SpaceX already likely set the record for mass to orbit for a single launch.

    5. Electric gimbaling worked! This was another major change from the previous vehicle and should not be overlooked.

    6. Stage 0 looked to weather the launch largely intact with essentially no impact on the local wetlands. Follow up aerial surveys we will see today from the Starship following collective will tell the tale in better detail, and this is where the FWS will focus their post launch assessment. But it seems unlikely there is any big issue as we had after IFT 1 to justify the imposition of new and really significant changes.

    7.. I am sure there is extensive on-board video documentation that SpaceX will be reviewing if telemetry did not fail. Remember, this was part of the Fix List required after IFT 1. I am not surprised this was not shared live as it well could include information SpaceX deems proprietary but I expect they will release plenty of snippets to satisfy our curiosity in the days ahead.

    8. As far as what’s next that will depend upon data analysis. If the hot staging inter-ring needs significant re-architecting (perhaps stretching out to several meters in length instead of just 1 for instance), then we’re talking about several months probably at least as that involves a ground test cycle as well as moving the Stage 0 ship quick disconnect again. If the changes identified are more bounded then it may well be just a month or so before we see IFT 3.

    9. SpaceX got very VERY close to their real primary objective for this program. As Elon has said many times the initial focus for now is on getting TO orbit. Everything after that is where the leap in technology comes in, but once they get to this point it’s totally OK if that takes 10 or 20 more test flights to do. The reason is because even though these will cost a lot of money they will still be placing LOTS of FULL SIZE/FULL CAPABILITY Starlink V2 satellites in orbit as they go getting that program literally off the ground as too. And all the data they gather from successive flights will allow them to optimize out lots of excess from the current (over designed) airframe maximizing their ultimate mass to orbit efficiency. Just as the best part is no part, the cheapest mass to orbit is any mass that you don’t really have to take.

    Kudos to all at SpaceX, IFT 2 was a tremendous success!

  • Ray Van Dune

    I said the other day that I would be counting the running engines on the climb-out, and I was. I saw all 33, followed by all 6 on the ship stage. To have 100% of 39 engines function correctly on only the second test flight is a remarkable achievement.

    Ps. Those were probably the largest “mach diamonds” ever created!

  • Gealon


    Let’s hope we get a third launch before too long.

  • Calvin Dodge

    I believe the self-destruct for IFT #1 took place at the right time. The 40 second delay was due to the charges being inadequate. They blew holes in the tanks, but the holes were small enough that boiloff kept internal pressures high enough to maintain rigidity.

  • All: I must add a detail that is NOT in my story, but should have been. I did not add this launch to my launch race totals, because of the use of the flight termination system on Starship prior to engine shutdown.

    When a Starship finally reaches its coast phase, in orbit, I will then add that Superheavy/Starship launch to those totals. Even though Starship will not complete a full orbit before coming down in Hawaii, it will be in orbit, though a very low one that is unstable and will decay relatively quickly regardless.

    Nonetheless, this test launch was a success, because Starship clear could have reached its coast phase.

  • Richard M


    Yeah, I think Scott Manley’s analysis makes sense, now that we see the footage more closely. The center engines start shutting down. Scott’s speculation of a fluid hammer dynamic at work at least sounds plausible, Either way, it is now evident that the Super Heavy suffered a serious failure during the flip maneuver, and that is why the FTS kicked in.

    Still, the Super Heavy got the primary job done: It got the Starship to stage separation, and handled the hot firing maneuver perfectly, apparently. Every single one of those 33 Raptors worked from start to end of the ascent. This is enormous progress.

    Hello Bob,

    “At that point mission controllers issued the self-destruct command to destroy Superheavy.”

    Just one niggle: the Flight Termination Systems are automated. While ground controllers retain, as I understand it, a manual capability to trigger them, these terminations would have been triggered by the FTS computers, once the sensor readings reached pre-determined parameters. Watching Manley’s brief breakdown, it is easier to see why the Super Heavy FTS triggered; what is less clear is why the Starship FTS did so.

    And so close to the end of the burn, too! I agree with you that this is tremendous progress. SpaceX and NASA should be quite pleased with what we saw today. And given that the launch pad appears to have sustained no significant damage (or send concrete storms into the swamp), I have to think it will not take long to get license for the next attempt. Fingers crossed.

  • David Eastman

    Awesome test! I woke up late, and made sure to go watch the stream without checking anything that might spoil it for me. I was so happy to see that monster lift off with all 33 raptors burning, it was quite obvious that it was lifting off a lot faster than IFT-1.

    It looks like FWS should be very minimally involved in the next license, just a quick check of data from the deluge system and some checking for any dead or disrupted animal life, and they sign off that the changes from IFT-1 met their criteria. This SHOULD take a few weeks at most and not be the long pole. We’ll see.

    FAA will likely consider this a fully successful test from their criteria, but will want to review whatever changes SpaceX implements. Call that a month of work on their end, starting after SpaceX gives them the data they need.

    If SpaceX choses to launch the next one as-is, I consider it possible, but highly unlikely, that they’ll get the license before EoY. That would be quick turn-around for the FAA and FWS, and it’s getting into holiday time. If SpaceX is going to make any changes, February seems like the good bet if you trust the government agencies to do their jobs on time. March or April, as Bob says, otherwise.

  • GoesTo11

    I’m gonna chuckle when Elon puts a woman on the Moon before NASA.

    Assuming they’ll allow it.

  • Ray Van Dune

    I think the biggest unknowns are the FTS activations, and hopefully SpaceX has adequate telemetry to allow them to design and implement the required change(s).

    It may be that the thrust from the firing of the ship engines was too strong, and/or the sustaining thrust from the booster was too weak, to keep the booster propellants “settled”. Once flow was interrupted and the engines stopped, I don’t think there was a mechanism to re-settle the propellants and restart the engines. This might be a bigger problem than it first appears.

    As for the ship FTS activation… I hope they got enough data to understand what happened!

  • Questioner


    I find it very strange, to say the least, that a NASA official – in response to this test flight – would emphasize the sole goal of putting a woman on the Moon. Has the US completely fallen into feminist madness (another communist thing)?

  • David Eastman

    One thing that hasn’t gotten much attention is how well their stage zero mechanisms have worked for all the pre-flight work. They stacked and de-stacked this rocket 8 times, I believe, and they’ve gotten it down to an amazingly efficient process. They discovered the need to replace a major part on Thursday, de-stacked, replaced that part, re-stacked, and launched, with a slip of one day. I don’t think even their Falcon 9 handling systems at the cape could do that quick a turnaround on something that required de-stacking the upper stage and payload, and no other launch provider could even come close.

  • David Eastman: I mentioned this fact during my Friday Batchelor appearance. That SpaceX has designed this rocket to be so easily accessible and repairable suggests its final testing will go far quicker than anyone predicts. They have the ability to institute upgrades and repairs on a dime’s notice.

  • Ray Van Dune

    Mr. Eastman, your observations on Stage zero are very apropos, thank you for drawing attention to this.

    But one component of Stage zero worries me, and it is the Hot Staging Ring. Yes, technically it is part of Stage one, but it was involved in many maintenance activities of Stage zero due to its unique physical location – it has to be removed to access so many components, like the last instance, access to the grid fin motors.

    I have wracked my brain but cannot imagine an alternate mechanism for access than disassembly, what would not involve reduced structural integrity and/or increased weight!

    Ps. A related question: why did SpaceX feel the need to replace three of the four grid fin motors? If there was a flaw that pervasive, why not replace them all? Perhaps they used all the replacements they had on hand?!

  • Deplorable Dave Parsons

    It was beautiful how all those booster engines burned perfectly, but I don’t understand how they think they’re supposed to relight after flipping.
    Try driving your car until the tank has only vapors left in it. Then flip the car upside down into a ditch. Then try to start the engine. Not gunna happen.

  • Ray Van Dune

    Dave Parsons, I think the theory is by keeping some booster engines running, they can maintain some “g” while the ship pulls away. Then the booster flips but since it is still thrusting it actually does a loop, maintaining some “down” g. But if the engines quit producing thrust, you’re hosed!

    I always heard that the advantage of hot staging was to never quit accelerating the ship along the trajectory, but it also means the booster has to never quit accelerating too, or the engines lose their prime!

  • pzatchok

    They could use baffle system ti help keep some fuel to the bottom of the tanks,

    That and a good removal system to keep air lock out of the engines.

  • Michael

    The fuel bottoming issue may be the cause but I would have thought the would have has a handle on this issue as they perform the same maneuver whenever a Falcon 9 returns to launch site.

  • Ray Van Dune

    Michael, I had the same thought, but I think the F9 has cold-gas thrusters to orient the booster and provide ullage thrust to settle the propellant until the grid fins are effective.

    Another difference is that F9s often do not do boost-back burns, but simply rely on the fact that the booster is at much lower than orbital velocity, and will eventually re-enter the atmosphere and the grid fins will have effect, settling the propellants quite nicely!

    This scenario assumes a drone ship landing. Superheavy is assumed to do an RTLS to be caught., but it does not have the cold-gas thrusters required for it as F9 does! This is how I see it anyway.

  • Edward

    Richard M wrote: “the Flight Termination Systems are automated. While ground controllers retain, as I understand it, a manual capability to trigger them …

    Several others noted that FTS is automated, implying a lack of ground termination capability.

    This has been standard for many decades. Specific conditions trigger onboard Flight Termination hardware, and if the flight safety officer believes he should ensure its destruction, he has his own button. If the Booster did not believe that it had become a hazard, then it may have followed Asimov’s third law of robotics and preserved itself only to have the range safety officer invoke the second law in order to assure the first law was fulfilled.
    David Eastman wrote: “I don’t think even their Falcon 9 handling systems at the cape could do that quick a turnaround on something that required de-stacking the upper stage and payload, and no other launch provider could even come close.

    Considering that even Falcon has to go back to the assembly building, this is unlikely to be a quick process, and restocking may be even slower for other launch providers’ vehicles. Mechazilla may have seemed impractical or overkill in the early days, but it paid off yesterday. Even if they cannot catch Super Heavy or Starship, it seems to be an excellent way to stack the rocket.
    Ray Van Dune wrote: “But one component of Stage zero worries me, and it is the Hot Staging Ring. Yes, technically it is part of Stage one, but it was involved in many maintenance activities of Stage zero due to its unique physical location – it has to be removed to access so many components, like the last instance, access to the grid fin motors.

    This Hot Staging Ring is a retro-fit. SpaceX is likely to optimize future rings for ease of maintenance, among other things, most likely incorporating them into the booster stage rather that as a separate item.

    but it also means the booster has to never quit accelerating too, or the engines lose their prime!

    A generic booster only has to continue acceleration until separation. A reusable booster needs to keep firing until the boost back burn ends (if it boosts back to land). As with the Falcons, there is some amount of force in the upper atmosphere to provide settling in the tanks just before the reentry burn.

    Ray Van Dune,
    You asked: “A related question: why did SpaceX feel the need to replace three of the four grid fin motors? If there was a flaw that pervasive, why not replace them all? Perhaps they used all the replacements they had on hand?!

    In my experience, engineers replace only the hardware that is questionable. The first grid fin motor may have had a real problem, but the other two may only have had indications of minor problems, making them questionable. The fourth may not have been questionable at all. While they were there, they chose to put in three good ones but also chose to not replace another good one with one off the shelf. Engineers expect that the ones on the shelf are good but also expected the ones on the test article were good, too, but they weren’t. If it ain’t questionable, don’t even think about replacing it
    Deplorable Dave Parsons wrote: “I don’t understand how they think they’re supposed to relight after flipping.

    They kept three engines lit through separation and the flip in order to keep a positive acceleration (gravity) on the tanks. This should provide some amount of settling through the flip. For the boost back burn and the landing burn, they will need quite a bit of fuel, so there may not be much worry about sloshing and bubbles. Micheal is right. SpaceX has practical experience with Falcon, so the company is learning lessons about the larger scale.

    Modeling has its uses, but as Robert likes to remind us, it is not to be confused for reality. pzatchok‘s baffle idea may be good, or it may already be incorporated.

    On the other hand, these tests are intended to confirm the theories and mathematics. It also helps them find the flaws in these theories and mathematics, and it looks like they may have found a few.

  • wayne

    here we go….
    tangentially related….

    Saturn 1B AS-203 S-IVB Hydrogen Tank Interior

  • Max

    Upon review I’d like to confirm Edwards observations.

    After separation it appears the booster turned too quickly causing sloshing of propellent and flame out on half of the engines. (Picture a nearly empty water truck swerving to avoid an object, being nearly empty the water truck is more maneuverable but the remaining water flows to the side causing instability overturning the water truck)
    There is a jetting of vapor visible as well as the oxygen levels in the tank drop significantly just before self-destruct.
    (Incorrect fluid mixture and auto compensation may have led to an explosion or simple failure/ emergency shut off fault)

    As for starship, as Edward noted the sudden appearance of gases is evidence of a failure in progress. Until this moment the speed of the craft was consistent, then suddenly the speed increased considerably but did not gain in any altitude! At the same time, the oxygen tank was being drained at twice the normal rate. (visible tracking of starship engines ceased leading me to believe that the craft had turned?)
    This anomaly, running out of oxygen, was probably what led to the self-destruct… Fortunately before reaching orbit were Elon musk would hear no end of grief for space debris.

    The other failure in a otherwise beautiful lift off, was placing a large man with an even larger cowboy hat directly in front of the control room camera.

  • Ray Van Dune

    Just spent a couple hours looking at videos of IFT-2, particularly the post-separation flight of Superheavy.

    It appears the SH did a rather beautiful loop after the hot staging, as required, and then ran into trouble. At that point, there are numerous jets from the rear end visible. These appear to be at a very high angle of deflection, beyond the limits of the vectoring sea level Raptors.

    What are they?

  • Jeff Wright

    The best part of it is that supersonic debris may have woken up Branson and the old money in the Caribbean :O

    One year ago…a real success

  • wayne

    Interesting Stuff, from all. (This is more fun than politics, eh what?!)

    Hat Tip to whomever suggested the Scott Manley clip, very good close-ups, and he starts to approach Zapruder level film analysis.

    A more general Question for the engineers in the audience:

    Given our current technology, how important is it, to physically examine Stuff after it blows up Vs. instrumenting everything to death and looking at the telemetry later?

  • Michael

    Ray Van Dune: point about the F9 cold gas thrusters is well taken but if I remember correctly the booster has those “cow bell” vents which I thought use a tank’s ullage gas to act as RCS thrusters. In my mind’s eye I can see the vents flipping the booster and applying the force to settle the fuel. Per the engine telemetry readout it basically showed the engines on the starboard side as “on” and the engine on the port side as “off” (generally). Perhaps they were on the right track but the timing of the vent combined the larger size of the vehicle lead to a less than even distribution of propellant which in turn lead to fuel starved engines and the uneven thrusting hence the FTS.

    Oh well. It an interesting point and I know those guys are fifty smarter than me an will figure it out and it won’t happen again.

  • Terry

    The guy with the large cowboy hat appears to be Musk’s younger brother Kimbal Musk.

  • Edward

    wayne asked: “Given our current technology, how important is it, to physically examine Stuff after it blows up Vs. instrumenting everything to death and looking at the telemetry later?

    Don’t you hate when someone answers a question with a question?

    What did SpaceX do with the debris from its bellyflop tests, two and a half years ago?

    However, when the debris falls into the ocean, across hundreds of square miles, you probably aren’t going to get a good look at the Stuff after it blows up, so instrument the hell out of your test rocket and hope you put the right sensors in the right spots.

  • Questioner

    Jeff Wright:

    Thanks for the link.

    While sitting in Florida, this amateur astronomer was able to detect Starship’s anomoly (LOX spill?) about 7 minutes into flight and the subsequent FTS explosion at 8 minutes and 9 seconds.

    His video shows that the upper part of the spacecraft was one piece even after FS activation. Watch at 41 minute in his presentation. Well done.

  • GoesTo11


    Well, yes.

    I don’t wish Artemis any ill operational will, but the whole thing strikes me as 2023 America: A $100+ billion exercise in political pork branded with a Barbie objective.

    I kid, but let’s not let it distract us from what actual pioneers accomplished with this feat.

  • Ray Van Dune

    It occurs to me that a hot staging ring with an asymmetrical dome and offset vents could provide lots of upward rotation to the booster at staging… AND might allow opportunities to access the interstage area without removal of the ring!! The “top” side of the ring (as in flight) might be almost completely solid, allowing an access panel that would not compromise the structure. Hard to visualize.

  • Steve Richter

    Will Starship and the booster ever be safe for humans? It has super cooled fuel that has to be pumped in large quantities to the combustion chamber. Interruptions to the fuel flow or liquids even momentarily boiling off cause engine cutoff or rapid disassembly.

    How do these liquid fuels work in space? I assume Starship will coast to the moon. Is effort needed to keep the fuel chilled the entire way? Once the engines fire to slow Starship down to orbit the moon is an explosion possible? Does the vacuum of space make liquid fuel more manageable?

  • Am I correct that that two pulses in the Starship plume after 7+00 were the suspected O2 leak? The third one was the destruct.

    Note that the nearly once around orbit and landing site are similar to that of the Shuttle ET following Challenger, which reentered somewhere E of Hawaii. Cheers –

  • Questioner


    Yes, a large LOX leak (starting at minute 7) was assumed to be the likely cause yesterday by Scott Manley and others, among others.

  • wayne

    Steve Richter–
    It is my understand, it is very Cold, in Spaceee.

    ->some brief historic clips of interest to your pondering.

    Saturn 1 (SA-5)
    Camera Inside Kerosene Tank

    SpaceX CRS-5 Launch (2015)
    Interior LOX tank camera

    SpaceX CRS-4 Launch – (2014)
    Fuel Slosh, internal tank camera (5G to 0G)

  • Ray Van Dune

    In rereading my middle-of-the-night comment on the hot-staging ring, I realize it might not be sufficiently clear.

    So, let me suggest a physical model for the existing design that we can use for discussion purposes. It is basically a standard-sized booster ring, with two differences:
    1. It has a “bottom” that is relatively dome-shaped, and
    2. It has a series of vents around its periphery.

    This design has a serious operational drawback. Mounted on the top of the booster prior to launch, its bottom dome covers and protects the equipment located in the interstage area, for example the grid-fin motors, as we have seen. This means it must be removed prior to any work in the interstage, and for it to be removed, the ship must ALSO be removed! This is obviously a big deal!

    Now imagine we conceptually modify the hot-stage ring design. We TILT the dome, so that on one side it is still at the bottom of the ring, below the vents., but at the opposite side it aligns more with the TOP of the ring, with no vents below it. Instead of being a somewhat consistent height, the vents start out at the current size, but get smaller as we go around the ring, at some point disappearing altogether.

    What does this accomplish?
    1. There is now a solid ring wall beneath the high end of the tilted dome! This could provide space for a removable hatch, such as found elsewhere on the vehicle! Now the interstage area can be accessed when the rocket is on the pad… no need to remove the ring, or the ship!
    2. When staging occurs in flight, the tilted ring also provides a component of force perpendicular to the direction of flight, and properly oriented, it could substantially assist in the booster backflip maneuver, reducing the need for the use of other systems!

    This is merely a concept, and the actual design might well prove infeasible. It might also be a major operational improvement both on the pad and in flight!

  • Doubting Thomas

    Steve Richter asked: “Will Starship and the booster ever be safe for humans? It has super cooled fuel that has to be pumped in large quantities to the combustion chamber. Interruptions to the fuel flow or liquids even momentarily boiling off cause engine cutoff or rapid disassembly.”

    Steve: Falcon 9 uses supercooled LOX and is man rated for Dragon. I was amazed when NASA allowed astronauts to be aboard during fueling. I grant you that Starship system uses TWO supercooled liquids, LOX and Liq. Methane so perhaps more complex. We shall see.

    Ray Van Dune – Your suggestions for modification to Hot Staging Ring – let us hope that Elon and his team read this website. After all, Tim Dodd suggested something to Elon which was the basis for making a (minor) but helpful change to the booster.

    People have also pointed out that should SpaceX choose to do it, they could continue to make progress with the Ship even at the price of lost Boosters as they continue to learn, much the way Falcon 9 recovery progressed until figured out. It is amazing in how short (compared to the 70+ years of expendable booster spaceflight) a time first stage recovery seems like a necessary basic step. SpaceX could survive for a time (and the moon and Mars Program could make progress) even with Boosters being expended.

  • Steve Richter

    video of Starship shot from the Florida Keys

    RGV Aerial Photography report on how the launch site fared:

  • pzatchok

    I wonder if they could possibly use self contained draco thrusters for after stage separation orientation?

    They only have to be on the bottom of the rocket and only have to orient it to an engine forward orientation then the main engines could take over.

    The second stage thrust is used to flip or push the top off to the side. Thrust deflectors.

    They could get rid of the whole cold thrust idea and all its equipment.

    They could even add another 4 grid fines top the top side just to flip out and slow the first stage down. They could retract, flip down, after their use is over.

  • Doubting Thomas

    The FAA says in a tweet: “A ***mishap*** occurred during the Starship OFT-2 launch from Boca Chica Texas on Nov 18…..No injuries or public property damage has been reported.”

    This is why with the FAA in charge we will advance at a snails pace. It was not a mishap, it was a test which advanced system knowledge. As long as no injuries or damage to public property occurred then it was NOT a “mishap”.

    We would still be flying tens of flights per year of Wright Model C’s if the FAA had been in charge in starting in 1903.

  • Edward

    Doubting Thomas is correct. The FAA does not recognize development testing, even when it over-regulates it. There were similar mishaps with the bellyflop tests, yet the next test in the series happened within a couple of months.

    The only real safety problem on the first Integrated Flight Test was the Flight Termination System, and once that was demonstrated to be solved, the license should have been issued no later than it took for the ink to dry on the signature lines. All the rest is bogus regulation. Worrying that a swamp might get wet, no less.
    Steve Richter asked several questions:
    Will Starship and the booster ever be safe for humans? It has super cooled fuel that has to be pumped in large quantities to the combustion chamber. Interruptions to the fuel flow or liquids even momentarily boiling off cause engine cutoff or rapid disassembly.

    Artemis, the Saturn V upper stages, the Space Shuttle, and several other rockets use a colder fuel than liquid methane: liquid hydrogen.

    How do these liquid fuels work in space?

    Generally, before an engine start, there is a period of low acceleration that is used to settle the propellants to the feed tubes. An advantage of hot staging is that this period of time is not needed to ignite the Starship stage during launch.

    wayne (November 19, 2023 at 10:09 am) linked to some videos that show the interior of propellant tanks, and there are a few notations that tell us what is happening and what needs to happen before the next ignition. The falcon upper stages may do a second ignition to put a payload into a transfer orbit, or it may do a burn to deorbit into the atmosphere, where most of it burns up during reentry.

    I assume Starship will coast to the moon. Is effort needed to keep the fuel chilled the entire way?

    I believe that all moon missions, so far, have coasted to the destination, until the burn(s) needed to capture into lunar orbit. The main way cold propellants are kept chilled is through similar concepts that the Thermos™ container uses. These are well understood technologies.

    wayne said it is very cold in space, but it is warm or even hot on the sun side of the spacecraft.

    Once the engines fire to slow Starship down to orbit the moon is an explosion possible?

    Explosions are alway possible in all space missions, but they are rare. There are many ways — more likely ways — for things to go wrong. This is why Starship and Super Heavy are still in development. SpaceX is searching for correct ways to do things and the collateral result is that they find ways to not do things. Ignorant journalists say that these were failed launches, but they both were huge successes, going farther than their goals. When SpaceX publishes a launch profile, it contains everything the system will try if it succeeds beyond expectations. This is what happened with the first bellyflop landing test. They expected that they were going to have to learn how to get 100 tons of metal to make a rapid flip at the top of its climb. It worked the first time, and they were able to learn more about how to land in a unique way.

    As they are discovering, some of the methods that they used with the falcon boosters do not scale up to Super Heavy or do not give the desired performance.

    Does the vacuum of space make liquid fuel more manageable?

    Propellants are kept in containers (tanks) similar to use on Earth. Management is similar in vacuum as in atmosphere.

    However, propulsion performance is somewhat better, because the lack of atmospheric pressure allows the exhaust gasses to exit the engine at a faster speed, giving a greater acceleration to the spacecraft.

    The free fall of space makes liquids harder to manage, because gravity tends to settle liquids at the bottoms of their containers, and free fall tends to not have an up or down, top or bottom. Other methods are needed to settle liquids in their containers or to direct their flows through tubes or along defined paths. A cup of coffee is easier to drink in the gravity of your kitchen than in the free fall of the ISS.
    Doubting Thomas wrote: “… After all, Tim Dodd suggested something to Elon which was the basis for making a (minor) but helpful change to the booster.

    My recollection is that Dodd asked a question similar to, “why don’t you …” and in answering, Musk had to think about it and could not figure out why not. I mention this not to correct the “suggested” with “asked” but to bring up an engineering concept.

    When an engineer is asked “why do you do it that way,” the worst answer is “because we have always done it that way.” If the engineer cannot answer the question with facts, then he needs to do some homework.

    Before Falcon, when engineers were asked why they didn’t make reusable booster rockets, they had some empirical data to fall back on. The Space Shuttle was supposed to be inexpensive, economical, and reused frequently, but it wasn’t. The lesson learned was the wrong one, that reusability was possible, yes, just not practical. The correct lesson was that the Space Shuttle was the wrong way to do reusability. Falcon, Dragon, SpaceShipTwo, and New Shepard are examples of practical ways of reusability, and they should be able to be improved upon by Dream Chaser, Neutron, and Starship.

    SpaceX, Blue Origin, and Virgin Galactic now do the impossible, reuse boosters and spacecraft in a practical manner.

    SpaceX also does many things in public that we engineers were taught to never do, and we were given practical reasons with bad experiences to back them up. Empirical evidence says not to build rockets in open high bays or to store flight hardware outdoors, uncovered, yet there it all is at Boca Chica. It is also said to use a flame deflector and water deluge, yet there was SpaceX, learning that lesson all over again. Well, at least they tried. Not every terrible idea can turn out to be brilliant, but maybe it will save time and fuel to catch rockets with chopsticks, as though they were flies in a fictional movie.

    So the proper answer to these kinds of questions may require some homework to figure out how to make what seemed impossible possible.

  • wayne

    I’m going to drop this in here–

    Wherein Elon talks Fish & Wildlife, buying a fishing license, rockets hitting sharks, rockets hitting whales, and subjecting Seals to recordings of sonic-booms, twice.

    -cued to the relevant part.

    Elon Musk: War, AI, Aliens, Politics, Physics, Video Games, and Humanity
    Lex Fridman Podcast (Nov 8, 2023)

  • Jeff Wright

    To Edward,

    You suggest that Shuttle was the wrong way to do re-usability.

    I can only meet you halfway on that one.

    Falcon is a known quantity at this point…with Starship, I am not so sure.

    Now, unlike Falcon—which is narrow and only is handled at its base…Starship is pulled up by Chopsticks like how toddlers sometimes try to pick cats up by the throat.

    Could the very act of reusability here…all the recent stacking, destacking, restacking—could that be the reason the nose broke free…even not doing an “Adama Maneuver?”

    I like the idea of a Buran type Shuttle 2 in that you keep all the main tankage outside the airframe.
    The Energia/SLS does one burn as stage-and-a-half, then done.

    A wet workshop needs no TPS and does not have to face all the handling stresses an more eggshell Starship does.

    Now, I think a good Shuttle 2 would be like Energia with perhaps single use aluminum engines as recently tested…or perhaps an engine block/kerosene tank pod with a heat shield to parachute down, with an ET like all LOX main tank made from the start to be a wet workshop…maybe with a forward cargo carrier.

    With no SSMEs on the orbiter (flying heads up), the OMS go where where the RS-25s went and you have jets atop the wing so you have a full airplane upon re-entry.

    The tanks stay in orbit as floorspace. They only really get abused one time during launch, and are less prone to stress fractures all the manhandling of Starship may be inflicting.

    They baby SLS for a reason.

    I want that as an Energia for a simpler, safer Buran type Shuttle 2.

    Stretching the tankage might even allow something like this:

    Yes SLS is costly. So will launching 20 Starship tanker flights for a Moon mission.

    And that’s really not much of a different profile
    than what you see here:

    A Buran type Shuttle 2 is lighter not having SSMEs so maybe you could get away with a lunar mission, especially if the Energia type LV remains attached.

    The important thing is that the tankage is not to be manhandled like Starship…but left as living space…not being part of a vital airframe.

  • Jeff Wright

    I forgot—an SLS core alone may get to Luna:

    I could see Starship helping to put LOX in it :)

  • wayne

    “We were forced to kidnap a Seal, strap it to a board, put headphones on the Seal, and play sonic-boom sounds to it, to see if it would be distressed. This is an actual thing that happened. This is actually real.”
    (“The amazing part was how calm the Seal was, because if I was a Seal I’d be like, this is the end, they’re definitely going to eat me.”) (“We had to do it twice, btw.”)
    Elon Musk (11-9-2023)

  • Max

    More analysis by others who watched the replay of separation speculate that the thrust of starship was excessive, pushing the booster away more than intended.
    The three engine thrust of the booster may have been inadequate to prevent sloshing. The rapid movement of the empty upper part as it turned is evidence that it had little mass, but this changed as the lower half of the booster begin to flip rapidly (which is expected having the thrusters) but appears to pivot around the center of mass indicating that the fuel is now located at the top of the rocket causing the flip to be excessive. This is also is complicated with the uneven relighting of the engines.
    There is also speculation about a ruptured oxygen supply line. (thought to be corrected, from zero stage disconnect port?) oxygen levels deplete rapidly after separation according to the tank gauge. Perhaps the reason for that excessive booster flipping? More evidence to ponder on what corrections to make.

    The hot ring will become obsolete when thrusters for lunar/Mars landing are placed near the top of starship as in prototype designs. (it is thought that the concrete chunks damaged the thrusters on the first attempt, can you imagine the damage that would occur on the bare lunar surface?)

    As for “anti-sloshing baffles”, this technology has been explored and perfected for fighter aircraft. Some solutions are as simple as a flexible pick up tube with a weighted end which follows the fuel to whichever side of the tank the fuel is on. (free fall is to be avoided)
    Inflating bladders to fill the void solves the problem but adds weight and complexity. There are not many materials that are flexible without cracking in extreme cold temperatures.
    Spring loaded ratcheting pressure plate might be the simplest answer, modeled after the modern skyscraper elevator. Not only would it be self- actuating, keeping the fluid on one side, but the auto pressure release mechanism will allow refueling in zero G without opening the tank for resetting the hardware. Win win. One way valves in the pressure plate (similar to your wet/dry shop vac) will allow vapor to pass through but not fluid keeping the pressure in the tank equalized without an additional gas pressure tank. It will also allow fluid that escapes, or condenses, to flow back to the other side of the pressure plate during thrust. Precision fitting will not be required. Less moving parts means less can go wrong.

  • Jeffrey

    Goes Toll

    “Woman on the moon”

    First of all, no one in the Obama/Biden Regime can define what a woman is, so how do they get one to the moon?

    That said, perhaps Elon should announce that one of the main SpaceX goals is the first transgender person on the Moon and Mars. The gov wackos could possibly give SpaceX carte blanche for multiple launches. Heck, Elon could put the LGBTQWERTY rainbow on the side of Starship.

  • Mike Borgelt

    “A $100+ billion exercise in political pork branded with a Barbie objective.”

    Now *there’s* an idea for the next Barbie movie – Barbie on the Moon.

  • Questioner


    You hit the nail! Great!

  • pzatchok

    As for fuel sloshing they could go so far as to add a floating lid inside the fuel tanks,
    It would float on the top of the fuel and ratchet down as the fuel is used. Or an inflatable balloon could hold it down.

    They could even split the tanks into two for each fuel and the smaller one of each is to only used during the decent and flip. Thus no sloshing in the full second tanks.

    The excessive kick to the side the first stage experienced could be lessened and as long as it is not pointed at the second stage the three center engines could be fired faster but softer to help keep the fuel down Then execute the flip slow and controlled.

  • Jeff Wright

    I think there is a flexible substance that withstood cryogenics…

  • Edward

    Jeff Wright,
    You may want to rethink your fixation on Buran. It was not economical enough for the Soviets or the Russians to launch a second time. It is hard to say whether it had the advertised capabilities, because virtually none of them were tested in flight.

    Copying the Shuttle was also the wrong way to do reusability.

    Other than your one linked video of amateur observers, I have heard, read, seen nothing about Starship’s nose breaking free. What they claim to be the front flaps are far larger than the flaps SpaceX assembled on Starship. Starship’s flaps are not larger than the diameter of the spacecraft. You may want to confirm the analysis of the detached nose, because if the nose detached, where was the rest of the ship?

    But if the lift points are weak points, then there is an easy and obvious solution.

    By the way, Falcon 9 is lifted off the drone ship by the top of the fuselage, then rotated onto the truck.

  • Big D

    Edward: In the chat alongside that video, Scott Manley commented that by the time Starship was passing the Florida Keys (where the video was taken from), the AFTS had already gone off. He suggested that the payload section of Starship, being unpressurized, survived the self-destruct relatively intact, whereas the aft 2/3rds (the tankage) was obliterated.

    In short, the front end didn’t fall off; it was pushed!

  • Edward

    Big D,
    That would explain why there was no rest of the ship. I am still waiting for an authoritative confirmation. I would think that this would be big news.

    I mean, really big news. Range safety problem big. Failure of the improved flight termination system big. Cannot fly until this new problem is fixed big. Musk unable to announce another possible test flight before the end of the year big.

    But we aren’t hearing about such a terrible, overriding, holy failed-FTS Batman! problem, are we?

    Instead, I am hearing that the FTS worked exactly as intended. Do you think leaving a tens-of-tons nosecone intact would be intended?

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