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Official Raptor Engine testing is beginning

Discussion in 'SpaceX' started by Grendal, Aug 9, 2016.

  1. Grendal

    Grendal Active Member

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    Posted on twitter by C. G. Niederstrasser:

    Shotwell - just shipped first Raptor engine to Texas last night. #SpaceX #smallsat


    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]

    I suppose we'll find out whether this is an official raptor engine they intend to mass produce or a testing version of the concept. Hopefully we'll get some videos soon.
     
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  2. HVM

    HVM Savolainen

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    Last time I heard it was: SpaceX is testing Raptor engine components at NASA's Stennis Space Center. (2014) "According to SpaceX they are still in the very early stages of the Raptor engine development program and this initial test phase will last 12 to 24 months with larger components to be tested afterwards presumably at their rocket engine development facility in McGregor, Texas."

    This time SpaceX's timetables seems to be holding :)
     
  3. Patrick W

    Patrick W Member

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  4. Grendal

    Grendal Active Member

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    Oops. I should have included that detail as part of the announcement. Thanks for posting.

    Here is an overview of the type of engine they intend to have:
    Staged combustion cycle - Wikipedia, the free encyclopedia

    So the one big weakness in the Merlin 1D FT engine, as mentioned by Elon, is that it is an inefficient open cycle gas generator cycle engine. It has lots of advantages and it makes a lot of sense why SpaceX went with that type of engine it is off the bat. The Merlin is a simple straightforward engine. It has the prestige of being the highest power for its size of any other orbital launch engine. But like the Model S, Elon wants his rocket engines to be better in every way than every other rocket engine made. The Raptor should achieve that. The advantage of the system they intend to use Is that it is intended to be a reusable engine while being more powerful. It will run at a lower pressure and burn cooler than the efficient throw away staged combustion engines like the Russian RD-180.

    The Raptor is the engine that SpaceX wants for the future.

    You will probably be hearing about BO's BE-4 Methane/LOX engine in comparison to the Raptor Methane/LOX. The BE-4 will be using a Merlin style open cycle engine with the Methane/LOX combination. So not as difficult to make or as efficient as the Raptor will be. FYI.
     
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  5. Patrick W

    Patrick W Member

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    Any ideas why they want to go with methane instead of hydrogen? Hydrogen + Oxygen = only heat and water. Same can not be said for methane. Plus I seem to remember the hydrogen has a higher specific impulse.
     
  6. scaesare

    scaesare Active Member

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    You can make methane on Mars.
     
  7. Bangor Bob

    Bangor Bob Member

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    If you have methane, you can make hydrogen. Methane IS easier to handle though.
     
  8. RDoc

    RDoc S85D

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    Hydrogen has a much lower boiling point as well as a bunch of other pretty nasty chemical characteristics.
     
  9. Patrick W

    Patrick W Member

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    And with all of the water ice on Mars they could make lots of hydrogen.

    But maybe since methane is such a potent greenhouse gas they want to use it to warm the atmosphere (I'm only half serious about that. :) )
     
  10. cronosx

    cronosx Member

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    So, if i read correctly the Raptor will have a lower thrust force, but it will be more efficent means less methane/oxigen needed for the same thrust?
    This is of course a HUGE advantage since the fuel make up most of the weight..
     
  11. HVM

    HVM Savolainen

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    #11 HVM, Aug 10, 2016
    Last edited: Aug 10, 2016
    BE-3 is a open cycle engine (tap off e.g. open) and BE-4 will be a single-shaft oxygen-rich staged combustion one (all of the oxidizer and a portion of the fuel are fed through the preburner e.g. closed).

    Atlas V's rd-180 uses oxygen-rich staged combustion.
    Shuttle's rs-25 uses fuel-rich staged combustion.

    Raptor uses a full-flow cycle where both of the propellants go through the preburners. Only two Full-flow staged combustion engines were build in the history of rocketry, and both never flown...

    Advanced/hard to do + efficient
    open < fuel-rich < oxygen-rich < full-flow
     
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  12. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Active Member

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    And if you're trying to make a reusable engine, nasty chemical characteristics are really not desirable.
     
  13. Grendal

    Grendal Active Member

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    Elon posted a tweet about the new Raptor engine testing:

    Elon Musk on Twitter
    Elon Musk on Twitter

    Elon:
    "SpaceX propulsion just achieved first firing of the Raptor interplanetary transport engine"

    And more:
    Elon Musk on Twitter
    "Production Raptor goal is specific impulse of 382 seconds and thrust of 3 MN (~310 metric tons) at 300 bar"
     
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  14. Grendal

    Grendal Active Member

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    And even more:
    "Chamber pressure is almost 3X Merlin, so engine is about the same size for a given area ratio"
    Elon Musk on Twitter

    And go to his tweets to see the photos of the engine firing.

    Nice timing to go with tomorrows big presentation.
     
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  15. HVM

    HVM Savolainen

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    I hope a video after International Astronautical Congress Mars Architecture presentation. (And more)
     
  16. HVM

    HVM Savolainen

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    #16 HVM, Sep 27, 2016
    Last edited: Sep 27, 2016
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  17. ICUDoc

    ICUDoc Member

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    Wow! That looks fantastic!
    Really looking forward to the next big rocket from Spacex- I loved physics and space as a child / teen; was stupid enough to do (terrestrial) Medicine. But I'm living vicariously through the Internets now....
     
  18. ecarfan

    ecarfan Well-Known Member

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  19. Grendal

    Grendal Active Member

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    Elon commented that he was pleased that the engine did not "blow up." It didn't and Elon seemed pretty pleased that it would work as well as SpaceX planned.

    I'm impressed that they are choosing to go with a whole lot of these engines.
    42 engines.jpg
     
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