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On MDM Flight Profiles

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Re: On MDM Flight Profiles
Post by Fireflair   » Sat Jul 29, 2017 11:50 pm

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Effectively within a system with Mycroft deployed, I would submit that Apollo has no control range limits. Multiple installations around the system are standard with the Mycroft design.

As for detection range, we know shipboard sensors are far more limited than any kilometers large stationary array. I did a quick search and couldn't find the detection range for an impeller driven missile, though I'm sure some one has it. There are limits to the range of that detection. Just as there are limits on seeing ship's impellers.

If you look back at HoQ, the FTL drones were key to her success at curving inside the Thunder of God. She couldn't use shipboard sensors to see ToG, but her drones and the FTL transmissions let her keep inside the other ship's course.

So while I don't know what the detection range is for an active impeller, it seems quite conceivable that missiles could be launched from the other side of the solar system to intercept some one without their being aware of that missile launch.
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Re: On MDM Flight Profiles
Post by Weird Harold   » Sun Jul 30, 2017 1:22 am

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Fireflair wrote:So while I don't know what the detection range is for an active impeller, it seems quite conceivable that missiles could be launched from the other side of the solar system to intercept some one without their being aware of that missile launch.


Not to mention the minor detail that an attacking force would have to actually be looking in the right direction to detect missile drives on the far side of the Hyper-limit.

There would be limits to the range even with Mycroft, though. IIRC, there is a seven minute delay from the MWHJ to Landing City even with FTL relays. Missiles would take several hours to travel the same distance. A battle could be over with long before the missiles arrive.
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Re: On MDM Flight Profiles
Post by Jonathan_S   » Sun Jul 30, 2017 9:54 am

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Weird Harold wrote:
Fireflair wrote:So while I don't know what the detection range is for an active impeller, it seems quite conceivable that missiles could be launched from the other side of the solar system to intercept some one without their being aware of that missile launch.


Not to mention the minor detail that an attacking force would have to actually be looking in the right direction to detect missile drives on the far side of the Hyper-limit.

There would be limits to the range even with Mycroft, though. IIRC, there is a seven minute delay from the MWHJ to Landing City even with FTL relays. Missiles would take several hours to travel the same distance. A battle could be over with long before the missiles arrive.

My assumption is that it's not worth shooting at, or providing relays to shoot at, targets much beyond the hyper limit. (With your main system defense pods - obviously things like Blackbird yards or terminus forts will have their own defensive pods to use against attackers) Too much chance they can just hyper out.

With Mycroft relays every 5 or so light minutes throughout the inner system (so missiles are never beyond Apollo range of the nearest relay) you can easily engage a target at the far hyper limit - call it about 45 lightminute transmission path[1]. That actually gives, assuming each relay adds negligible delay, less control lag than a conventional MDM at max powered range.

45 lightminutes has about a 43.5 second FTL transmission time (one way), equivalent to normal MDM at 43.5 lightseconds - 13,071,000 km (which is 1/5 it's powered range)

So a fort orbiting Manticore could trivially, through relays, engage any target inside the hyper limit - and from a transmission lag perspective far beyond - but they you've got to worry about wasting your launch if they hyper out on you.

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[1] Manticore orbits ll.5 lm from it's star, hyper limit is at 22.0 km, and I assumed there would be a sphere of Mycroft relays 5 lm inside Manticore's orbit and you'd have to bounce the signal partway round the star.
If you assume the innermost rlay sphere is at Manticore's orbital distance then that adds a few lm to the transmission path.
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Re: On MDM Flight Profiles
Post by Weird Harold   » Sun Jul 30, 2017 10:33 am

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Jonathan_S wrote:So a fort orbiting Manticore could trivially, through relays, engage any target inside the hyper limit - and from a transmission lag perspective far beyond - but they you've got to worry about wasting your launch if they hyper out on you.


If you've got the budget to seed you hyper-limit with Mycroft platforms as close as you propose, you still have to deal with the physical transit times of the missiles. Any missiles close enough to have acceptable run times to the target are going to be close enough for the target to detect their drives as soon as they light off.

That means you need to seed your system with a lot of pods so your attack doesn't need to come from planetary orbit or across the hyper-limit. You also need a dispersed missile deployment to minimize the "proximity kill" danger. Dispersing your missiles requires a LOT more missiles to mount an effective launch against a large attack force.

How much defense will your budget buy?
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Re: On MDM Flight Profiles
Post by Jonathan_S   » Sun Jul 30, 2017 11:39 am

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Weird Harold wrote:
Jonathan_S wrote:So a fort orbiting Manticore could trivially, through relays, engage any target inside the hyper limit - and from a transmission lag perspective far beyond - but they you've got to worry about wasting your launch if they hyper out on you.


If you've got the budget to seed you hyper-limit with Mycroft platforms as close as you propose, you still have to deal with the physical transit times of the missiles. Any missiles close enough to have acceptable run times to the target are going to be close enough for the target to detect their drives as soon as they light off.

That means you need to seed your system with a lot of pods so your attack doesn't need to come from planetary orbit or across the hyper-limit. You also need a dispersed missile deployment to minimize the "proximity kill" danger. Dispersing your missiles requires a LOT more missiles to mount an effective launch against a large attack force.

How much defense will your budget buy?

The entire are inside Manticore's hyper limit is 4/3*pi*(22 lm)^3 basically 44,602 lm^3. A relay capable of covering 5 lm covers 523.5 lm^3 = you need about 85 to theoretically cover it - even allowing for packing issues and redundancy you're should be looking at less than 100 Mycroft relays to saturate the area inside the hyper limit.

Now even with Manticore's 4 drive system defense missiles it'd be a long ass flight to launch from Manticoran orbit against somebody on the far side of the system - about an hour to cover the 45 lightminutes. I wouldn't suggest it, though if you did do that launch on an enemy that had come 30 minutes into the system (liekly 8 million km or so) they wouldn't be able to escape before getting hit. But even minor allies, in the pre-Apollo era, were getting perimeter pod emplacements, so the missiles will likely launch from much closer than the command node controlling them as to be. (I think with the old style perimeter arrays the perimeter LAC bases were providing the fire control - with Mycroft you'd only need unmanned relays out there and the people and tactical section controlling the missiles could be many light minutes away - deep inside the hyper limit.

But even so you'd distribute the fire control origin points - though in Manticore you could theoretically have enough redundancy if the whole system could be run from orbital forts around either Manticore or Sphinx. But it probably makes sense to put another fort or two spread around deep in the inner system.

Overall adding 100 or so FTL relays doesn't seem to make the system substantially more expensive than that they were already installing at places like Zanzibar - much less what must be in place already at Manticore.
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Re: On MDM Flight Profiles
Post by Jonathan_S   » Sun Jul 30, 2017 11:52 am

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Jonathan_S wrote:The entire are inside Manticore's hyper limit is 4/3*pi*(22 lm)^3 basically 44,602 lm^3. A relay capable of covering 5 lm covers 523.5 lm^3 = you need about 85 to theoretically cover it - even allowing for packing issues and redundancy you're should be looking at less than 100 Mycroft relays to saturate the area inside the hyper limit.
Heh, I don't think I was entirely awake while working on that post - it took about 3 tries to get this right (1st thoughtlessly did just a circle, then accidentally did the surface area of a sphere before finally doing area of a sphere)

Also, if you economized and only did a spherical shell between Manticore (11.5 lm) and the hyper limit (22 lm) you'd reduce the volume to cover somewhat (14%) and drop the relays needed to cover it down to 73.
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Re: On MDM Flight Profiles
Post by Fireflair   » Sun Jul 30, 2017 11:10 pm

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What's the transit time from the hyper limit to the planet? Depends on the star and the planet involved, but it's not minutes. It's hours. Mycroft controlled missiles could be in motion as soon as you're sure of the threat, from outside the detectable range of the attackers. More over missiles accelerate to their max velocity pretty quickly, so their time to cross the distance is much shorter than the star ships you're mobilizing.

At the same time you can be getting your mobile assets spun up and headed out. You've got a couple hours till you encounter the enemy forces but a quick bit of math will tell you when to launch other missiles to support the mobile forces.

Shoot, you might be even able to hide the initial missile fire from the orbit near the planet behind the active wedges of your mobile forces, getting your missiles on their way and into ballistic flight early enough that the enemy won't have a chance to track them.
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Re: On MDM Flight Profiles
Post by Somtaaw   » Mon Jul 31, 2017 2:40 am

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Late to the party, but I think you need to recalculate and get some options where the final drive is High setting.

Stages 1 & 2 would be impacting the general velocity needed, but Stage 3 set to maximum allows the missiles well over 96,000 gravities for dodging, on top of whatever they have from the pre-ballistic stage. Which is what I think gives a slightly superior attack profile, without sacrificing evasive potential within the effective envelop.


Assuming LLL or LLH is when you're making the ridiculously long-ranged "you must have Apollo for this" type shots, such as the very very end of BoMa when Honor forced Tourville to stand down. And even then, she later admits even with Apollo, that was beyond effective range (at that time anyways).
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Re: On MDM Flight Profiles
Post by Jonathan_S   » Mon Jul 31, 2017 9:34 am

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Somtaaw wrote:Late to the party, but I think you need to recalculate and get some options where the final drive is High setting.

Stages 1 & 2 would be impacting the general velocity needed, but Stage 3 set to maximum allows the missiles well over 96,000 gravities for dodging, on top of whatever they have from the pre-ballistic stage. Which is what I think gives a slightly superior attack profile, without sacrificing evasive potential within the effective envelop.


Assuming LLL or LLH is when you're making the ridiculously long-ranged "you must have Apollo for this" type shots, such as the very very end of BoMa when Honor forced Tourville to stand down. And even then, she later admits even with Apollo, that was beyond effective range (at that time anyways).


I only bothered to calculate out to 71 million km because past that every profile is coasting and they've achieved their final ranking (low-low-low give you the lowest time to target - because the final stage can start it's attack run so much further out than low-low-high).

71 million km is only 3.1 lightminutes. It's true that under light speed control people tend to want to engage at around 55 million km but this isn't that extreme a shot - it'd be low probability w/o Apollo but not insanely so.

3.1 lightminutes appears to be well within normal Apollo range - it's true that at Solon it was only used at 3 lm but in Michelle's simulation in SftS it had at least 4.4 lm range.
In contrast Honor's ultra long-shot during the BoM was 8 lm!, 143,900,380 km, which is beyond its unrelayed range.


Anyway, the graphs do include every option where the final drive was set to high, but with the exception of the shortest range snap shot, where all 3 drives were set to high that flight profile too longer to get to target than having the fina drive set to half power - so it didn't get listing out below the graphs because I only listed the fastest of the 8 possible profiles for each range.

(But did acknowledge that sometimes tactical considerations might cause a captain to select a slower profile; but didn't specifically mention reserving 92,000 gees for terminal maneuvering as one of those)
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Re: On MDM Flight Profiles
Post by Jonathan_S   » Mon Jul 31, 2017 10:04 am

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Fireflair wrote:What's the transit time from the hyper limit to the planet? Depends on the star and the planet involved, but it's not minutes. It's hours. Mycroft controlled missiles could be in motion as soon as you're sure of the threat, from outside the detectable range of the attackers. More over missiles accelerate to their max velocity pretty quickly, so their time to cross the distance is much shorter than the star ships you're mobilizing.
[Edit: Theemile pointed out I slipped a decimal point and had to drastically revise the post's numbers downwads
As you say it depends on star and planet involved, but I thought I'd do some quick number crunching on our star system of Manticore.

Manticore orbits its star at 11.5 lm
Sphinx orbits at 21.2 LM
Hyper Limit is 22.0 LM

This is a fast as possible approach, so drop down to the Alpha bands, work up the the full 0.6c to carry as much velocity as possible over the hyper limit, and a zero safety margin emergency right on the hyper limit. I'll assume a fleet acceleration of 500 gees (which is way quicker than SLN SDs though way slower than RMN ones). Oh and we'll go for a high-speed flyby, not a zero-zero intercept.

In the alpha bands 0.6c (179875 km/s), drop to n-space and suffer the 92% velocity drop. Base velocity 14,390 km/s.
Sphinx is 0.8 lm (14,390,000 km) away
Manticore is 10.5 lm (188,870,000 km) away

From the base velocity, at 500 gees, it will take:
14 minutes 30 seconds to reach Sphinx
105 minutes 21 seconds (about 1.7 hours) to reach Manticore

Now if you were just interested in getting within 45,000,000 km to have a pretty solid MDM shot at orbital infrastructure Sphinx is already in range and Manticore is "just" 87:49 away
Last edited by Jonathan_S on Mon Jul 31, 2017 11:13 am, edited 1 time in total.
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