Jonathan_S wrote:From the Cataphract launches we've seen the 1st stage is launched at half power (180 second run time), while CM drives don't have a half power setting (that's one of the compromises that lets them achieve their higher acceleration compared to even the full accel of contemporary ship killer missiles). So they seem like they'd have to be at different power settings; thus counter to your other speculation.
Not necessarily. They are different missiles, with very different impellers and designed for different purposes. A CM has a massively overpowered wedge so it's big to broom and destroy regular missiles when operating in defensive mode. On the other hand, its ring is much smaller because the missile itself is a smaller body. So it's possible that a CM at full power is equivalent to a shipkiller at half power.
It's not likely, though. It would be just too convenient that they happened to match, even if there's an underlying physical reason why this power setting is a sweet spot (the fact that all the missiles in all navies have very similar accelerations would imply there is such a thing). Moreover, if it were the case, someone would have stumbled upon the solution previously.
Add to that one thing I forgot in the previous post: we know that the SLN (and the MAlign) did not have access to the technology of quantum baffles, which makes true MDMs possible. If they had had it at the time, they'd have been talking about true MDMs later, and not even wondering if a 3-stage MDM was possible. It seems the MAlign has developed a solution for that, for their next generation missiles codenamed Ninurta, but hasn't shared that with the SLN or TIY.
As Travis explained:
A Call to Duty, ch. 7 wrote:"Two impeller rings at such close proximity can't avoid bleeding control flickers and capillary fields between them. The fact that the secondary set isn't yet active doesn't matter—it'll still be misaligned when it does light up."
"Then you shield the second set," Cyrus bit out. "You put something between the two rings to keep that from happening."
"You can't, sir," Long insisted doggedly. "It's a quantum tunneling effect. No known material or counterfield can block or suppress it. You'd need a good hundred meters of distance between the rings, which would either require an acceleration-resistant pylon that's physically impossible to construct with any known material, or else a much thicker pillar that will jump the costs with every square centimeter of cross-section that you add. The missile would end up as big as a corvette and as expensive as a destroyer. Either way, it would not show up on sensors as a normal missile. Not the way it did in the simulation."
(
bold mine)
Lt. Cyrus had the right idea, but as Travis pointed out, the SLN and the MAlign would have access to no known material or field that could allow the activation of a second impeller
at all if it had interacted with the first. That means the power settings of the twain simply don't matter: they'd have had to be spaced far enough apart that the effects would be near zero.
In turn, that explains why no one else had built missiles like the Cataphract: too expensive, even if material sciences had improved to the point such a missile only cost as much as a frigate or courier instead of a destroyer. Only the SLN would have had the funds to contemplate such a thing, and even then only at a war-time emergency, because we know they couldn't support the expense rate for much longer.
Now in the books they talk at one point about a potential system defense variants of Apollo that would have a CM derived 4th drive.
No, it doesn't look like they are. Those (the Mk25) appear to be regular missiles like the Mk16 and Mk23, only with four rings instead of three. It appears that the powered range of a Mk23 at 65 million km is more than enough for ship-to-ship engagements, and that is much improved with Apollo anyway. The differences are the final velocity and the total travel time, which probably are of little value for ship-to-ship. So I think there's little reason for ships to carry even bigger missiles, and there are reasons not to, because being bigger they'd need bigger tubes to fire from and would have fewer missiles to fire, even from pods. It's a similar reason why BCs and CAs fire Mk16 from tubes, even though they can and did carry Mk23 in limpeted pods.
On the other hand, for system defence, you may want to strike a target that is very far very quickly. Plus, you do have sensor assets in the system that would help you guide the missile to target, something you can't count on for ship action in a hostile system.
We just don't know. Nor do we know if such a 4 drive system defense Apollo variant was ever finalized and deployed. (Obviously Mycroft relies on system defense pods of Apollo -- but it is unclear whether they have a 4th drive of any kind, much less this proposed CM derived one)
True, we haven't heard of the Mk25 being deployed. We haven't heard of any problems with it either, though absence of data is not data of absence. I just don't expect there to be problems shielding a fourth impeller ring: clearly going from one to two was the biggest breakthrough, but it could be that two was the limit if it required a wide enough separation that a 3-stage MDM was impractical even for SDs to fire. So I think that if you can shield three, then four shouldn't be a problem (you solve problems for "one, two, many").