Musk Says Change Anything for Faster Development and Forget Sunk Costs

Elon Musk had an interview with the Everyday Astronaut.

Elon reiterated that he changed to steel construction for the rocket when carbon fiber was taking too long. Carbon fiber was a standard in the rocket industry.

SpaceX Falcon Heavy use of composites for the fairing (payload nosecone cover). The interstage, which connects the upper and lower stages of the rockets, is a composite structure with an aluminum honeycomb core and carbon fiber face sheets.

In December 2018, nine months after starting construction of some parts of the first test article carbon composite Starship low-altitude test vehicle, SpaceX CEO Musk announced a “counterintuitive new design approach” would be taken by the company. SpaceX switched to stainless steel construction.

Elon says:

All engineers at SpaceX need to have some perspective of a chief engineer. Everyone in engineering at SpaceX needs to understand all of the parts of the whole system they are building. They need avoid having engineers optimizing just one part. The engineers need to question the contraints that they are being given. This can only be done if they understand the whole system.

Elon says:
One of the most common mistakes of smart engineers is to optimize on a part or process that does not need to be present. If the whole system is understood and the purpose of processes and parts is understood then it is possible to eliminate parts and processes.

There is a final discussion of the aerospike engine. The aerospike has greater theoretical efficiency. Elon indicates that with their two-stage rocket, they can optimize the booster with sea-level optimized engines and the upper stage can have vacuum optimized engines. This reduces the practical need for an aerospike.

SOURCES – Everyday Astronaut, Elon Musk, SpaceX
Written By Brian Wang,

38 thoughts on “Musk Says Change Anything for Faster Development and Forget Sunk Costs”

  1. “The LCROSS mission was a game changer,” NASA’s chief Jim Bridenstine told Reuters, adding that once water had been found the United States “should have immediately as a nation changed our direction to the moon so we could figure out how to use it.”

  2. Again, I have no problem with Musk. Certainly O’Neill Space and even the Moon are *given* if Mars is possible. Still need *more* lunar ISRU, and mercy for SLS, but that is still within a Mars outlook, which I accepted by stipulation to argue Moon-then-Mars over Mars Direct. You are correct, his Mars rockets should get a mass driver on the Moon much earlier than having to do smaller iterations of ISRU/bootstrapping. They may even allow Mars Direct.
    But I am hoping he suddenly goes crazy and joins Bezos in building Space Solar Power to solve global heating. I continue to see no non-science benefit to Mars, compared to Globus ELEO for example. The utterly counter intuitive answer to O’Neill’s question has drastic impact on what to do. But it is not quite yet on the table compared to Mars, which is just a given it seems. I’m pretty happy, by the way, compared to just a few years ago. Things are looking up!

  3. Musk has shown himself to be adaptable in his approach. I think that may be the case regarding the moon as well. You have presented a clear case, logically, over many posts. I would wager that in his ambitious thinking shooting for mars, anything closer would be a given. Surprised you do not see it that way.

  4. Car fires are usually due to oil leaks, not gas leaks; The ignition temperature of oil is below its boiling point, for gas it’s above its boiling point.

    As a consequence leaking oil dripping on the exhaust manifold can get hot enough to catch fire. Leaking gas dripping on it evaporates away before reaching that ignition temperature.

    Gas usually only catches fire in a car if there’s a spark to ignite the vapor.

  5. What are you talking about? The Moon? Who says it needs carbon? You have plenty of metals and water there that it’s basically a floating gold mine.

  6. In fact, the ONLY therapy that offers proven cures regularly. Very “weird”. Don’t even look at it. Esp. if you know anything about epigenetics or PTSD, adult or childhood.

  7. Of all the weird psychobabble cults that sprung up on the 20th century, the “Primal Scream” one was one of the weirdest.

  8. Actually, there were boosters built back in the late 50’s/early 60’s that used welded stainless steel structural propellant tanks. So it’s been done before.

    The construction method used for this Starship demo vehicle’s propellant tanks would obviously never be acceptable for a man-rated vehicle intended for a large number of launches with minimal servicing between flights. But it should be adequate for a couple short unmanned test flights. There are significant technical challenges with large fusion-welded propellant tanks, especially fatigue & fracture control around the weld joint’s HAZ. In order to show by analysis that a “low cost” fusion welded 301austenitic stainless steel propellant tank structure has adequate fatigue and fracture margins for its intended service life, would likely involve a significant weight penalty.

    The max room temp UTS you can assume in the weld HAZ for 301 wrought sheet is probably 73ksi. Applying a fusion weld knockdown factor would cut that in half. That’s why fusion welding is not used much for lightweight flight vehicle structures.

  9. I did have the fuel rail on my Nissan burst and spray fuel over the hot engine.

    Luckily I was able to shut it down without a fire and call the tow truck.

  10. And your fundamental mistake here is assuming everyone else on this site is a psychiatrist paid to listen to you vent your frustrations.

  11. I suspect your acceptance QC has to be heavier, because you’re not dealing with nearly enough parts to establish good statistics for whether your process is in control, the way we are in the automotive industry.

    Though our critical parts for fuel rails tend to be 100% inspected by automation, since any failure there can cause a car to catch fire. I think we’re moving gradually in the direction of just 100% inspecting everything that way, as the automotive companies are pushing to get the failure rates to 1ppb or lower.

  12. “social sciences (the whinny, teleological, history-has-a-goal-and-that-is-socialism kind)”
    Janov observed (as opposed to postulated) that healthy people, those who had succeeded in therapy, had a “live and let live” attitude and were very adept at meeting their own needs. Can you say “libertarian” with me!

  13. The bulk of the Moon is very low in any gas. It always had plenty of O, so O’Neill was ready to go with just that. Water is a much later bonus, as is C, as is Musk.
    I have no prob with Musk, but a biggie with US Mars focus, now known as SLS and related, which I’ve been fighting for over 40 years. Long before SpaceX was a dream.
    So, compromise by dropping SLS years ago and focus on showing Musk the wonders of O’Neill. He seemed weak in his Mars support at the Starship reveal, but that may have been wishful thinking on my part. Does not really matter now, as lunar ISRU seems to actually be starting. Let Musk learn at his own pace. Much as people need time to absorb facts about baby abuse presented so clearly and scientifically by Janov. Not all understand completely at first, but Primals do exist anyway. Therefore, Primal Science exists.

  14. But QC in old-timey aerospace doesn’t involve trusting your suppliers. Acceptance QC is much heavier-weight than automotive. Beyond that, there are so many piece-wise integration tests that a missed acceptance test isn’t that big a deal.

    I’m sure that SpaceX has a pretty decent set of piece-wise integration tests, too. But their acceptance tests are easy, because the guy fabbing the part for you is just down the hall.

    That’s why SpaceX built 80% of a giant spacecraft (admittedly the easy 80%) in about the same time that it took Boeing and Michoud to rehearse transporting the SLS core to the Cape.

  15. We’re subject to some pretty heavyweight testing here in the automotive industry. But none of it would actually stop us from slipping in a bad part and getting it installed in a vehicle, if we suddenly began faking our own inspections. QC in the automotive industry involves trusting appropriately certified suppliers to follow their own procedures.

  16. I suspect that you have cause and effect reversed there. In old-timey aerospace, you’d never have had that failure, because the acceptance testing infrastructure used for subcontractors wold be so heavyweight that the sub-standard parts would never have made it through. But that’s not the kind of infrastructure you put in place when you develop using an agile methodology.

    I think how SpaceX is doing stuff is exactly right, but it’s not without its costs. One of them is that adding any subcontracted parts or systems is more risky.

  17. I will give you this: The presence of carbon containing compounds in Lunar cold traps could be useful, even if the bulk of the Moon is very low in carbon.

    My take on this is that both Bezos and Musk have properly designed their infrastructure to take into account where they respectively want to go. Which does not have to be where you’d rather they went.

  18. Never underestimate the power of social engineering, the way Karl Popper intended it: the science meant to study the ways to organize human groups to achieve a goal, of which Agile and Lean methods are an unofficial representation in the guise of computer science and manufacturing methodologies.

    Not to be confused with social sciences (the whinny, teleological, history-has-a-goal-and-that-is-socialism kind) or the so-called “social engineering” methods for hacking.

    We really had to develop the right organizational mindsets and methods in order to finally have potentially cheap spaceships and spaceflight.

  19. Your fundamental mistake here, is failing to accept that others are entitled to have different goals from you, and pursue them instead of your own. Failing to do what YOU want done isn’t a mistake, it’s a choice.

  20. Having one of their rockets blow up due to a contractor shipping them fraudulently certified parts probably contributed to that attitude.

  21. You should really stop your strident preaching for O’Neill colonies. Complete with admonishments and poorly veiled insults for non-believers.

    It is annoying.
    And I say this as an O’Neill colonies supporter.

  22. This is soooooo much easier to do with Agile methodology. With old-timey aerospace methodology, In the beginning there’s the spec, and the spec then gets distributed to about 50 subcontractors, so that changing it is almost impossible. With Agile, there really isn’t any analogue to the spec; groups have to collaborate through every sprint, so at the very least, everybody at least has to know the details of the modules that interface to what they’re doing.

    There is a downside, though: doing multi-contractor projects is really hard. I suspect that that’s why SpaceX is so dead-set on complete vertical integration; they never have to cast an interface in stone if they own the development of everything involved in it.

  23. When Mars was the only thing on the taxpayer’s table, was yur position that the Moon deserved equal treatment? I supported Mars(as a stipulation), as long as it included lunar ISRU. There is yet to be the first US rover on the Moon in decades. Mars Direct is the *mistake* choice, has been from the start. Now, it is simply out of the way, thanks to Musk and his Musk Orbital Flying Object.
    The contracts to develop ISRU are finally starting to happen, so O’Neill has won. Starting an exponential growth with ISRU will beat any launched plan, esp with the bigger starting steps bigger rockets allow.

  24. I won’t deny that Mars has gotten more attention than the Moon, that’s obvious.

    I would deny “mistake”. Your fundamental mistake here, is failing to accept that others are entitled to have different goals from you, and pursue them instead of your own. Failing to do what YOU want done isn’t a mistake, it’s a choice.

    Let Bezos develop the Moon, and Musk develop Mars. I suspect Musk is going to beat Bezos to the Moon just incidentally, due to his much faster design cycle. Maybe Bezos will find it economical to hitch a ride with him.

  25. Mars would definitely be a mistake, if done in exclusion of lunar development. As has been the case for 40 years of heavy complaints by myself and others. You cannot deny that!

  26. “The engineers need to question the contraints that they are being given” … I can tell space x not yet corrupted by wasteful government s pending culture…. I feel that you could fire half of the engineers at Lockheed Martin Raytheon Boeing NASA at al. and it would actually
    improve the company by getting rid of the people that Slow everything down and try to damage things out of job security… You know… The requirement review team…that has no idea what as single requ8rement means… Because it’s a fake document to create employment in government defense industry…

  27. Yeah, let’s sink all our resources into extracting resources from a celestial body that almost completely lacks carbon. Who needs carbon anyway. (This is sarcasm if you couldn’t tell)

  28. “all non-scientific Mars plans must be recognized as sunk costs”?

    Who exactly was incurring such costs?

  29. I like the ideas that Musk is pursuing – especially the “Just because we’ve done it this way doesn’t mean we HAVE to keep doing them this way.”

    The way he’s planning on building Starship is innovative. And I think it’s got a good possibility of working.

    And to be honest? Success breeds success. He’s got a good idea of what needs to be done and how it needs to be done.

  30. Yes, all non-scientific Mars plans must be recognized as sunk costs, a wasted 40 years NOT doing lunar ISRU, which everyone seems to now support.
    O’Neill lives.

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