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U.S. Air Force says it conducted successful hypersonic weapon test
- oneoff786 4y agoI believe most explosives detonate in the air anymore. Is there a speed threshold where the kinetic energy is enough to justify not doing that?
- kurupt213 4y agoThere are tank fired kinetic anti tank rounds. Depleted uranium darts are devastating. But to answer your question, I believe the energy released by a kinetic impactor quadruples every time you increment a Mach number. So a kinetic impact at Mach 4 is 16x more energetic than a mach 2 impact.
- djmips 4y agoI think there might be a grammar problem in your statement. What did you mean?
- oneoff786 4y agohttps://ygdp.yale.edu/phenomena/positive-anymore https://ygdp.yale.edu/phenomena/positive-anymore I picked it up from Pennsylvania unintentionally. Not a huge fan of it tbh.
- Buttons840 4y agoHe means how fast does a missile need to go so that the kinetic energy is greater than the chemical/explosive energy.
- jstanley 4y agoIt's relatively common to use "anymore" to mean "nowadays". I think it must have come from hearing things like "They don't do that any more" and not recognising "any" and "more" as separate words, but rather as a concept that just means "now", such that "They do that anymore" is equally valid.
- djmips 4y agoWow really? I missed out on that one. Thanks for the update.
- zmgsabst 4y agoNot really. Even for hypersonics, the efficiency of chemicals at storing energy and then releasing it is hard to beat. 1 kg of TNT produces 4.2MJ; to get the same energy in 1kg of projectile you’d need to travel at ~6500 miles per hour. (About mach 9 at sea level.) The role of hypersonics is in application: - sudden attacks, to prevent response - low altitude, high velocity attacks, to defeat intercept - penetration, coupled with a chemical warhead, to hit hardened targets Source: https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy) https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)
- theptip 4y agoAppreciate the detail. I'm not sure I see the conclusion as obvious though; if a 2kg weapon is going Mach 20 (as the weapon in the OP apparently does), with 1kg of that being TNT, then the explosives only provided 20% of the energy (rounding to the nearest 10% to make the example clearer). If you just lobbed the same 1kg weapon at Mach 20 then you'd have halved the weight, and reduced the energy to 40%. Presumably lower weight means easier to maneuver (more agile for intercepting or avoiding countermeasures, depending on what you're trying to hit). It seems like around Mach 10-20 is where the tradeoff could become non-obvious, depending on how much you value weighing less?
- zmgsabst 4y agoPer OP: > The U.S. Air Force said on Monday it had conducted a successful test of a hypersonic weapon, which flew at five times the speed of sound. But to your question: > around Mach 10-20 is where the tradeoff could become non-obvious, depending on how much you value weighing less? The same logic holds at mach 5-8 (ie current hypersonics), which is why they’re being developed: You want a weapon that can surprise, evade, or penetrate better — even if that’s less destructive overall.
- adrian_b 4y agoWhen close to the ground, something flying at Mach 10-20 would either be deccelerated very quickly to much lower speeds, if flying passively, or require a very large mass of fuel to maintain the speed. Moreover, it would be hard to avoid being partially vaporized before reaching the target. So hitting something at Mach 10-20 seems much more difficult than filling the missile with explosives and detonating it. Weapons based on kinetic energy alone seem practical only against satellites or against targets that fly in the upper atmosphere.
- michael1999 4y agoMany anti-air missiles detonate at range and destroy with shrapnel. And shrapnel damage is just kinetic. But that's probably not what you mean. Yes. For lightly armoured targets, their own velocity might do it. See https://en.wikipedia.org/wiki/Brilliant_Pebbles#Brilliant_Pebbles https://en.wikipedia.org/wiki/Brilliant_Pebbles#Brilliant_Pe... And if you want to go further, de-orbiting tungsten rods make the explosives redundant. https://en.wikipedia.org/wiki/Kinetic_bombardment https://en.wikipedia.org/wiki/Kinetic_bombardment
- robonerd 4y ago> de-orbiting tungsten rods Over-hyped I think. Sure the kinetic energy is incredible, but what of the terminal ballistics? I think these would have substantial over-penetration against anything except deep bunkers; most of that kinetic energy would be spent driving that rod through bedrock, like an APFSDS dart shot into tank armor. Good for punching holes in things.
- michael1999 4y agoCompletely agree. Those systems solve a bunch of non-problems and completely destabilize MAD. There's a reason they were never developed. But I wouldn't discount to the ability of weapons designers to figure out the frangibility and deliver the bulk of the energy to a tuneable depth.
- aidenn0 4y agoAbout mach 8, but then you need to actually hit your target. For ground based targets that's probably fine (in fact for slow-moving, armored targets kinetic-energy penetrators are already a thing). For anti-aircraft fire the goal is to get "close enough" that the explosives will damage it.
- hammock 4y agoLook up "rods from God." https://en.wikipedia.org/wiki/Kinetic_bombardment https://en.wikipedia.org/wiki/Kinetic_bombardment https://www.businessinsider.com/air-force-rods-from-god-kinetic-weapon-hit-with-nuclear-weapon-force-2017-9#:~:text=The%20%22rods%20from%20god%22%20idea,bunkers%20or%20secret%20underground%20sites https://www.businessinsider.com/air-force-rods-from-god-kine....
- mywittyname 4y agoIt always baffled me that these weren't named after Zeus.
- xatlasm 4y agoDrop a deuce from Zeus?
- nradov 4y ago"Rods from God" is a silly impractical sci-fi concept. It would be too expensive to launch a large enough satellite constellation to provide persistent global coverage. And the satellites themselves wouldn't be survivable. The prompt global strike mission can be accomplished more cheaply and effectively by missiles launched from aircraft or ships.
- greedo 4y agoWaiting for the F-35 haters to hijack this thread...
- FunnyBadger 4y agoThey've only been working on this since the 1980s without success. Just review copies of AW&ST from late 1980s.
- ortusdux 4y agoIt was an AGM-183 ARRW. The test on the 14th hit Mach 5, but they claim a theoretical top speed of Mach 20. https://en.wikipedia.org/wiki/AGM-183_ARRW https://en.wikipedia.org/wiki/AGM-183_ARRW
- deleted 4y ago[deleted]
- rootusrootus 4y agoReading through the timeline on that page, it sounds like Congress has decided to kill the project. I wonder if this successful test will turn that around.
- ortusdux 4y agoFrom Lockheed's press release: Additional booster and all-up-round test flights will continue throughout 2022, before reaching Early Operational Capability (EOC) in 2023. So it sounds like they found the cash somewhere. https://news.lockheedmartin.com/2022-05-17-us-air-force-and-lockheed-martin-successfully-complete-arrw-hypersonic-boosted-test-flight https://news.lockheedmartin.com/2022-05-17-us-air-force-and-...
- riku_iki 4y agoIt says they transferred half of funds from procurement to R&D, probably because previous tests failures.
- KennyBlanken 4y agoBiden's bumping up the military budget by tens of billions of dollars, that's what's turning this around. We finally got ourselves out of the Middle East, but we gotta keep the military-industrial complex fed, I guess. We already spend more total and per capita than the next top ten countries combined. It's so sad. We could do so much domestically, or just worked on influencing foreign policy by helping other countries, instead of military force projection.
- 4y ago
- nathanyz 4y agoProbably just us flexing that we have them too. Likely have had them, but kept it quiet as no need to declare our capabilities. Since others are crowing about it, just letting them know we also have same.
- jaywalk 4y agoAbsolutely. I also don't believe that they "only" go 5x the speed of sound. That's most likely just the speed they're willing to disclose, and the actual speed is classified.
- Zandikar 4y agoI mean, our X-15 was a manned hypersonic aircraft (by a good margin of the minimum 5x speed) in the 1960's, and ICBM's have been guided unmanned long range hypersonic munitions since a similar era, just to name a few. We have plenty of experience with hypersonics, and we almost certainly have continued research and experimentation into the field. The real technological linchpin isn't so much the speed, but would be things like guidance, precision and manuevering at those speeds, or perhaps other things like stealth, heat management materials (lot of friction from the air when you're ripping through it at those speeds), transatmospheric flight, advancements in hybrid (sc)ramjet engines, etc. Going hypersonic in and of itself is nothing new. We've been doing that since the 60's. Shit we made a manhole cover go hypersonic before the Russian's ever launched sputnik. It's what something can do after its moving at hypersonic speed that's of real consequence.
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- rib3ye 4y agoYes, but only because our Congress is trying to make political theater of the topic. https://www.youtube.com/watch?v=qz_2r6rWgY8 https://www.youtube.com/watch?v=qz_2r6rWgY8
- sandworm101 4y ago>> "Following separation from the aircraft, the ARRW's booster ignited and burned for expected duration, achieving hypersonic speeds five times greater than the speed of sound," it said. Big deal. The booster is just a rocket. And Mach numbers are meaningless without altitude reference. Anything that travels to the outer atmosphere/space will hit extreme Mach numbers on the way up/down. So without any further data the above statement means little more than "we fired a big rocket". Did the sustainment motor, the air-breathing thing that differentiates a true hypersonic from every other rocket, did that motor function in cruise mode? Or is this essentially just a boost-glide ballistic missile?
- nilstycho 4y agoThe ARRW boost-glide vehicle is unpowered, but maneuverable. This test used a dummy boost-glide vehicle, though. They haven't disclosed if releasing the dummy vehicle was part of this test, and if so whether it succeeded. This test was just testing the boost phase. edit: From the Lockheed Martin press release (https://news.lockheedmartin.com/2022-05-17-us-air-force-and-lockheed-martin-successfully-complete-arrw-hypersonic-boosted-test-flight https://news.lockheedmartin.com/2022-05-17-us-air-force-and-...): > The successful flight demonstrates the weapon’s ability to reach and withstand operational hypersonic speeds, collect crucial data for use in further flight tests, and validate safe separation from the aircraft to deliver the glide body and warhead to designated targets from significant standoff distances. … Additional booster and all-up-round test flights will continue throughout 2022, before reaching Early Operational Capability (EOC) in 2023.
- cersa8 4y agoHow much of this is hype and boasting about military advances. According to this article hypersonic missiles are far from practical https://www.scientificamerican.com/article/the-physics-and-hype-of-hypersonic-weapons/ https://www.scientificamerican.com/article/the-physics-and-h...
- zozin 4y agoThey are. Chinese and Russian “advances” in hypersonics are pure marketing. The US was testing scramjets in the 1960s. The US has a hypersonic space plane. Alas, the media fell for it and billions are now being spent on “catching up” with our “peer” competitors.
- robonerd 4y agoAll ballistic missile reentry vehicles are hypersonic too. Talk of "hypersonic" without specifying the technology and actual capabilities is quite silly. Presumably hypersonic cruise missiles is implicit context.. but I don't believe the general public understands that and the media is doing a generally terrible job of communicating it.
- ramesh31 4y ago>All ballistic missile reentry vehicles are hypersonic too Sure, but ballistic trajectories are trivially interceptible. It's not just about speed. The new arms race is with hypersonic glide vehicles that are capable of maneuvering all the way to the target at mach 8+. With that, the weapon becomes impossible to intercept with any existing technology.
- hungryforcodes 4y agoExisting. Soon to be found.
- robonerd 4y agoMy money is still on Aegis BMD intercepting the missile during the terminal phase. Hypersonic glide-boost weapons are mainly for avoiding mid-course interception. When you're going hypersonic, 'maneuverable' is relative; the turning radius is quite huge and such missiles will be easy for Aegis to track during the terminal phase.
- staunch 4y agoMy understanding is that Russia and China are building hypersonic glide missile so they can penetrate any US missile defense system, which the US doesn't really even have. And neither does Russia or China have an effective missile defense system that the US needs the capability to defeat. So it seems like an arms race without either side really having advanced to the point of necessitating a further step. Then again, I suppose it makes sense to be one step ahead of where the game is going. Or is there something more to this?
- HWR_14 4y agoI imagine the use case is more conventional weapons, for example taking out a navy flagship.
- Buttons840 4y agoBetter we try to one up each other with fast cruise missiles than with more nukes. In fact, nukes are useless now, let's just get rid of all of them. (wink wink)
- coding123 4y agoNukes simply existing may have saved more lives at this point. That could, of course, change in seconds at any time.
- manachar 4y agoYou joke about nukes, but since they're such an "unthinkable" weapon they've become almost useless for most people who have them. You need them so that others with fewer compunctions are not able to steamroll you, but as an actual help to the kinds of conflicts currently going on and likely to happen in the future, they're just not as effective. Whether that's fast cruise missiles, more powerful drones, more disposable drones, robot warriors, cyber-warfare, etc. militaries are trying to find the technology that breaks the stalemate caused by MADD.
- aidenn0 4y agoAsk Putin about how useless having nukes is for preventing NATO involvement in the Ukraine...
- elEpHantiaSis 4y ago[flagged]
- Vladimof 4y agoCan't be that hard to make an hyper-sonic weapon when some planes are able to go hyper-sonic... you could use a plane as a weapon if it was anyways. My laser gun is hyper-sonic too....
- nradov 4y agoThere are no manned hypersonic (Mach 5+) aircraft. Since the retirement of the SR-71, nothing can sustain a speed much over Mach 2.4.
- pyinstallwoes 4y agoIn terms of public information. How long has an aircraft maintained secrecy from public that was used militarily?
- RickJWagner 4y ago