17 ms·
Full ignition for ESA’s reusable rocket engine
- cgeier 3y agoQuestion for the space nerds: how impressive is this?
- ericd 3y agoAccording to the wikipedia article ( https://en.wikipedia.org/wiki/Prometheus_(rocket_engine) https://en.wikipedia.org/wiki/Prometheus_(rocket_engine) ), they're aiming for 3-5 reuses, which I believe is significantly fewer than SpaceX's Falcon 9 engine, Merlin. But maybe they'll get more in practice. It's a methalox/methane-oxygen engine, like SpaceX's Raptor, as opposed to RP-1 kerosene, like Merlin. One nice aspect of this is that methalox doesn't deposit so much soot on the inside of the engine, so reuse should be simpler (this is one of the reasons for SpaceX's newer Raptor engines also using methalox). It's got an open gas generator cycle, which means that it's likely less efficient than SpaceX's full-flow staged combustion Raptors, since it means it loses a few percent of its fuel to just running the turbopumps and the exhaust spitting off the side, rather than than heading down into the combustion chamber. It sounds like it's much cheaper to build vs. their last generation of engine, but we'll see how it ends up in practice. Getting something like this working is impressive, but who knows if it will end up being competitive, SpaceX is still iterating really quickly. Not an expert, but the design feels a little dated already, in comparison in comparison to Raptor, and Raptor is already flying.
- frederikvs 3y agoI'd say it's pretty impressive. Building and igniting a rocket engine is hard. For more detail, I can recommend watching "Why starting a rocket engine is so hard" by Tim Dodd [0]. It's not "never been done before" impressive, they're a few years behind e.g. SpaceX's Raptor engine, which uses the same propellants, and is also reusable. But still, a new rocket engine is no small feat - the engine is probably the hardest part of a rocket. This is quite literally rocket science. [0] https://www.youtube.com/watch?v=bAUVCn_jw5I https://www.youtube.com/watch?v=bAUVCn_jw5I
- chroma 3y agoThey're more than a few years behind SpaceX. SpaceX reached a similar milestone back in 2016, when they test fired a subscale Raptor engine[1] that produced 1 meganewton (~100Tf) of thrust.[2] By 2019, they'd tested their full size Raptor at 1.5 meganewtons (172Tf) of thrust.[3] The current production version of Raptor produces 2 meganewtons (225Tf)[4]. SpaceX has successfully tested a newer version of Raptor that produced 2.4MN (269Tf) for 45 seconds.[5] 1. https://twitter.com/elonmusk/status/780275236922994688 https://twitter.com/elonmusk/status/780275236922994688 2. "With a thrust of 1MN (225klbf) at sea level, this was to be the first methane full flow engine to ever reach a test stand." https://www.nasaspaceflight.com/2016/10/its-propulsion-evolution-raptor-engine/ https://www.nasaspaceflight.com/2016/10/its-propulsion-evolu... 3. https://twitter.com/elonmusk/status/1093424663269523456 https://twitter.com/elonmusk/status/1093424663269523456 4. https://twitter.com/elonmusk/status/1295498964205068289 https://twitter.com/elonmusk/status/1295498964205068289 5. https://twitter.com/elonmusk/status/1657249739925258240 https://twitter.com/elonmusk/status/1657249739925258240
- panick21_ 3y agoThis European engine is comparable to Merlin, not Raptor.
- breput 3y agoPositives: * Uses liquid methane and oxygen for fuel, which is far easier to work with than the current Vulcain hydrogen/oxygen fueled engine and burns cleaner than kerosene/oxygen engines, which is better for reusability. * This is an engine that might work well on a small to medium reusable launcher, which ESA no longer has access to after their Vega rocket repeatedly failed and they lost access to Russia's Soyuz rockets[0]. * ESA is at least trying to do reusability after dismissing the idea for years. Negatives: * "100-tonne thrust class" is half the thrust of either SpaceX's Raptor or Blue Origin's BE-4 engines, which will be similarly reusable and using the same fuels. * Additive layer manufacturing sounds cool but I'm not sure it has any real benefits over conventional engine manufacturing techniques. SpaceX is reportedly close to building one Raptor engine _per day_ without 3D printing. * They are undecided on the fuel ("A version using liquid hydrogen-liquid oxygen is also being developed."). That is an entirely different engine and ground support infrastructure, but they are presumably doing it so it could be used directly in the Ariane 6 rocket? * Arianespace/ESA is at least a decade[1] behind SpaceX in reusability and due to rocket failures and retirements, and the delays with Ariane 6, won't have _any_ flying rockets until 2024. So they are far behind and do not have a good track record with speedy development. [0] https://spacenews.com/europe-grappling-with-space-access-challenges/ https://spacenews.com/europe-grappling-with-space-access-cha... [1] https://www.space.com/europe-no-reusable-rocket-until-2030s https://www.space.com/europe-no-reusable-rocket-until-2030s
- mezeek 3y agoAdditive layer manufacturing has major benefits... unless you want to have a super-high production rate like Raptor. So it's a positive for them.
- frederikvs 3y agoESA really needs to work on how they present this kind of thing. Igniting a brand new rocket engine is a sensational event - I would have expected at least a video of the full 12 second burn, from a good viewpoint. Ideally from multiple camera angles. But we just get one still image, taken from what looks like the worst position. ESA is doing really cool stuff, but they're doing a bad job of convincing people that they're doing cool stuff.
- booi 3y agothis is definitely something SpaceX does right. Even the most mundane launches is a multi-hour professional production with high quality cameras in multiple angles.. even when the thing explodes it feels like it went well.
- palata 3y ago> this is definitely something SpaceX does right. To me (european), I don't like how SpaceX shows off. The technology is cool though, but when I see their kind of communication, to me it sounds like "US marketing". So yeah... cultural thing maybe.
- Aeolun 3y agoOn the balance, I much prefer having the stream to not having it. I can always turn the sound/commentary off.
- reaperducer 3y agoI don't think of it as showing off. I think of it as documenting for posterity. We're at an inflection point when it comes to space exploration. Ar this rate, future generations will have days of video and documentation of the accomplishments in America, and a footnote along the lines of "Europe did some things, too. Visit the sub-basement of a library in an office building in Paris for more information."
- palata 3y ago
- semessier 3y agovery impressive and competitive - if it were 2010 Note that the Raptor 3 is at 269 tons thrust (vis-à-vis 100 tons) and 350 bar chamber pressure (with 100 bar for the Prometheus). The raptor is state-of-the-art full-flow staged combustion which is described as very tricky, Prometheus dated open-cycle. Raptor has been extensively tested and refined for years now and is getting very close to real flight heritage. Once Prometheus has flight models the Raptor will be at least a decade ahead, probably continuing to move rapidly. Taking a guess Raptor is probably much cheaper to produce and operate than Prometheus. It appears like a failed design by plan similar to a decision to continue expendable Arianes provided that 'there are only 10 or so launches per year' and implicitly that the system is set up to produce throw-away rockets that need lots of resources to produce each example.
- sottol 3y agoThis is clearly geo-strategic. Also never hurts to have competition, see eg Amazon or Google what happens when the innovator becomes a monopoly.
- martin8412 3y agoThe goal of ESA is to have independent space capabilities.
- panick21_ 3y agoWell actually their STATED GOAL was to be highly competitive in the international launch market as well. When Ariane 6 was greenlit there was much talk about that this investment needed to be made to be competitive and so on and so on. And of course now 10 years later its all like 'all we wanted is independent space access'. Of course if that was the case just flying Ariane 5 would have been better. Not having 3 different rockets would have been better.
- trompetenaccoun 3y agoAnd sadly they're behind even China at this point, which is a bit of a joke if we're honest. ESA is a perfect example for what a bureaucratic monster Europe is these days. With a similar budget as CNSA but no clear vision and goals, the funds have mostly been wasted in recent years. They have the engineers, a good spaceport, the knowledge, etc... everything they'd need. But the stagnating political culture is holding them back. The US went through something similar, but at least with the private spaceflight boom the Americans seem to have snapped out of it.
- deleted 3y ago[deleted]
- Proven 3y ago[dead]
- deleted 3y ago[deleted]
- causality0 3y agotesting will continue at the end of 2023 at the German aerospace agency DLR’s test site in Lampoldshausen, Germany. Uh, so what are they spending the next six months doing?
- AlgorithmicTime 3y ago[dead]
- martin8412 3y agoPreparations for test flight of Ariane 6.
- panick21_ 3y agoIts certainty an interesting engine but for a very advanced space program, as they Europeans want to be, it isn't anything ground breaking. If some US startup would announce something like this everybody would shrug and call it par for the course and not particularly innovative. Europe has never developed first stage close cycle engine. The Soviets have mastered close cycle engines as far back as the 60s and even today (at least until the Ukraine war) great Russian/Ukrainian engine were for sale. And today many even startups are working on close cycle engines. This engine is another open cycle engine while the world for real competitive launch vehicles is moving to more advanced engines. And those that do not, are not doing it because they want their next generation rocket to be there as soon as possible. While a European rocket with this engine is at least a decade or more out. It is targeted at being reusable and that is good of course but pretty much every modern engine program is gone be restartable and reusable. We don't have much information how many times it will be reusable, what its startup mechanism and we just generally don't have that much information. So the thing that's kind of stunning here is that Esa/Arianespace is developing this one next generation engine and keep hyping it and building it up as this next generation engine for Europe. But its really nothing special, there are many engines in development (some much further along) in the US that are just gone be as advanced or more advanced. ESA here looks more like a random startup, rather being a leader in technology: Relativity Space Aeon-R: https://www.youtube.com/watch?v=W91fO97WAPo https://www.youtube.com/watch?v=W91fO97WAPo https://www.relativityspace.com/terran-r https://www.relativityspace.com/terran-r RocketLab Archimedes: https://en.wikipedia.org/wiki/Archimedes_(rocket_engine) https://en.wikipedia.org/wiki/Archimedes_(rocket_engine) Or how about Launcher E-2: https://www.youtube.com/watch?v=Th1mP0bU9L8 https://www.youtube.com/watch?v=Th1mP0bU9L8 https://launcherspace.squarespace.com/engine-2 https://launcherspace.squarespace.com/engine-2 Ursa Major: https://www.ursamajor.com/engines/arroway https://www.ursamajor.com/engines/arroway SpaceX Raptor 3: https://youtu.be/h_5ltDjun3g?t=72 https://youtu.be/h_5ltDjun3g?t=72 BlueOrigin BE-4: https://www.youtube.com/watch?v=hdS4azOaF2M https://www.youtube.com/watch?v=hdS4azOaF2M There are more that we could mention. So Europe hear is more like a small fish in a big pond. And compared to efforts like Raptor, this is many generations behind. This is not big ambition from Europe, but doing the bare minimum to have something that is somewhat modern. But by the time they will get it into a launch vehicle it will look old compare to the competition. The problem is that engine development in Europe is just very slow, and integrating engines to rockets is even slower. Consider the fancy new Vinci Upper Stage engine. It has been in development for over 20 years now, and will likely be 25 year of total time from start of development to first flight. And the worst of it is, the Ariane 6 Upper Stage mass is so heavy that Vinci amazing performance is held back by a terrible structural design. So even as they have this advanced engine, they resulting rocket isn't really great. ESA has a very, very long way ahead if they want their rocket to be more then just launcher military launches from its member states.
- Nocturium 3y ago[flagged]
- gigatexal 3y agoProps to Elon and SpaceX for lighting a fire under an entire industry; I don’t think there’d be much work in reusable rockets without their work. As I understand it the industry wrote them off. But SpaceX proved it was doable or at least made it sexy. Same with electric cars. For whatever reason the Tesla marque was so strong and the cars marketed so well and were decent enough it gave all the incumbents the gumption to make even larger more bet-the-company investments in EVs. Say what you will about Elon as a person and his running of Twitter (horrible) but he sure knows how to be a marketer and to stick-to-his-guns.
- martin8412 3y ago[flagged]