Distances in the Honorverse

penny wrote:It could also have to do with the cost as well as the complexity. After watching the movie Greyhound I looked up the cost of a radar system for warships. Mostly interested in our new destroyer. I am shocked at the cost:

The cost of a radar system on a warship can vary greatly, ranging from hundreds of thousands to hundreds of millions of dollars, depending on the type of radar, its capabilities, and the size and complexity of the vessel.
Here's a more detailed breakdown:

Simple Navigation Radars:
A basic navigation radar system like the Furuno 2120 might cost around $421,000, according to a Navy fact sheet.

Surveillance Radars:
New naval surveillance radar systems can average around $12.7 million, according to Armada International.

Advanced AESA Radars:
The AN/SPY-6, an advanced active electronically scanned array radar, can cost $300 million per unit in serial production, according to Wikipedia.

Radar for a Class of Ships:
The radar requirement for a class of ships like the FFG(X) frigates could be worth up to $25.5 million.

Radar Cost in Relation to Ship Cost:
While the radar itself is a significant cost, it's also a small fraction of the total cost of a warship. For example, the FFG(X) frigate class, estimated at $870 million per ship, is considered a relatively inexpensive surface combatant program.

It used to be, up until about WWII, that the size of a warship and its cost were very closely related. A ship 1/10th the size was roughly 1/10th the cost. And so if trying to save cost you'd go for a slightly smaller design.

And then radars, fire control computers, and other sensors started proliferating, and the main cost drivers of the ship were no longer its hull, armor, guns, and propulsion; but instead were its sensor suite and fire control.

So today while there are still fights over how big a new warship design should be they're largely arguing over the wrong things. Unless it's so big you need to build new drydocks to service the class the up-front costs are much more about what electronics you're sticking into it than how must steel is needed to build its hull. (And long term costs, at least in 1st world navies, are often about how large its crew is -- total lifetime crew costs add up fast). And in some cases building it bigger so you can use an existing off the shelf system, rather than having to design a custom scaled down version, will save money upfront and over the total lifetime. (Plus the extra size makes is more practical to install system upgrades over the fairly long life of current warships)

penny wrote:Interesting thread. I think it also has something to do with the minimum focal length of the Hubble telescope which is probably calibrated to infinity.

I think we can fix that in post

I think I first became somewhat aware of great distances when a teacher of mine challenged us to stand outside in the cold one morning before the sun arises to measure the time it takes to feel the sun’s warmth on your body when it rises. At 186,000 miles per second . That was an eye-opener for me.

Another good one to try is to give people a basketball and a tennis ball, say they're stand-ins for the Earth and the Moon (the relative sizes are roughly correct) and ask them to position the Moon to scale. Think about this yourself for a moment.

What did you come up with? Holding them with your arms in front of you? Holding them with your arms to your sides? Opposite sides of a basketball court?

The answer is "about 30 Earth radii," so about 24 feet or 7.3 m apart.

I think there's a Veritasium video on this.

The immensity of space is what makes me question the ability of GA sensors trying to make out totally stealthed infrastructure from the hyper limit. And GR drones whizzing by at breakneck speed with such a limited field of view is not going to detect an LD even if it flies 100 meters from it if it is looking in the opposite direction. The author explained that a missile’s field of view is akin to looking at the world thru the eye of a needle.

You know I disagree on the fact that the infrastructure could be stealthed in the first place. A new argument against them is that stealth technology is evolving, so it's unlikely the oldest infrastructure has the newest tech. The hodgepodge of different generations could lead to some being easier to detect.

Keeping everything up to date is an incredibly difficult and expensive task. Doing so without shutting down is nearly impossible - you'd probably need to do the updates all at the same time, because at least the chance of someone arriving at that exact time is smaller than if there's always something being down for maintenance.

It would be far easier to just have it in another system, one with a red dwarf or small orange dwarf for primary, with plenty of asteroids for mining. But no, we're told the shipyards are in the Darius system.

I recently watched a video (link below) about Aristarchus of Samos, who in the third century BC calculated the relative sizes and distances of the Earth, Sun and the moon using geometry. He then linked those numbers to the measured size of the Earth to get values that were within an order of magnitude of what we measure today. Really amazing.

Based on those numbers he decided that it was more reasonable that the Earth went around the sun in a year, than the sun going around the Earth in a day. Unfortunately there is an experimental problem with the stars that kept his work from being generally accepted.
The Ancient Mathematician Who Measured the Sun
The video runs just over 22 minutes.

Jonathan_S wrote:

Theemile wrote:Some other "Rough" distance analogies...
An SD’s wedge is roughly the size of the State of Connecticut.
A BC’s Length is a little less than the Width of NY’s Central Park (And ~2 blocks wide)
The Moon is in Laser and Graser range from Earth’s surface (Grasers have nearly 3x the range of the Earth to the Moon distance.)
A 3 drive MDM can hit Venus’ orbital path from Earth (in <9 minutes) with power to spare, and no coast stages.
Honor’s Demo attack on Tourville in AAC was the equivalent of firing missiles from Earth’s orbit, and hitting targets in Mars’s orbital path (OR targeting the Sun).

Actually an SD's wedge is quite a bit bigger than Connecticut.
From the infodump on wedge geometry (and some details dropped by, IIRC, Maxxq back in the day) an SD's wedge is roughly 300 km x 300 km [1]. While Connecticut is roughly 145 km wide and generally no more than about 90 km tall -- though it right near its western edge it finally angles down and picks up some extra height)

Also, for grasers, even against an unprotected target 3x the distance of the earth to the moon is rounding up pretty generously. As I recall, against a target unprotected by any sidewall, a graser has an effective range of about a million km, only 2.6x the ~384,000 km between Earth and moon. (And against a protected target cut that range basically in half)

Still, these quibbles aside, you're right that space is unimaginably vast and Honorverse ships or even stations are tiny small specks in comparison.

---
[1] Though a wedge is moderately inclined (15 degrees), and I don't know if that 300 km length is the length of the plane of the wedge, or how far it would appear if seen from directly above. So there's about a +/- 10 km possible variation in there.

<sigh> Yes, Connecticut is too small...

1st, sorry for the late response, I have been on a business trip, and was trying to get that post out before I left - I decided to add the other distance "errata" just before I sent the post, and absentmindedly looked up a list of state sizes, looking for a width of ~180 MILES. Of course, I didn't check the units, looked for 180, saw CT listed as 175, Thought it seemed too small, shrugged, and off I went.

And I should know better because:
1) Lesson #1 in college Engineering and Physics classes - "always check your units"
2) I lived in CT for a Year - it's not that big...
3) I was on the camera team for the Mars Observer probe, who got lost over a unit error on the thrust values of the engines. (It's a dirty little secret and been covered up, all because a programmer called the engine manufacturer to ask about thrust values, but failed to ask for the units...)

Orbital Speed and Altitude Relationship:

• Low Earth Orbit (LEO):

Objects in LEO, such as the International Space Station (ISS), orbit at relatively high speeds, around 7.8 km/s (17,500 mph), according to the Smithsonian Institution.

• Geostationary Orbit (GEO):

Objects in GEO, which is much higher, have orbital periods that match Earth's rotation (approximately 24 hours), so their orbital speeds are lower.

Were the space stations in the MBS in LEO or GEO? I always thought the HV’s space stations would be in GEO to match Earth’s rotation, so that the Palace, or Project Gram’s ground-side data backup, would always remain in the line of sight; and other reasons.

penny wrote:

[b]Orbital Speed and Altitude

Were the space stations in the MBS in LEO or GEO? I always thought the HV’s space stations would be in GEO to match Earth’s rotation, so that the Palace, or Project Gram’s ground-side data backup, would always remain in the line of sight; and other reasons.

I don't recall specifically, but I think given how little time there was between Oyster Bay and the impact on Yawata Crossing that HMSS Vulcan must have been in pretty low orbit. If it'd been orbiting 30,000ish km away there'd have been time for more than just the tug Quay to intercept some of the debris blown towards the planet. But they hit so soon there wasn't even time for the air limo carrying Allison and Raoul to land between when the emergency channels lit up with news of the attack and the impacts.

We know Quay was in the debris stream for 103 seconds, plus had a very small amount of time to react before entering it. But we're probably looking at under 5 minutes from the warheads going off until ground impact.

We're told those debris were traveling "at a paltry eight kilometers per second" -- that seems to put at least Vulcan's orbit no higher that 1,800 km. That's higher than a lot of current LEO missions but would still be lower than the 2,000 km that's generally taken as the upper limit of LEO.


I don't recall other references to the stations altitudes but there's benefits to being lower. It cuts down on the commute time between surface and station and puts it deeper in the defensive zone around the planet. And there doesn't seem to be a massive advantage to being geostationary. It's operating day isn't going to be dictated by the sun (and way out at geo its going to have much shorter nights than the point on the equator its 'hovering' over because of the way the earth's shadow works). It can operate on Landing time (or whatever) regardless of the height of its orbit.

A long line-of-sight transmission is likely less convenient (and might even be less secure) than a shorter one that often has to go through military relay satellites. (Plus Project Gram was mostly run out of HMSS Wayland -- over in Gryphon orbit, in Manticore-B. So it's not going to have many people groundside to be coordinating with since the Admiralty and Palace are orbiting an entire other star )

Also, given Honorverse tech, there is no reason to think that a station is in "Orbit". So it could have been stationary, or have a speed higher or lower than orbital - or some wacky trajectory placing it over specific planetary points at specific times of the day, at whatever height they want - because you can damn orbital mechanics when you are a repulsor lift society.

Theemile wrote:Also, given Honorverse tech, there is no reason to think that a station is in "Orbit". So it could have been stationary, or have a speed higher or lower than orbital - or some wacky trajectory placing it over specific planetary points at specific times of the day, at whatever height they want - because you can damn orbital mechanics when you are a repulsor lift society.

I thought about that as well. But that would be accepting a fuel penalty for not using the gravity that God gave us. Still doable but why would that be needed?
I also considered the orbital speed of the fleet, which I also thought would be in GEO so that it can readily communicate with the Admiralty or the Queen.

penny wrote:

[b]Orbital Speed and Altitude

Were the space stations in the MBS in LEO or GEO? I always thought the HV’s space stations would be in GEO to match Earth’s rotation, so that the Palace, or Project Gram’s ground-side data backup, would always remain in the line of sight; and other reasons.

Jonathan_S wrote:I don't recall specifically, but I think given how little time there was between Oyster Bay and the impact on Yawata Crossing that HMSS Vulcan must have been in pretty low orbit. If it'd been orbiting 30,000ish km away there'd have been time for more than just the tug Quay to intercept some of the debris blown towards the planet. But they hit so soon there wasn't even time for the air limo carrying Allison and Raoul to land between when the emergency channels lit up with news of the attack and the impacts.

We know Quay was in the debris stream for 103 seconds, plus had a very small amount of time to react before entering it. But we're probably looking at under 5 minutes from the warheads going off until ground impact.

We're told those debris were traveling "at a paltry eight kilometers per second" -- that seems to put at least Vulcan's orbit no higher that 1,800 km. That's higher than a lot of current LEO missions but would still be lower than the 2,000 km that's generally taken as the upper limit of LEO.


I don't recall other references to the stations altitudes but there's benefits to being lower. It cuts down on the commute time between surface and station and puts it deeper in the defensive zone around the planet. And there doesn't seem to be a massive advantage to being geostationary. It's operating day isn't going to be dictated by the sun (and way out at geo its going to have much shorter nights than the point on the equator its 'hovering' over because of the way the earth's shadow works). It can operate on Landing time (or whatever) regardless of the height of its orbit.

A long line-of-sight transmission is likely less convenient (and might even be less secure) than a shorter one that often has to go through military relay satellites. (Plus Project Gram was mostly run out of HMSS Wayland -- over in Gryphon orbit, in Manticore-B. So it's not going to have many people groundside to be coordinating with since the Admiralty and Palace are orbiting an entire other star )

Sorry about that. And thanks, I didn't get the memo. My fault, I'm always in bed with one or more of the characters.

Evenso, I would assume a space station would be in Geosynchronous orbit so that it can readily spurt backups to its ground-side station. So GEO orbit with a corresponding ground-side data reservoir.