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Cake day: February 28th, 2024

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  • I still remember the press conference before the first F9 booster reuse. The customer CEO(?) was saying that his team was comfortable, and I think even that the insurance company was comfortable too. So I was fairly confident it would work.

    In this case, there’s no customer or insurance company giving any high level push-back on any concerns.

    One possibility I wonder about is that Musk and/or other senior SpaceX ppl might be wanting to ‘double down’ on how this is a bold & risk-taking programme, for psychological reasons, in defiance of all the naysayers after the Flights 7 & 8 situation. And thus ignoring the ‘critical path’ argument, and the fact that the only good risks to take are calculated risks.

    Do you think the cost of booster production could be a factor in their decision?

    Unsure about this topic in general. My guess is that the raw materials and COTS components are relatively cheap, and that most of the costs are labour. So one uncertainty lies in whether the people would be employed at Starbase regardless of whether they had to build an extra booster or not. And just in general, when we hear dollar figures bandied around, what proportion of those are the true ‘marginal’(?) cost.

    But ultimately I think yes, now you mention it, cost would’ve been a significant factor in the decision.

    Along with maybe production rate? Maybe they can easily shift existing people & factory space from boosters, to ships. And so the full ‘critical path’ argument needs to take into account how booster reuse could potentially increase the ship production rate.


  • Well I certainly wouldn’t want to launch on an F9 booster on its first flight![1] And NASA recently gave a clear sign that they share that logic to at least some extent.[2] So I’m definitely open to that possibility, for Super Heavy, and maybe SpaceX already believes it.

    But as an outsider my guess is that, if nothing else, the ‘unknown unknowns’ should give us significant concern on the first attempt. I’m guessing a 20% probability that the booster reuse significantly hampers Flight 9.


    [1] - Nor on its 2nd actually. My theory is that there could be manufacturing defects in/around the reusability hardware that don’t get stressed until after the main stress of the first flight, which the second flight then uncovers. E.g. a landing leg attachment fitted imperfectly causes a crack in the rocket body during the 1st landing, and the crack causes a RUD at max Q during the 2nd flight.

    In other words the first section of the bathtub curve might not be as steep as we’d like.

    [2] - I think within the last year there was a problem during transport of a brand new F9 booster, and NASA said they were glad to subsequently give it a test flight on a Starlink mission before it was used for a NASA mission.



  • SpaceX has spent several weeks refurbishing, testing, and preparing Booster 14 for its next flight, which is planned to be on Starship’s next flight, Flight 9. The company also announced that 29 out of the 33 engines on the booster are flight-proven,

    I wonder if this decision is a mistake. Seems like ship development is on the critical path, and booster development is very much not.

    If the estimated increase in risk from the reusing Super Heavy for the first time is substantial, it might be better to delay that until some more progress has been made with Starship.










  • ptfrdtoSpaceflightMemesTechnically correct, but what a headline
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    4 months ago

    I don’t remember NASA mentioning anything like that - either at the briefing I’ve just come across, or any other time they’ve talked about it.

    So my guess is that they didn’t bother. Just hoping that whatever could cause the crew to have to return to Earth in a hurry wouldn’t also cause any problems with the cabin air in Dragon. (Problems like … there not being any! Or it being filled with smoke, or ammonia.)

    Perhaps they would’ve gone with your plan if they’d had all the necessary equipment.



  • ptfrdtoSpaceXNext Crew Dragon mission delayed a month
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    4 months ago

    The delay does give extra time in space for the Crew-9 crew.

    Best guess. Williams & Wilmore will be disappointed by this. But Hague & Gorbunov will be pleased, because it extends their stay to 6 months (which is the standard duration, and was the intended duration when they were first assigned to the mission).


  • ptfrdtoSpaceXNext Crew Dragon mission delayed a month
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    4 months ago

    This means Butch & Suni may actually still be up there at the start of April! If so, their mission managers should solemnly inform them of a substantial further delay (as an April Fools’ Day prank).

    The managers could claim that a review had discovered the possibility for out-of-family COM (centre of mass) scenarios in the capsule as a result of the changes to the crew complement.

    “As you both surely know, assumptions about the COM are built in to multiple systems throughout the vehicle. If things go wrong, the worst case scenario could involve both helium leaks, and an unexpected thermal load on the thrusters, leading to malformation of some Teflon seals and a potentially significant loss of thrust … oh no, hang on … that was Starliner not Dragon. Sorry about that guys. My bad. April Fool!”


  • ptfrdtoSpaceXWhat is SpaceX hiding at Vandenberg?
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    4 months ago

    An army of alien drones, preparing to conquer Earth on Christmas Day. Hiding at Vandenberg and many other military bases around the world.

    ;)

    Or could it have just been so foggy on those occasions that some overworked SpaceX employee decided not to bother with any coverage until the rocket was clear?