Is it just me or has the Pentagon and the complex largely replaced the word "soldier" with "warfighter"? Feel like I've seen it a lot lately and I'm not sure what the change implies
Well for one US citizens might have to quarter warfighters.
DARPA's hypersonic scramjet achieves successful flight
91–100 of 212 posts
Re: DARPA's hypersonic scramjet achieves successful flight
#92Earlier quoted context omitted.
And the SR-71 is so simple the complexity falls off a cliff at the engine, hence your inclination to only care about that in comparing the two. The space shuttle is like a reusable mobile space station, airlocks and all. Occupants of the SR-71 wore space suits the entire time, there's a lot of minimalism on display in the SR-71 which is a large part of what makes it so glorious.
The SR-71 was very complex. For example it had multiple heat exchangers to get rid of heat, to transfer it to the fuel before it was combusted. The titanium structure was complex to maintain. Welding needed to be done in "bubble" work stations under protective gas.
> The titanium structure was complex to maintain. Welding needed to be done in "bubble" work stations under protective gas
Operational complexity is orthogonal, and tends to be inversely proportional to simplicity in implementation...
For instance they needed to refuel the thing immediately upon reaching operating temperature in flight, since it leaked like a sieve on the runway until everything expanded. Rather than try fix that somehow with more engineering, they shifted the complexity into operations.
IIRC it couldn't even start its own engines cold, relying instead on hot-rod v8s setup on the runway to bootstrap the thing. More operational complexity in favor of leaving an entire subsystem out of the plane.
Don't get me wrong, I'm a huge fan of the SR-71, but so much of that appreciation stems from its ruthless pursuit of its narrow operational goals, for as much what it isn't as it is.
It's the polar opposite of stuff like the space shuttle or F-35 where the aggregate complexity is through the roof to accommodate a kitchen sink.
Re: DARPA's hypersonic scramjet achieves successful flight
#93Earlier quoted context omitted.
Not quite sure why interceptor missiles would have to "fly fast enough to catch up" unless you're shooting at a missile departing from you (that is to say, unless you actually have to catch up with something).
You don’t always have missile interceptors on the target land. Aegis is a mobile platform that can be deployed anywhere, and being overflown is a real possibility. For example, your missile defense platform might be off the coast several km, and the target to intercept flies over it aiming for the land behind it. In this scenario, any interceptor launched from that platform would have to “catch up.”
No, it would just have to reach the target interception area in time. That's not quite the same as "catching up", although of course the possible radius within which this area must be located shrinks as a function of speed ratios.
And if by "flies over it", you meant the defense system as "it", that's still effectively point defense. Although this particular situation is unlikely for obvious reasons; the chance that your defense system would be exactly below the flight path of a missile while not being its target is small.
Re: DARPA's hypersonic scramjet achieves successful flight
#94For a moment, reading only the first paragraph, I was hopeful that the problem of accelerating from subsonic to hypersonic had been solved. Alas, further down it makes clear that a booster was involved. Presumably a small solid rocket that accelerates to Mach 3-5(?) prior to scramjet ignition. Fine for a weapons system but will never be useful as transportation. Is anyone aware of progress toward being able to reach…
Unless you're trying to go to space, there really isn't much reason to go this fast in the first place. Even relatively modest supersonic passenger flight has proven to be a commercial failure (good luck to Boom Tech inc... you guys will need it.)
If you're going to space, an SSTO with scramjets would be interesting. But I think if SpaceX's reusable Starship succeeds without that tech, it would be hard to justify the additional complexity and expense of an SSTO built with a class of engine which hardly exists at all right now.
Re: DARPA's hypersonic scramjet achieves successful flight
#95I don't understand the purpose of having a missile that fast.
Re: DARPA's hypersonic scramjet achieves successful flight
#96Is it just me or has the Pentagon and the complex largely replaced the word "soldier" with "warfighter"? Feel like I've seen it a lot lately and I'm not sure what the change implies
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Re: DARPA's hypersonic scramjet achieves successful flight
#97Is it just me or has the Pentagon and the complex largely replaced the word "soldier" with "warfighter"? Feel like I've seen it a lot lately and I'm not sure what the change implies
It simply means that marines, sailors, etc get bent out of shape when you call them "soldiers." In their lingo, soldiers are in the Army.
In common parlance, a 'soldier' is anybody who is part of a military and an 'army' is any and all military. But I would not expect the Pentagon to be so casual with their use of terms relating directly to their affairs.
Re: DARPA's hypersonic scramjet achieves successful flight
#98Re: DARPA's hypersonic scramjet achieves successful flight
#99I don't understand the purpose of having a missile that fast.
More speed = more difficult to both intercept and detect (less response time).
Not sure what the commercial applications would be though.
Re: DARPA's hypersonic scramjet achieves successful flight
#100I don't understand the purpose of having a missile that fast.
Nothing can shoot it down (yet).