Topic Actions

Topic Search

Who is online

Users browsing this forum: No registered users and 11 guests

Fall 1924: What will the Admiralty build next

Join us in talking discussing all things Honor, including (but not limited to) tactics, favorite characters, and book discussions.
Re: Fall 1924: What will the Admiralty build next
Post by Jonathan_S   » Sun Jun 26, 2022 2:40 pm

Jonathan_S
Fleet Admiral

Posts: 7769
Joined: Fri Jun 24, 2011 2:01 pm
Location: Virginia, USA

Coming back to the Hermes Buoy acceleration at Mobius (without redoing all the deep background) I wanted to try put some bounds on it.


* The lowest possible acceleration would be assuming it's on a high-speed flyby, never even tried to slow down, and was released (at 9,440 KPS) the moment the idea was raised. And thus it only just reached 40,000 km from the SLN ships as communication was started.
In that case it needs to cover 137,960,000 km in 2h 1m.
That would require 269.9g

Now this seems unlikely as the person who identified it broadcasting from 40,000 km would likely have mentioned if it was sailing past at about 0.1c (28,603 KPS) -- but it does put a minimum floor on the acceleration.

* If it was released later, or is assumed to have less residual velocity then it would need more acceleration; but how much would depend on your assumptions about both flight time and residual velocity.

* I'd worked out that if it was released immediately but aimed for a zero/zero intercept at 40,000 km, just at the moment of the call, then it would seem to need approximately 825.25g of constant acceleration.

* Unfortunately, without knowing when it arrived it's not possible to calculate a particularly useful maximum ceiling on its acceleration. About the best we can do is to assume a constant acceleration and that it wouldn't crack RFC's 0.9c "speed limit" for anything in normal space.
That would give it a maximum accel of 53,800 gravities, with a total flight time of 16m 45.5s and a peak velocity of 269,783 KPS.
Which seems ludicrous. (And that it would be hanging around on station for nearly two hours before being used)

* And, of course, if we assume it coasted at 0.9c then its acceleration could be nearly unbounded; the higher the accel the greater percentage of the flight would be coast phase.



Still I'd guess it's much closer to the 825 number, maybe 1,000 - 2000g, than either of the more extreme bounds.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Somtaaw   » Sun Jun 26, 2022 5:22 pm

Somtaaw
Rear Admiral

Posts: 1109
Joined: Mon Sep 01, 2014 11:36 am
Location: Canada

Jonathan_S wrote:* Unfortunately, without knowing when it arrived it's not possible to calculate a particularly useful maximum ceiling on its acceleration. About the best we can do is to assume a constant acceleration and that it wouldn't crack RFC's 0.9c "speed limit" for anything in normal space.
That would give it a maximum accel of 53,800 gravities, with a total flight time of 16m 45.5s and a peak velocity of 269,783 KPS.
Which seems ludicrous. (And that it would be hanging around on station for nearly two hours before being used)

-snip-

Still I'd guess it's much closer to the 825 number, maybe 1,000 - 2000g, than either of the more extreme bounds.



Well by Helen's original plan, it was specifically to mindfuck the Sollies by NOT opening communications until practically the last second and still being beyond 'normal' communications range. But using FTL anyway to prove a point that they'd have been dead for over an hour had Terekhov intended to kill them.

That makes the hanging around on station near the Sollies for potentially two hours (well closer to 1h45m by my guess) was by deliberate intent and not any form of employing maximum possible speeds. So I concur that while the absolute maximum attainable speed is a bit ludicrous, especially since there's the whole 'undetected until it started broadcasting' thing which can't happen if it attained too high a velocity and started generating a bow shock effect.

However I think your estimate of only 1000-2000 gravs is considerably low though. Hermes Buoys were after all primarily intended for rapidly relaying FTL comms for Manticoran and now Grand Fleet units. So while I don't think they're capable of full Ghost Rider RD speeds with 20,000 gravs or more, I do think the Hermes Buoy is probably closer to 10,000 for a max, possibly as high as 15.

With a 10k grav acceleration, they can hustle around even a star system in a real hurry without remotely sacrificing their stealth. This would enable 2 (or more) widely separated Grand Fleet elements to stay in constant FTL communication with the Buoys acting as relay stations and changing positions as necessary to maximize transmission speeds.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Jonathan_S   » Sun Jun 26, 2022 6:46 pm

Jonathan_S
Fleet Admiral

Posts: 7769
Joined: Fri Jun 24, 2011 2:01 pm
Location: Virginia, USA

Somtaaw wrote:
Jonathan_S wrote:* Unfortunately, without knowing when it arrived it's not possible to calculate a particularly useful maximum ceiling on its acceleration. About the best we can do is to assume a constant acceleration and that it wouldn't crack RFC's 0.9c "speed limit" for anything in normal space.
That would give it a maximum accel of 53,800 gravities, with a total flight time of 16m 45.5s and a peak velocity of 269,783 KPS.
Which seems ludicrous. (And that it would be hanging around on station for nearly two hours before being used)

-snip-

Still I'd guess it's much closer to the 825 number, maybe 1,000 - 2000g, than either of the more extreme bounds.



Well by Helen's original plan, it was specifically to mindfuck the Sollies by NOT opening communications until practically the last second and still being beyond 'normal' communications range. But using FTL anyway to prove a point that they'd have been dead for over an hour had Terekhov intended to kill them.

That makes the hanging around on station near the Sollies for potentially two hours (well closer to 1h45m by my guess) was by deliberate intent and not any form of employing maximum possible speeds. So I concur that while the absolute maximum attainable speed is a bit ludicrous, especially since there's the whole 'undetected until it started broadcasting' thing which can't happen if it attained too high a velocity and started generating a bow shock effect.

However I think your estimate of only 1000-2000 gravs is considerably low though. Hermes Buoys were after all primarily intended for rapidly relaying FTL comms for Manticoran and now Grand Fleet units. So while I don't think they're capable of full Ghost Rider RD speeds with 20,000 gravs or more, I do think the Hermes Buoy is probably closer to 10,000 for a max, possibly as high as 15.

With a 10k grav acceleration, they can hustle around even a star system in a real hurry without remotely sacrificing their stealth. This would enable 2 (or more) widely separated Grand Fleet elements to stay in constant FTL communication with the Buoys acting as relay stations and changing positions as necessary to maximize transmission speeds.

As a counterpoint - normal Hermes Buoys are supposed to be just that; buoys. Anchored in place so they're at the correct intervals to relay messages from one to another. There's apparently a chain of them forming a link between the Junction and Manticore.
So the ones more permanently deployed in systems need long endurance, but barely more than station keeping drives.

And that was their original purpose - to relay FTL comms around friendly star systems.

Now ships do have (smaller? shorter endurance?, lower bandwidth?) deployable versions of the Hermes Buoy, but I still don't think they're really designed for the kind of use you mentioned.

Otherwise why would UH tell use that Forkaer and Hemphill are looking to strap them to Ghost Rider drone to provide FLT telemetry links to Agamemnons. If the Hermes buoy could self deploy at 10 - 15,000 gees, and a Ghost Rider (seems to) top out at 20k it'd hardly be worth the effort to strap them on.

And even a couple thousand gees self-deployment speed still lets you start up a real time conversation in a new system far sooner than you'd be able to by moving into real-time radio range. (And if you do need them to get there faster, for some reason, then Bolthole's solution appears to be to strap them onto a quicker GR drone :D)

But we just don't know for sure.
So with that I guess we can just wait as see if more data point, or an outright infodump, appears in a future book.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Somtaaw   » Sun Jun 26, 2022 9:29 pm

Somtaaw
Rear Admiral

Posts: 1109
Joined: Mon Sep 01, 2014 11:36 am
Location: Canada

Jonathan_S wrote:Otherwise why would UH tell use that Forkaer and Hemphill are looking to strap them to Ghost Rider drone to provide FLT telemetry links to Agamemnons. If the Hermes buoy could self deploy at 10 - 15,000 gees, and a Ghost Rider (seems to) top out at 20k it'd hardly be worth the effort to strap them on.

And even a couple thousand gees self-deployment speed still lets you start up a real time conversation in a new system far sooner than you'd be able to by moving into real-time radio range. (And if you do need them to get there faster, for some reason, then Bolthole's solution appears to be to strap them onto a quicker GR drone :D)


Unfortunately in a lot of the 'GA vs Solly' or 'GA vs MAlign' combat is being driven by plot and therefore inconsistent to normal operating patterns.

Sometimes the Hermes Buoys are deploying at apparently rapid speed, and other times they're slow as molasses, depending on what plot reasons dictate is necessary.

The other massive inconsistency is their use (sometimes) for fire control, and not other times. Maybe the Hermes Buoys that Bolthole is eventually/already producing are that higher bandwidth model that is both slow but capable of fire control? While the ones we see Terekhov, Henke and others employing for mindfuckery is a high-speed but low-bandwidth model only good enough for ship-to-ship video links?


So we'll definitely need a datadump or the like to establish some consistency, or explain what we're obviously missing about the drones.
Top
Re: Fall 1924: What will the Admiralty build next
Post by ThinksMarkedly   » Sun Jun 26, 2022 9:52 pm

ThinksMarkedly
Fleet Admiral

Posts: 3363
Joined: Sat Aug 17, 2019 11:39 am

Jonathan_S wrote:* The lowest possible acceleration would be assuming it's on a high-speed flyby, never even tried to slow down, and was released (at 9,440 KPS) the moment the idea was raised. And thus it only just reached 40,000 km from the SLN ships as communication was started.
In that case it needs to cover 137,960,000 km in 2h 1m.
That would require 269.9g


This one makes no sense and can be discarded. If the buoys have lower acceleration than the ships, then they wouldn't be used in the first place. The ships would overtake the buoys the moment they're launched if they are launched in the acceleration phase. If they were launched in the deceleration phase, then they wouldn't decelerate in the first place; they'd simply fly ballistically.

* I'd worked out that if it was released immediately but aimed for a zero/zero intercept at 40,000 km, just at the moment of the call, then it would seem to need approximately 825.25g of constant acceleration.


This one sounds unlikely too. Not as unlikely as the one above, but still. That's barely above the acceleration of a LAC or DD with the latest compensators. On your typical 12 light-minute hyperlimit-to-planet zero/zero, an 825-gravity buoy would arrive at the destination just over half an hour before the ships pulling 568 gravities. And a force that was limited by the acceleration of a Saganami-C (726 gravities) would arrive just over 11 minutes after the buoys.

More importantly, the fleet at 568 gravities would be 41 light-seconds from the planet when the buoys arrived; 5.5 light-seconds for the Sag-C force.

This means such buoys would be of very limited tactical value.

* Unfortunately, without knowing when it arrived it's not possible to calculate a particularly useful maximum ceiling on its acceleration. About the best we can do is to assume a constant acceleration and that it wouldn't crack RFC's 0.9c "speed limit" for anything in normal space.
That would give it a maximum accel of 53,800 gravities, with a total flight time of 16m 45.5s and a peak velocity of 269,783 KPS.


It can just go ballistically at whatever top speed the vehicles can sustain with their particle shielding and not compromising the stealth. I expect the latter to be the limiting factor, so they probably wouldn't crack 0.6c
Top
Re: Fall 1924: What will the Admiralty build next
Post by Somtaaw   » Mon Jun 27, 2022 4:02 pm

Somtaaw
Rear Admiral

Posts: 1109
Joined: Mon Sep 01, 2014 11:36 am
Location: Canada

ThinksMarkedly wrote:This one makes no sense and can be discarded. If the buoys have lower acceleration than the ships, then they wouldn't be used in the first place. The ships would overtake the buoys the moment they're launched if they are launched in the acceleration phase. If they were launched in the deceleration phase, then they wouldn't decelerate in the first place; they'd simply fly ballistically.


That's a good point, pushes Hermes drones up to a minimum of a 1000 gravs, so even LAC's wouldn't be slowed down by having a Hermes along for the longer-range communication link.

Zavala used a Hermes Buoy to speak with Commodore Dubroskaya in Saltash, and her battlecruisers were underway unlike most other uses in the Solarian War to speak with stations or planets.
Vice Admiral Dubroskaya’s battlecruisers accelerated towards the oncoming Manticoran destroyers at 3.89 KPS squared, eighty percent of their maximum theoretical rate of acceleration. There was no particular hurry, and even at that low accel, they’d move over four million kilometers closer to the Manties before Zavala’s twenty-seven-minute time limit expired.


Datums here:
  • 9 light-minute hyperlimit and where Zavala translated down
  • "their initial velocity was nine hundred and twenty-six kilometers per second, and they’re up to just over thirty-two hundred now. That means they’re accelerating at five-point-six KPS squared"
  • unspecified time Ghost Riders had already swept the system and caught the 4 battlecruisers doggo, and 3 destroyers at the far end of the system behind a moon
  • 30 minutes after detecting, confirmed battlecruisers to be Indfatiguables
  • 85 minutes in system, destroyers’ velocity relative to the system primary was up to 29,400 KPS, and they were barely three minutes from their turnover for a zero/zero intercept with the planet of Cinnamon, still over 88,000,000 kilometers ahead of them. They were also well inside the twelve-light-hour limit where they were supposed to have announced their identities.
  • still prior to turnover point, Zavala opened communications with Dueñas and used a Hermes that was never mentioned as to where, but presumably in orbit of Cinnamon, but makes the above 27 minute promise to open fire
  • "...the four Indefatigable-class battlecruisers currently approximately five thousand three hundred kilometers this side of Shona Station..." (key note: Shona Station is directly in orbit of Cinnamon, so call it planet orbit either way)
  • "The decision is yours, Governor. In either case, my ships will be in orbit around Cinnamon in approximately one and a half hours. Whether or not any of your warships are still intact at that time is up to you. Good day" - this was still JUST prior to Zavala's turnover so he's pretty close to his turn and starting to decelerate for Saltash orbit
  • three minutes later, as the battlecruisers’ nodes went fully online and a quartet of impeller wedges appeared on the tactical display and began moving away from their original position between Shona Station and DesRon 301
  • no mention whether it's the same Hermes or a new one, but somewhere within the next 10 minutes, shortly before Zavala's 27 minute timelimit expires, Zavala opens a channel with the Sollies

So boiling those datums down, is there were 2 uses of a Hermes and it's spaced out. It had to fly from 9 light-minutes to the planet and decelerate to zero, and then assuming it was the same one turn around and zip off after the Solly battlecruisers who were 5300 km away and moving less than 3 minutes after the call ended and pace their 396.7g acceleration back towards Zavala.


To account for future upgrades without needing to redesign the Hermes all the time, it would be a safe bet that Hemphill originally had it designed for 2000 gravity acceleration. Then because she's both a Geek and a Tactical Officer, she probably doubled that just for unforeseen tech advancement or tactical needs for approximately 4000 gravities. And I still think that's still on the extreme low end for a WAG.
Top
Re: Fall 1924: What will the Admiralty build next
Post by ThinksMarkedly   » Mon Jun 27, 2022 4:51 pm

ThinksMarkedly
Fleet Admiral

Posts: 3363
Joined: Sat Aug 17, 2019 11:39 am

Somtaaw wrote:"their initial velocity was nine hundred and twenty-six kilometers per second, and they’re up to just over thirty-two hundred now. That means they’re accelerating at five-point-six KPS squared"


Zavala's force was 5 identical Rolands, so that's pretty low. He should be able to easily pull 7 km/s².

However, he may have been holding his acceleration down because:

unspecified time Ghost Riders had already swept the system and caught the 4 battlecruisers doggo, and 3 destroyers at the far end of the system behind a moon


He wanted to get a good look at what was in the system before committing.

"...the four Indefatigable-class battlecruisers currently approximately five thousand three hundred kilometers this side of Shona Station..." (key note: Shona Station is directly in orbit of Cinnamon, so call it planet orbit either way)


That was pretty stupid of Dubroskaya. In 85 minutes since translation, it would require a drone only 1300 gravities to make the distance of 9 light-minutes on a 0.42c high-speed pass, or 2600 for zero-zero. I'd bet Solarian drones could achieve that, so hiding 5300 km from the objective of the incoming force is not hiding at all. In the same time, she could have put 12 million km between her and the planet at only 100 gravities, which she should have considered stealthy enough given her estimation of Solarian and Manticoran capabilities.

"Hiding in plain sight" doesn't work that way.

no mention whether it's the same Hermes or a new one, but somewhere within the next 10 minutes, shortly before Zavala's 27 minute timelimit expires, Zavala opens a channel with the Sollies


In 10 minutes at 3.89 km/s², Dubroskaya's forces would have only moved 700,000 km. The 2⅓ second one-way lag is probably acceptable for communication, even assuming that buoy didn't move to follow those ships and split the difference.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Jonathan_S   » Mon Jun 27, 2022 5:25 pm

Jonathan_S
Fleet Admiral

Posts: 7769
Joined: Fri Jun 24, 2011 2:01 pm
Location: Virginia, USA

Somtaaw wrote:Datums here:
  • unspecified time Ghost Riders had already swept the system and caught the 4 battlecruisers doggo, and 3 destroyers at the far end of the system behind a moon

Irrelevant nitpick.
It was Cinnamon’s moon the 3 DDs were hiding behind - so that puts them pretty clearly on the same end of the system as everybody else. :D

The moon is presumably within a million km (Earth's is only 1/4 of that) of the planet, and thus to both its Shona Station and the 4 BCs stationed 5,300 km above that. That's right next door on the scale of a solar system.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Somtaaw   » Mon Jun 27, 2022 5:30 pm

Somtaaw
Rear Admiral

Posts: 1109
Joined: Mon Sep 01, 2014 11:36 am
Location: Canada

I wrote the positions of the battlecruisers and planet orbits because I'd originally thought Shona station and Cinnamon were in different orbits, I double-checked before hitting submit just in case.

Tbh, I believe while they may be called 'Buoys' which would imply a general level of not-moving (ever), the Hermes are actually built on the Ghost Rider drone platform itself. By sharing the same casing, impellers and FTL units, that simplified manufacturing and meant all Hemphill had to do was design a different set of insides for mildly different purposes.

The full-up RDs dedicate most of their mass towards their highly sensitive sensors and only a portion towards the reactor because they were never intended for long-term missions. While the Hermes communications would flip that to be mostly reactor tonnage to enable much lengthier operational time because they don't need much sensors to track a ship or enter orbit of a planet/station.
Top
Re: Fall 1924: What will the Admiralty build next
Post by Somtaaw   » Mon Jun 27, 2022 5:46 pm

Somtaaw
Rear Admiral

Posts: 1109
Joined: Mon Sep 01, 2014 11:36 am
Location: Canada

Jonathan_S wrote:
Somtaaw wrote:Datums here:
  • unspecified time Ghost Riders had already swept the system and caught the 4 battlecruisers doggo, and 3 destroyers at the far end of the system behind a moon

Irrelevant nitpick.
It was Cinnamon’s moon the 3 DDs were hiding behind - so that puts them pretty clearly on the same end of the system as everybody else. :D

The moon is presumably within a million km (Earth's is only 1/4 of that) of the planet, and thus to both its Shona Station and the 4 BCs stationed 5,300 km above that. That's right next door on the scale of a solar system.


:lol: My bad, I was more skimming for any mentioning about Ghost Rider Drones, Hermes drones, Shona Station, the battlecruisers (and any movement thereof), or Zavala's destroyers (and any movements thereof). Anything else was ignored as irrelevant since those destroyers never really did anything and abandoned ship immediately upon being warned and therefore had no information about whether a Hermes was near their position or not.

Still makes the Hermes a speedy little thing. Zavala had his Hermes in position within 86-90 minutes crossing ~540 light-seconds to be in zero-zero planetary orbit, while Terekhov's Hermes in Mobius took ~150 minutes(ish) to cross the ~732 light-seconds IF he deployed it within minutes of translating down.

That's approximately ~40% more distance to cover, and they surprisingly come pretty close for time. IF Terekhov launched within minutes of translation, assuming his Hermes travelled as the same speed as Zavala's, it would have taken ~104-105 minutes to be in zero-zero Mobius orbit, which is ~50 minutes short of the time he actually did open communications; which could imply that's either the actual max Hermes speed, or the Manticoran equivalent of "80% of max compensator" when applied to Hermes.


Anybody else remember Hermes usage where Manticorans weren't already in-system so we can see whether the distance & times keep matching up?
Top

Return to Honorverse