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Not very convincing. Citing a conclusion about cost from WW2 era Germany isn't a great argument. Every such product cost more in the distant past when prevail

Not very convincing. Citing a conclusion about cost from WW2 era Germany isn't a great argument. Every such product cost more in the distant past when prevailing techniques are only just barely feasible. Dyna-soar was a Space Plane; a human rated space vehicle. Yes it ultimately found no useful role and was shut down. There is little meaningful overlap between such a program and an unmanned missile system; the relevance of Dyna-soar is close to zero. Twice it is stated that hypersonic missiles have "few" advantages over cruise or ballistic technologies. But few isn't zero and the difference could be crucial. Doubtless the authors would love to credibly claim there are zero advantages, but they can't, because that is false. The implicit advice here is that we learn about the importance of these "few" advantages when they're applied to our forces by an opponent. We then end with the classic "pressing needs elsewhere" cop-out. "Pressing needs" are infinite. We seek value in our policies and investments and this writing fails to convince that hypersonic weapons have no value.

sandworm101 6y ago
>> There is little meaningful overlap between such a program and an unmanned missile system; the relevance of Dyna-soar is close to zero. Except that part of Dyna-soar was dipping back into atmosphere for plane change maneuvers. That dipping in and out of atmosphere to make course changes would seem very relevant to missiles. But this quote is more telling of the author: "Thus, while hypersonic weapons fly a more direct path to their targets, they lose much of their speed throughout flight, ultimately taking longer to reach their targets than comparable ballistic missiles." No. A ballistic missile follows a ballistic trajectory. That means it is on a very fixed schedule, a tight min/max flight time to the target based on predictable spheres-in-a-vacuum physics. A hypersonic missile on a lower trajectory can indeed get to some targets sooner. It will require more fuel/energy to do so, as opposed to following the higher ballistic path, but fuel efficiency isn't a big deal when you are delivering nukes.
- topspin 6y ago
  Sorry but citing technical similarities doesn't salvage the Dyna-soar argument for me. Dyna-soar program was a manned bomber/reconnaissance platform. The recent efforts of advanced nations centers on missile development. The lack of a mission for the former has nothing to do with the latter. The difference is so great that I feel the use of Dyna-soar in this context to be misleading, and that probably deliberate.
- cameldrv 6y ago
  There are a range of ballistic trajectories that can work. If you want to get there faster, you can use a shallower trajectory (they usually call this a depressed trajectory). This takes more energy, so you get a shorter range for a given missile. The other problem is that the warhead spends more time in the atmosphere. Most ballistic missiles use unguided reentry vehicles, so the best accuracy comes from a high trajectory that comes almost straight down onto the target, so it spends the least time interacting with the unpredictable atmosphere. However, if the reentry vehicle is guided, depressed trajectories become more practical. The U.S. did this in the past with the Pershing II, which had terminal radar guidance, and we have a half-way version of this with path length fusing on the Trident II, where the warhead is not guided, but the detonation point is controlled based on trajectory error. Russia has tested these in the past few years and could have deployed them. IMO it's an underappreciated threat because it could allow attacks against hard targets with less than 10 minutes of warning.
SiempreViernes 6y ago
> We seek value in our policies and investments and this writing fails to convince that hypersonic weapons have no value. So for defence spending you need not ask for "good value", you're willing to spend billions as long as zero value can credibly be denied? If they have great values, surely you could list some of them? After all you imply hypersonics have many, and dire advantages! Anyway, the article does mention some advantages (later detection by OTH radar and ability to perform some evasive manoeuvrers), and then explains why these do not provide outstanding benefits. I guess you found this bit lacking and wanted a mention of some of the many other unique qualities hypersonics have?
- topspin 6y ago
  > After all you imply hypersonics have many, and dire advantages! No such implication exists for my part. I made no mention of a budget figure. Please don't ascribe to me things which I did not write. I don't know if my legislature or military do or will find hypersonics worthy of billions. My point is that this writing did nothing to convince me that they aren't. > and then explains why these do not provide outstanding benefits I don't believe we can really know how hypersonics might be employed. Militaries have been punished for their lack of vision many times in history. Until we do know what is possible the examples given are straw men.
  - SiempreViernes 6y ago
    You seem hard to convince that money could go elsewhere, but perfectly fine to let it go to these projects on no particular basis at all. That's not actually a neutral stance, however much you avoid writing outright praise of hypersonic weapons. In in a small sense sense your last objection is of course almost trivially true for any weapon: each war uses them based on the experience of the last conflict, and armies are always finding novel ways to deploy them. However, if one takes a larger view it is demonstrably false: physics is not so unknown that these weapons could whatever they want, so to call the models used for the article so off the mark as to become straw men is simply wrong.
    - 6y ago
josefresco 6y ago
> Twice it is stated that hypersonic missiles have "few" advantages over cruise or ballistic technologies. But few isn't zero and the difference could be crucial. But isn't that the author's point? That these weapons are evolutionary, not revolutionary?
- topspin 6y ago
  Whether hypersonic weapons are evolutionary or revolutionary isn't presently knowable or based on any meaningful measurement. Cleverly written guesswork.
  - SiempreViernes 6y ago
    That argument works perfectly well both ways you know, meaning arguments in favour of their utility are equally speculative until we've had us a proper war.
    - topspin 6y ago
      Bad arguments aren't better than no arguments.

sandworm101 6y ago

>> There is little meaningful overlap between such a program and an unmanned missile system; the relevance of Dyna-soar is close to zero. Except that part of Dyna-soar was dipping back into atmosphere for plane change maneuvers. That dipping in and out of atmosphere to make course changes would seem very relevant to missiles. But this quote is more telling of the author: "Thus, while hypersonic weapons fly a more direct path to their targets, they lose much of their speed throughout flight, ultimately taking longer to reach their targets than comparable ballistic missiles." No. A ballistic missile follows a ballistic trajectory. That means it is on a very fixed schedule, a tight min/max flight time to the target based on predictable spheres-in-a-vacuum physics. A hypersonic missile on a lower trajectory can indeed get to some targets sooner. It will require more fuel/energy to do so, as opposed to following the higher ballistic path, but fuel efficiency isn't a big deal when you are delivering nukes.

topspin 6y ago
Sorry but citing technical similarities doesn't salvage the Dyna-soar argument for me. Dyna-soar program was a manned bomber/reconnaissance platform. The recent efforts of advanced nations centers on missile development. The lack of a mission for the former has nothing to do with the latter. The difference is so great that I feel the use of Dyna-soar in this context to be misleading, and that probably deliberate.
cameldrv 6y ago
There are a range of ballistic trajectories that can work. If you want to get there faster, you can use a shallower trajectory (they usually call this a depressed trajectory). This takes more energy, so you get a shorter range for a given missile. The other problem is that the warhead spends more time in the atmosphere. Most ballistic missiles use unguided reentry vehicles, so the best accuracy comes from a high trajectory that comes almost straight down onto the target, so it spends the least time interacting with the unpredictable atmosphere. However, if the reentry vehicle is guided, depressed trajectories become more practical. The U.S. did this in the past with the Pershing II, which had terminal radar guidance, and we have a half-way version of this with path length fusing on the Trident II, where the warhead is not guided, but the detonation point is controlled based on trajectory error. Russia has tested these in the past few years and could have deployed them. IMO it's an underappreciated threat because it could allow attacks against hard targets with less than 10 minutes of warning.

SiempreViernes 6y ago

> We seek value in our policies and investments and this writing fails to convince that hypersonic weapons have no value. So for defence spending you need not ask for "good value", you're willing to spend billions as long as zero value can credibly be denied? If they have great values, surely you could list some of them? After all you imply hypersonics have many, and dire advantages! Anyway, the article does mention some advantages (later detection by OTH radar and ability to perform some evasive manoeuvrers), and then explains why these do not provide outstanding benefits. I guess you found this bit lacking and wanted a mention of some of the many other unique qualities hypersonics have?

topspin 6y ago
> After all you imply hypersonics have many, and dire advantages! No such implication exists for my part. I made no mention of a budget figure. Please don't ascribe to me things which I did not write. I don't know if my legislature or military do or will find hypersonics worthy of billions. My point is that this writing did nothing to convince me that they aren't. > and then explains why these do not provide outstanding benefits I don't believe we can really know how hypersonics might be employed. Militaries have been punished for their lack of vision many times in history. Until we do know what is possible the examples given are straw men.
- SiempreViernes 6y ago
  You seem hard to convince that money could go elsewhere, but perfectly fine to let it go to these projects on no particular basis at all. That's not actually a neutral stance, however much you avoid writing outright praise of hypersonic weapons. In in a small sense sense your last objection is of course almost trivially true for any weapon: each war uses them based on the experience of the last conflict, and armies are always finding novel ways to deploy them. However, if one takes a larger view it is demonstrably false: physics is not so unknown that these weapons could whatever they want, so to call the models used for the article so off the mark as to become straw men is simply wrong.
  - 6y ago

josefresco 6y ago

> Twice it is stated that hypersonic missiles have "few" advantages over cruise or ballistic technologies. But few isn't zero and the difference could be crucial. But isn't that the author's point? That these weapons are evolutionary, not revolutionary?

topspin 6y ago
Whether hypersonic weapons are evolutionary or revolutionary isn't presently knowable or based on any meaningful measurement. Cleverly written guesswork.
- SiempreViernes 6y ago
  That argument works perfectly well both ways you know, meaning arguments in favour of their utility are equally speculative until we've had us a proper war.
  - topspin 6y ago
    Bad arguments aren't better than no arguments.