• Mr Snarky Answer

    Raptor has been on the test stand for a little more than a week and already running at higher thrust than BE-4 (Which is stuck at ~70% throttle until re-design is complete). SpaceX’s approach to iterative full engine design seems to be superior than Blue’s jump into complete engine at full scale. That one year lead Blue had on SpaceX just evaporated.

  • Pete Zaitcev

    At 172 tf, Raptor is much smaller than Russian engines from Glushko’s family, where even the single-chamber RD-191 pushes 212 tf. The BE-4 is claimed to give about 227 tf, once complete. I think the successful history of gradual development of Merlin is a great guide and is one reason why Elon decided to start with relatively small thrust engines in the Raptor generation too.

  • Andrew Tubbiolo

    Rocket engine technology is edging into a new era. The coming engines running at extremely high chamber pressure represents a real advance in the technology. This has been in the works now for coming on 7 years. It’s not just happening. Space X’s advances in tooling and manufacturing shows in the crazy high efficiency numbers of the Merlin and the fact that they manufacture incredible numbers per year and their refurb/reuse is also very impressive. Future versions of Sutton and similar books will have chapters dedicated to this era. The specific power of SpaceX engines is really impressive.

  • Terry Stetler

    The “full thrust” Raptor will have about the same thrust as BE-4 but be smaller and lighter, translating to an insane thrust to weight ratio – higher than Merlin’s 200:1. RD-191’s thrust to weight is 89:1.

  • Steve

    And SpaceX is only 20 years behind the Russians. Are we really comparing schedules, especially any date published by the calendar-challenged SpaceX ?

  • Mr Snarky Answer

    Adjust your meds. How is SpaceX 20 years behind the Russians? In avionics, structures, reusability? How’s that Angara program going? How’s that commercial launch business going in Russia?

    SpaceX has only been around for 17 years…and from dead stop to F9/FH/Dragon2/ Raptor FFSC engine at higher pressure than RD-180. That is an amazing schedule success.

  • Mr Snarky Answer

    Yes hit hits a lot of high points. It will be an efficient cycle and high T/W and modest scale for affordability. Also FFSC means elimination of common shaft seals and lower peak turbine temperature for reusability. Should be very interesting.

  • ThomasLMatula

    Are you referring to the same Russians flying spacecraft to the ISS that are from the Apollo Era?

  • Steve

    But the RD-170 family of engines has been around for more than 20 years. Give yourself a pat on the back for sorta duplicating old Russian technology stupid fanboi. If they want to copy the Russians, maybe they can bring back Sea Launch.

  • redneck

    Thus demonstrating that you don’t know the difference between staged combustion and full flow staged combustion.

  • ThomasLMatula

    Old Space Strikes Back…

    https://www.bloomberg.com/news/articles/2019-02-12/spacex-launch-certification-to-face-review-by-pentagon-watchdog

    SpaceX Launch Certification to Get Review by Pentagon Watchdog

    By Anthony Capaccio

    February 11, 2019, 9:22 PM CST

    Updated on February 12, 2019, 11:53 AM CST

  • voronwae

    There’s little similarity in the engineering solutions employed for Raptor vs those used for RD-170. The words you’re saying don’t mean what you think they mean.

    And as far as high pressure and staged combustion go, Pratt was doing it with hydrogen simultaneously with Glushko in the 1960’s, only designing for civil aviation levels of reusability. Glushko’s ceramic coatings don’t do so well for shelf life or longevity.

    No magic here, just lack of desire and politics. SpaceX is revisiting Pratt’s achievements.

  • Jeff2Space

    Agreed. Full flow staged combustion is the holy grail of liquid fueled rocket engine cycles. As far as I know, SpaceX will be the first to actually fly a full flow staged combustion liquid fueled rocket engine. That puts them squarely ahead of the Russians.

  • windbourne

    SpaceX is working on Nuclear Thermal engines as well. I hope that they are making progress on those.

  • windbourne

    Yes, we know that Elon is date challenged.
    However, as the saying goes,
    Elon is slow, and yet, nobody can catch up with him.

  • windbourne

    Angara is brand new, but not working right.

  • windbourne

    really? What methane engines does the RUssian have that is superior to Raptor?

  • Ignacio Rockwill

    Love the rapid progress on Raptor. I wish Blue would take a page out of the SpaceX book and trade their tortoise mascot for…well, anything really. Even a slightly faster tortoise would be a move toward goodness.

  • Ignacio Rockwill

    Can you share a source for this? I have to imagine this is at a very low TRL at SpaceX.

  • Steve

    Musk was advertising the fact that Raptor had surpassed the RD-180 in chamber pressure. It may be slightly more difficult to obtain the same chamber pressure using a less dense fuel, but that is not the subject of his comparison tweet. The Russians didn’t have the advantage of additive manufacturing to build precision parts, or any of the modern simulation tools for testing their design. The Russians should be proud of building such a wonderful engine family at that time. With all of the advantages that SpaceX has, you might ask, what took so long ? Are there really any lingering questions about how to build a staged combustion engine ? Really, the only SpaceX challenge is to build it cheaply. Going with a clean burning fuel like Methane only helps with re-use since you eliminate the coking problems of RP-1.

  • windbourne

    I’m sorry.
    I recall a recent article in which Gwen spoke about how hard it is to get nuke material when addressing that. However, I can not find that article.
    If I see it again, I will try to remember that it was you and post it.

  • Terry Stetler

    While Russia did build the first full flow stage combustion engine (RD-270) back in the 1960’s it was a far simpler beast (hypergolic) with a chamber pressure of 260 bar and ended up a hangar queen.