SpaceX Fires Up Raptor Engine

Just in time for Musk’s speech on Tuesday, an update on the Raptor engine for the transporter formerly known as Mars Colonial.

  • Sam Moore

    I know that chamber pressure would result in a relatively small combustion chamber, but it still looks much too small for that thrust. Could it be a subscale test engine?

  • Terry Stetler

    It’s possible. I’ve heard it said* that full flow staged combustion engines scale nicely, making the transition much simpler.

    * a SpaceX propulsion guy before a congressional committee.

  • That is a beast. 300 bar is 4351.14 psi or 30 MPa. That is a lot more
    than even the russian ORSC engines! For reference, M1D is about 10MPa,
    SSME is about 20MPa, and RD-170 is about 25MPa. RD-180 is 26.1 MPa and
    Angara RD-191 (which has the highest pressure ever fielded in a production rocket
    engine) is 26.2 MPa.

    They are making an engine with a “new” propellant type, a new engine cycle and the highest chamber pressure ever fielded.

    This is an EXTREMELY ambitious goal. Some more info.

    The vacuum nozzle is “pretty close” to 14ft (4,2m) in diameter.

    Raptor is using multiple stage pumps to pump the propellants to >45 MPa.

    ps: And if this thing blows btw, it takes everything with it. There is so much energy stored that you cannot talk about engine-out capability.

  • therealdmt

    At this point in time, I’d be more interested to read about more progress in their investigation, progress at getting their various launches facilities running, and further progress on their commercial crew milestones

    Still looking forward to the big reveal of course, but unless they can take care of business, it’s gonna be just another in a long line of Mars plans that have been put out since the days of von Braun

    A Raptor second stage, as for which development work is being partially funded by the Air Force, might allow them to have a kind of do-over and design around the various helium-related issues, however…

  • MarcVader

    Did you write this exact same comment on /r/spacex or did you copy it from there?

  • Michael Vaicaitis

    Business is F9 and FH and Dragon and Dragon 2 and R&D for future plans. They’ve 5000+ people working on many projects, and btw, there’s gonna be no helium with Raptor anyway.

  • ReSpaceAge

    Thought I read full scale somewhere but don’t recall where? Musk tweet maybe?

  • ReSpaceAge

    Is this test in texas? What happened to Stennis testing? Didn’t they test injectors there?

  • therealdmt

    Yeah, but you know they rushed to get this in before the speech (I read Shotwell recently mentioned that as an objective that they weren’t going to be able to reach). Seems like they’re taking their [collective] eye off the ball a bit here with this and the Mars architecture announcement.

    But hey, if they can return to flight in the next few months, launch Falcon Heavy early next year and get commercial crew at least manned flight tested in 2017, get their manifest in good shape and business hummin’, and move on to Mars, well, then more power to them!

    But, currently they’ve lost two vehicles/payloads in approximately the last year, can’t fly and America still has no independent access to space for even a single astronaut, let alone 100 to Mars or whatever. It’s really creating some mixed feelings with me in relation to the upcoming announcement. I wish they were holding off on that until after return to flight and a few success under their belt. But, whatever. As long as things work out in the long run

  • Yeah. So now we’ll be 2 deep in rockets that have yet to fly and 2 deep in capsules that have yet to fly (assuming a new vehicle for Mars transportation is announced). “We’ll build the NEXT next rocket right after we’re done with the NEXT rocket, right after we fix what’s wrong with THIS rocket.”

    Building the subsystems is 90% of the work. Integrating them is the SECOND 90% of the work!

  • ReSpaceAge

    30 plus engines with no engine out capability sounds like a disaster 🙁 would the spec. be different for BFS engines than the BFR engines?

  • Michael Vaicaitis

    “There is so much energy stored that you cannot talk about engine-out capability.”
    How can you know this?.
    Based on the F9 engine redundancy philosophy, it seems odd, if not totally unthinkable, they would go with such a bust and boom approach. BFR/MCT will be required to perform (preferably flawlessly) for many many consecutive missions without significant maintenance, so seems bizarre to select an engine design that is the antithesis of the fundamental requirements. Not saying you’re wrong, just questioning your air of certainty.

  • Michael Vaicaitis

    “Seems like they’re taking their [collective] eye off the ball a bit here…”
    No, I think it’s simply that they are developing at a rapid pace and some of the things they are doing are new (almost by definition, since all rocket designs are pretty much unique). Developing fast pays off with regular and significant jumps in capability, with the downside of potential regular issues to overcome – some catastrophic.

    ULA and Arianespace can tout past reliability (until they move to new architectures), but the cost is not sustainable – which is why they are moving to new architectures. Are there any other industries held to such a high standard by onlookers as space, particularly space launch?. Things go wrong from time to time – fix and move on.

  • ReSpaceAge

    I don’t know…..we will learn tomorrow I guess

  • ReSpaceAge

    Yup!!

    It’s called having and working on a real plan!!!!!

    Nasa’s “Journey to Mars” SLS/Orion joke

  • ReSpaceAge

    From the time the Wright Brother flew till the first 747, I wonder how many planes crashed do to mechanical failure? Wasn’t that only about 50 years?

  • Michael Vaicaitis

    “There is so much energy stored that you cannot talk about engine-out capability.”
    How can you know this?.
    Based on the F9 engine redundancy philosophy, it seems odd, if not totally unthinkable, they would go with such a bust and boom approach. BFR/MCT will be required to perform (preferably flawlessly) for many many consecutive missions without significant maintenance, so seems bizarre to select an engine design that is the antithesis of the fundamental requirements. Not saying you’re wrong, just questioning your air of certainty.

  • Michael Vaicaitis

    sorry mate – my comments were aimed at Dante80 – pressed the wrong Reply button.

  • Michael Vaicaitis

    You are quite correct. If an F35 were to crash onto an aircraft carrier, cause $100million in damage and kill 50 – they’d fix the problem and go again. If a passenger jet goes down and kills 300 plus the $300million aircraft – they’d fix the problem and go again. If a ship sinks killing 1000 – they’d fix the problem and go again. If a horse got spooked and a stagecoach crashed killing all occupants, the wouldn’t have “grounded” all horses, coaches, and wagons for years until all horses could be made unspookable. I hate to sound so flippant about death and destruction, but that’s the way the real world works and always has worked.

  • Well, I think it is simply a matter of the potential energy stored in the chamber and the pumps. We do have an example from a 15 MPa ORSC engine RUD in the Antares Orb-3 mission. The Raptor seems to run at double that pressure in the chamber, and triple that at the pumps.

    The relation between internal pressure and released energy potential is not actually linear either.

  • Regarding pressure? No idea, Elon was talking about the vacuum variant in the tweet that said 300 psi pressure. It is impossible to reach 382s Isp with a Methalox booster engine anyway (due to the propellants used and the much smaller expansion ratio needed for atmospheric flight).

  • Michael Vaicaitis

    Well it’s a matter of how much of the blast (explosive force) would go down and out anyway, and how much would need to be contained. Then, how much (armoured) shielding would be needed to isolate each engine from such an event and how much mass that would consume. Obviously, I don’t have those answers, and, I fully appreciate the rather persuasive point you are making – it does seem decidedly non-trivial to replicate F9 at these higher energies – what would the ratio of blast force to shielding area be?. If they’re gonna stick 20-30 engines (we’ll find out tomorrow how many) on BFR with NO engine out capability, then disaster seems all but certain.

  • windbourne

    Aerospace, medical, nuclear power, chemical reactors, work at CDC when using bugs like ebola, smallpox, etc, etc, etc

  • windbourne

    Hopefully this is stennis. Texas really needs to be devoted to production of rockets , not so much r&d.

  • Sam Moore

    I’m pretty sure it is, when Shotwell said it was being shipped last month she said it was going to McGregor.

  • Texas does not produce rockets. It test fires them, and then sends them over to the Cape or California for launch.

    Thus, McGregor is actually a pretty natural result for test firing a new rocket engine. Which is why the Raptor test was made in a dedicated stand, away from the production hardware.

  • Vladislaw
  • Andrew Tubbiolo

    Those numbers are extreme in every sense. And that Isp is astronomical for a petrolium fueled engine. It’ll take a while for this engine to firm up and become stable.

  • windbourne

    there is R&D of rockets and then PRODUCTION of rockets. Part of PRODUCTION of Rockets, includes testing them. After all, if they fail the test, they back to CA to be fixed.

    But was Raptor done at McGregor or at Stennis?

  • windbourne

    hmmm.
    That must be all flights, not just commercial.

  • Raptor components were tested at Stennis. The whole package is in McGregor now, and had its first test fire yesterday.

    We don’t know whether this is a scaled model or not, the evidence and info we have is conflicting.

  • Douglas Messier

    I expected SpaceX to come out with some preliminary conclusion on the F9 accident before Elon’s talk. And to do a test fire of Raptor before then as well. The first partly removed a cloud over the event. The other provides some much needed credibility to what he’s about to propose.

    Clearly, this engine has a long way to go. I’m betting they pulled out all the stops to make sure they tested it in time for the talk. I wonder what other more important priorities were shelved to get this done.

  • windbourne

    I wish that they had left it in Stennis instead. McGregor really should have produciton only. The town ppl are going to get tired of it.

  • windbourne

    with 5000+ employees, hopefully none.

  • patb2009

    it’s hard to contain that energy when it blows.

  • publiusr

    Good news!