Successful static fire Raptor engine test on 4th Starship prototype

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Capitalism in space: SpaceX yesterday successfully completed the first static fire Raptor engine test on its fourth Starship prototype, laying the foundation for a planned 150-meter vertical hop later this month.

The test lasted about three seconds.

I want to make a quick comparison between SpaceX’s approach for developing Starship, and NASA’s development of SLS. The differences are stark.

First, SpaceX began cutting metal a little over one year ago, and is already testing a full scale prototype, fully fueled, with its planned flight engine.

SLS began development officially around 2011. It uses the engines from the Space Shuttle, so those are already flight proven. However, even after almost a decade of development NASA as yet to do a single static fire test with those engines actually installed on an SLS rocket, either a prototype or the real thing.

Second, in the past year SpaceX has been aggressively testing the fueling of Starship, using a series of prototypes. With this fourth iteration they have apparently gotten the fueling process and the tanks to work effectively. Further tests of course will increase their confidence in the system’s reliability.

SLS, even after almost a decade of development, has yet to do any similar tank tests. Instead, NASA has done separate individual tests of the rocket’s tanks, but never with everything fully assembled. The agency, and its lead contractor Boeing, hope to finally do their first full scale SLS tank test and static fire test sometime later this year. As they have never filled the tanks in this manner before, they have admitted that problems could arise, including the possibility that the tanks could leak.

Note the big difference. SpaceX has done this testing very early in development. NASA is doing it very late in development. Which to you seems the better approach?


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  • geoffc

    SpaceX is testing SN4, and have SN5 waiting for space on the test pad. And parts of SN6 are already appearing in the various spy photos.

    SpaceX has an assembly line for Starships, and it looks like pad space is going to limit their testing, not construction time, for the near future.

    What a great problem to have.

    Next SLS core is due when? 2023? Next Starship SN is next week or two. Then SN6 is due a few weeks later, followed by SN7…

    Which is a better approach?

  • NavyNuke

    Everyday Astronaut also posted a comparison of SLS and Starship a few days ago. I thought it was well done.

    I wonder how New Armstrong is coming along.

  • James Street

    A few years ago I read an article that Elon Musk was using the Agile project management style to build rockets that is used in software development and divides projects up into 2 week sprints. Traditional project management uses the Waterfall method where time lines, tasks, milestones, resources, costs and so on are planned, followed and tracked over the life of the project which can be years.

    The article didn’t give Musk much chance of success building rockets using Agile.

  • pzatchok

    When you don’t make your money building rockets but flying them, you tend to have faster construction, upgrade and turn around time.

    And he is not making “upgrades” in technology just to do it. He uses what is proven off the shelf tech.

  • wayne

    I’ll toss this in here—

    Joe Rogan Experience
    #1470 Elon Musk (is back for a chat)
    May 7, 2020
    [3,400,128 views and rising]

    (wherein, Musk does explain the unique name of his new child)

  • David M. Cook

    I wonder how he handles the problem of ”engineering creep“? As soon as you make something, you then know how to make it better, leading to endless redesign.

  • Edward

    David M. Cook wounded: “I wonder how he handles the problem of engineering creep’?

    Most engineering organizations “freeze” the design, at some point. SpaceX does two additional things. 1) Early testing on completely new hardware allows for improvements to be learned on one unit and implemented on the next unit or the one after. 2) SpaceX is very willing to forsake efficiency in favor of price to the customer and timely start of operations.

    Oh, there is a third thing that SpaceX has done. Falcon 9 went through iterations with each launch. It seems that up to reusability, no two launches used the exact same design on the launch vehicle. On the other hand, this is more like my first point and less like a design freeze.

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