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Here is the video which they should have put in the post: https://global.honda/content/dam/site/global-en/topics-new/cq_img/2025/c_2025-06-17ceng/print/c_2025-
by 3ds 1y ago
Here is the video which they should have put in the post:
https://global.honda/content/dam/site/global-en/topics-new/cq_img/2025/c_2025-06-17ceng/print/c_2025-06-17c_101H.mp4 https://global.honda/content/dam/site/global-en/topics-new/c...
- djaychela 1y agoFor some reason the landing of that reminded me of the Eagle from Space:1999 - there was something different in the ballistics of it compared to SpaceX and Blue Origin. Fantastic to see, thanks for the video link.
- darrelld 1y agoI'm accustomed to seeing large plumes of chemicals coming out the other end in my minds eye when I think about rocket launches. This looks "clean" coming out the exhaust. Why is that? Is it due to the nature of chemicals it uses?
- fogh1 1y agoBasically yes, other rockets might burn chemicals that create more soot. This one seemingly doesn’t.
- nine_k 1y agoSoot means carbon-rich fuel, like RP1, and a very fuel-rich mix. Most launches I ever saw had basically zero soot, and a clean exhaust of a well-balanced fuel / oxidizer mix. Military rockets, and solid-fuel boosters like the kind the Shuttles used to use, indeed produce very visible exhaust, because they use heavy fuels, and sometimes heavier oxidizers, like nitric acid. This is because they need to be in the fueled state for a long time, ready to launch in seconds; this excludes more efficient but finicky cryogenic fuels used by large commercial rockets. The large plumes that you usually see the first few seconds when a rocket is blasting off a launch pad are mostly water vapor. The launch pad would be destroyed by the exhaust were it not cooled during the launch by large amounts of water, which gets evaporated instead of the concrete.
- hyperbrainer 1y agoThe water also serves the purpose of reducing reflecting acoustic energy.
- ggreer 1y agoSeveral reasons. It's filmed in daylight, so any flame or exhaust will be less visible. The rocket engine is much smaller than anything that would go on an orbital booster, so there's less exhaust than what'd you see for an orbital launch. Also it's looks like it's a hydrolox rocket (using liquid hydrogen and oxygen as fuel), which has the least visible flame. The combustion product is almost entirely water vapor. Methalox (methane + liquid oxygen) is the next cleanest, which emits water, CO2, and a little bit of soot. Kerolox (RP-1 and oxygen) is the most common propellant used today, and it emits a significant amount of soot. Solid boosters put out the most visible exhaust, as burning APCP[1] emits solid particles of metal oxides. Also some rockets (mostly Russian, Chinese, and Indian) use unsymmetrical dimethylhydrazine + dinitrogen tetroxide, which emits a reddish-orange exhaust. Both compounds are toxic, as is the exhaust. 1. https://en.wikipedia.org/wiki/Ammonium_perchlorate_composite_propellant https://en.wikipedia.org/wiki/Ammonium_perchlorate_composite...
- perihelions 1y agoI doubt it's hydrogen, because the color looks off (blue, rather than pink), and because it'd be a poor fit for a small R&D project. They're not optimizing for performance-at-all-costs on this. Ethanol/oxygen is my guess. Blue, and also very little soot.
- lupusreal 1y agoProbably methalox I think. It's the trendy prop mix most reusable programs are settling on because it doesn't coke up engines like kerosene and is easier to model in computers, and doesn't cause metallurgical problems like hydrogen while being much more dense. Alcohol isn't impossible but seems unlikely to me because that's not what you'd want for the full scale rocket they're presumably working towards.
- ggreer 1y agoHydrogen engines aren't always pink. The exhaust color depends on the ratio of oxidizer to fuel. The Space Shuttle's main engines were hydrolox, but their exhaust had almost no pink/red. It's hard to say for sure, but I lean towards Honda's rocket using hydrogen. Honda has experience with it. They use hydrogen in their fuel cell vehicles, and their press release from 2021 mentions using hydrogen for rockets.[1] I'm pretty sure both fuel and oxidizer are cryogenic, because when the rocket lands it vents from several areas (most likely separate tanks). That would rule out ethanol or methanol as the fuel. I don't see any secondary exhaust from a gas generator, and staged combustion would be something to brag about (and much higher thrust), so my guess is that it's an expander cycle. Expander cycle engines require a fuel that boils easily, so it would have to be fueled by propane, methane, or hydrogen. I don't think it's propane, as the only propane/lox rocket I've seen has orange exhaust.[2] If Honda poached some engineers from Mitsubishi, I could see them going with a hydrolox expander cycle, as that's what the H family of rockets use. The only thing that doesn't line up with hydrogen is the low thrust given the propellant consumption. Based on the claimed wet/dry mass (1,312kg/900kg), they used at most 412kg of propellant. Flight duration was 56.6 seconds, so that's an average of 7.28kg of propellant per second. If the stated wet/dry mass is correct and the rocket used up all of its fuel, then the rocket's thrust was around 13kN at the start and around 7kN near the end. Let's say it averaged 10kN. Force equals mass flow rate times exhaust velocity. So 10kN divided by 7.28kg/sec is 1.374 km/s. Divide by standard Earth gravity and you get 140 seconds, which is pathetic for a rocket. It could be that they only used a small fraction of the available propellant, or they had a poor nozzle design, or the engine was throttled very low and was therefore less efficient. If we assume the test flight only used 40% of the available propellant, then we'd get a flow rate of 2.9kg/sec and a specific impulse of 352 seconds. But that sort of assumption can be used to come up with any Isp. Still, I think it's using either hydrogen or methane as fuel. Nothing else fits with the video. 1. https://global.honda/en/newsroom/news/2021/c210930beng.html https://global.honda/en/newsroom/news/2021/c210930beng.html 2. Here's a video of Isar Aerospace's Spectrum rocket, which uses propane/lox: https://x.com/isaraerospace/status/1906418985173758236 https://x.com/isaraerospace/status/1906418985173758236
- numpad0 1y agoMost civilian rockets have solid strap-on boosters(actual technical term) that emit the signature thick white smokes, as well as leave contrails at high speeds. Neither would be visible for non-solid rockets at low speeds.
- whitehexagon 1y agoGreat clean video link thanks, but I cant work out the scale, first it looks like a toy rocket, then from the distance shot it looks huge, like spaceX huge, and then landing it looks quite small again, especially with the lawn sprinklers. But an impressively smooth landing regardless, and I would imagine maybe harder the smaller the rocket is.
- tw04 1y ago> successfully landed its 6.3-metre (20.6-foot) experimental reusable launch vehicle From another article.
- hbrav 1y agoOr in natural units: three very tall men stood on top of one another, wearing a top hat.
- TeMPOraL 1y agoIt's not a rocket, but three men in a trench coat?
- lowestprimate 1y agoHow many bananas?
- peterlada 1y agoAnd under the French cost is an African swallow.
- ryandrake 1y agoOh jeez, how many football fields is that?
- Someone 1y agoLet’s see. 2 cm of grass on top of, say, 10 cm of earth would make the height of a football field 12cm. That would make it as high as about 50 football fields.
- api_or_ipa 1y agoWatching the video, when the rocket lifted-off, it stood on a couple small risers. When it landed, the risers were gone. Did someone run out there and grab them?
- Kye 1y agoI think the landing spot is different from where it took off from. The trees in the landing shot weren't there in the takeoff shot.
- sprkv5 1y agothe lift off spot is at the edge of the launch pad, whereas the landing spot is at the center of the launch pad. [edit] the camera angle and the camera height from the ground is different as well between the lift off and landing.
- Kye 1y agoTaking another look, I see four little rectangles that seem to match the risers close to the camera at the landing, but far from the rocket. I think they may have actually retracted. That would be neat. It makes more sense than someone going out and grabbing them during the short flight. Those things would need to be sturdy and attached to not melt or blow away during the launch, and they would be hot. edit: If you open up the first image on the submission and look to the left of the crane, you can see what look like the risers. They do seem to come out of the ground. You can see the same trees as the landing shot. edit: I didn't realize the page had more videos under the Download button. I was wrong about the rectangles, but you can definitely see it's landing in a different spot in the onboard video (#3). You can still see the risers when it lands.
- pavel_lishin 1y agoIt may not have landed on the same pad it took off from.
- feoren 1y agoDespite the other comments, the landing spot is clearly the same as where it took off. Take a screenshot at 0:09 and one at 0:48 and you can see that it's most certainly the same pad. The camera has moved slightly to the left on the landing, that's all. Someone must have run out and grabbed the risers.
- mbowcut2 1y agoIt's interesting how I couldn't tell whether the rocket was 1m tall or 10m tall in this video. Turns out it's actually 6m tall per the link.
- gessha 1y agoJapan continuing their legacy of minituriazing everything they develop. \s
- sciencesama 1y agoYou need some manga
- ethbr1 1y agoThey play at either extreme. https://thegaijinghost.com/blog/japan-life-sized-gundam-through-years https://thegaijinghost.com/blog/japan-life-sized-gundam-thro...
- viewtransform 1y agoBonsai rockets.
- jagged-chisel 1y agoIn the first shot on the pad, I thought “oh, it’s a slightly oversized model rocket” and then when it cut I realized it was quite a bit bigger.
- neodypsis 1y agoWhat is the steam cloud for after landing?
- 420official 1y agoIt's liquid propellant being vented, the fuel is under extreme pressure so when its released it immediately expands to a gas. I don't know that Honda has said what their propellant is, but it's probably liquid hydrogen and liquid oxygen.
- deleted 1y ago[deleted]
- vFunct 1y agoThe feet landing extension reminds me of the Delta Clipper DC-X rocket, the first reusable VTOL rocket from 30+ years ago: https://www.youtube.com/watch?v=wv9n9Casp1o https://www.youtube.com/watch?v=wv9n9Casp1o I wonder if that's the optimal design for VTOL rocket landers? Or is that more particular to smaller lighter rockets and eventually you need heavier duty options for bigger rockets? Also the DC-X was eventually intended to be single-stage-to-orbit (SSTO). Do any of these reusable rockets plan on being SSTO? Whether from Space-X/Blue Origin or this or the Chinese ones? SSTO is where you're going to dramatically change the economics of rockets, as you now only have to worry about refueling when launching satellites, instead of using an expendable second stage..
- almosthere 1y agoThey should have totally had a Civic in the background and a guy mowing the lawn near the sprinkler.
- bozhark 1y agoGenerational engine ad Needs some F1
- bee_rider 1y agoHondas at least used to (I haven’t kept up) have that great cheap/reliable car reputation… “the Honda of rockets” has a good ring to it I think, haha.
- zharknado 1y ago“Sure, your rocket’s reusable, but can it go 300k miles on the original engine?”
- perilunar 1y ago300k miles is only about 12 low earth orbits, so easily achievable by a second stage booster (though it’s going to be coasting for most of it). Not so easy for a booster though.
- bee_rider 1y agoReally once the rocket is in space, the joke kinda falls apart; frictionless vacuum and all that.
- blt 1y agoAwaiting the rocket engine equivalent of the K20.
- hajhatten 1y agoThey still are, they're still references in durability/quality for motorcycles as well (together with the other Japanese manufacturers).
- wiseowise 1y agoAmazing. Looks like cartoons I saw when I was a child, expect now it is in real life. Surreal.
- redbell 1y agoFrom the second 22 to 44, I really couldn't tell if the rocket is ascending or descending :) Also, I believe it would have been a historical moment if they filmed the entire staff watching the event from the control room.
- Aeolun 1y agoThey can’t put the video first. This is Japan. First have to strongly declaim how safe they were being with a 6m rocket.
- ChuckMcM 1y agoAgreed, it brings the story home. What I most like about this news is that Honda has joined Blue Origin and SpaceX in demonstrating a complete "hop" (all though my all time favorite is the "ring of fire" video SpaceX did.) But it also illustrates that I've seen in the Bay Area time and time again, which is that once you demonstrate that something is doable (as SpaceX has) It opens the way for other capital to create competitive systems. At Google, where I worked for a few years, it was interesting to see how Google's understanding of search (publicly disclosed), and the infrastructure to host it (kept secret) kept it comfortably ahead of competitors until the design space was exhausted. At which point Google stopped moving forward and everyone else asymptotically approached their level of understanding and mastery. I see the same thing happening to SpaceX. As other firms master the art of the reusable booster, SpaceX's grasp on the launch services market weakens. Just as Google's grasp of the search market weakens. Or Sun's grasp of the server market weakened. When it becomes possible to buy launch services from another vendor which are comparable (not necessarily cheaper, just comparable) without the baggage of the damage Elon has done, SpaceX will be in a tougher spot. It also helps me to understand just how much SpaceX needs Starship in order to stay on top of the market. Some folks will no doubt see this as casting shade on SpaceX, I assure you it is not. What SpaceX's engineering teams have accomplished remains amazing and they deserve their success. It is just someone who has been through a number of technology curves noting how similar the they play out over their lifetimes. Having witnessed first hand how DEC felt that Sun's "toy computers" would never eclipse DEC in the Server business, and watched as United Launch Alliance dismissed Falcon 9 as something that would never seriously challenge their capabilities, it feels almost prophetic to watch SpaceX's competitors emerge.
- ChrisMarshallNY 1y agoDon't forget Ballmer dissing the iPad. I also won't forget the marketing department at the camera company I worked at, dismissing the iPhone, when it first came out (it ended up eating their lunch).
- josh2600 1y agoI always think about blackberry’s internal design teams telling the ceo that the iPhone was fake, then getting one and seeing that it was a small logic board with a giant battery. RIM got so completely smoked with their ten year development cycles. It’s amazing if that they still have a business today to be honest.
- duxup 1y agoSuch a smooth takeoff and landing all by by itself. I remember watching old sci-fi shows and the rocket would do that and I always thought "that doesn't make any sense". Now it does.
- LargoLasskhyfv 1y agoShould have cleaned the lens of the first cam. Second cam cutting in at about 50 seconds in was perfect.
- vzaliva 1y agoThis video is so much like in the old black and white sci-fi movies!
- dumdedum123 1y agoAw. It didn't even do a "real" hop. The engines stayed on all the time. For the first real hop see Xombie circa 2010.