Quotes reordered to avoid silly embedding limit.
BobfromSydney wrote:I think the point about the missiles being spread out across multiple light seconds during their flight makes sense.
However I was not suggesting using the Planet/Moon Lagrange points, I was suggesting using the Star/Planet Lagrange points. Planet/Moon are obviously inadequate in terms of creating a 'safe' separation.
Now even using the conservative value of 2 light seconds (600,000km), a 10,000 diameter planet would represent less than 1 degree of arc from the 600,000km point. So once you discount the missiles that are destroyed, disabled or decoyed before reaching target, those that actually are on target, those whose on-board 'safeties' function correctly and those that are not on a straight-line kinetic collision course with the planet, you will be left with very few missiles indeed. Perhaps only a handful, certain no more than a few dozen. Those would be fairly simple to take out with CMs/PD or wedge-block using block ships (including LACs, Destroyers or even freighters.
As to a fleet being spread out across a space a couple of light seconds across, okay, that's possible, although I imagine the 'wall of battle' component (which launches the MDMs) would be more concentrated than that.
But even a 2 light-second separation at a 2 light-minute distance is less than one degree of arc. At 1 light-minute (18 million km) it is still less than 2 degrees of arc.
My point is that the enemy fleet would practically have to deliberately target the planet in order to have a meaningful number of missiles 'collateral' the planet upon missing. Although the word would probably be COLINEAR, rather than COLATERAL if you take my meaning.
Vince wrote:Using the Sun Earth Lagrange points as an example.
Reference
Lagrangian point from Wikipedia.
Consider the layout of the Lagrange points as shown in this diagram:
The least time course that an attacker can be expected to take (with no resonance zones involved) from the hyper limit is the dotted line drawn from the Sun through Earth and the L1 & L2 points and extending further to the right to the hyper limit.
We can immediately rule out L3 for defense of the planet, as it lies on the opposite side of the sun from the planet.
L1 might be useful if you want to hide missile pods from an attacking fleet. (Is this where the RMN hid the pods in the shadow of the planet Spindle from the point of view of Crandal's fleet in Storm From the Shadows?) But if you want to avoid the possibility of having an attacking fleet accidentally hitting the planet when it fires on your pods, it has the same problem that L2 below has.
L2 could be used, but if the point is to have the attacking fleet fire on them and avoid accidentally hitting the planet, the planet is directly behind it from the attackers point of view. (If they are coming in on a least time course from the hyper limit.)
For both
L4 and L5, the Sun, Earth and the Lagrange point, form an equilateral triangle with the length of the sides being the same as the radius of the Earth's orbit around the Sun (1 AU, 149,597,870,700 meters, or 499.004784 light seconds ~= 8.3167 light minutes).
So the questions for the defender (with Apollo system defense missiles) are:
1) Do the Apollo system defense missiles have the reach (active fire control) to reach out much more than 8.3167 light minutes? (You want to intercept the attackers with your missiles before they reach a position where they can fire on Earth, which will increase the range the missiles have to travel.) Keep in mind that in At All Costs, Honor's demonstration attack against 2nd Fleet was a bluff - she couldn't control more than a handful of missiles at a range of 150,000,000 kilometers. (Which may not be an issue if a system is designed to control many more missiles - Mycroft?)
2) Can the missiles make it to the attacking fleet before the attacker gets into their missile attack range of Earth?
3) Does the attacker have SDM's or MDM's? If they have MDM's, #2 above becomes much more difficult to answer yes.
4) For a different star system than Sol, how far is the planet from the hyper limit? Which impacts also #2 above. For example, this will not work against a fleet attacking Sphinx if it isn't in the resonance zone if the attacker has MDMs.
BobfromSydney wrote:
I am advocating using the star/planet L2 as the deployment point for a large concentration of 'planetary' pods (if maintenance and FC issues for pods are not a big problem they should not even be near the planets of course).
Although I agree that stray missiles going toward the planet are a threat if they impact I do not think it is a serious threat.
If the L2 point is 2 light seconds away and the planet has a diameter of 10,000km, drawing a cone from the L2 point to the planet the disc of the planet is only 0.95 degrees in diameter. This can be approximated by attempting to hit a snooker (pool) ball from 3.166 meters (roughly 11 feet) away by flicking a laser pointer on-and-off. Considering the difficulty of long-range astrogation I doubt that an arriving fleet would be able to arrive precisely aligned with planet & star within a sub 1 degree cone after a journey of many light years. Any 'leakers' can be taken out with CMs and PD with some block ships thrown in to close down angles against vital points (cities, large space stations etc.)
One interesting discovery I made was that in order to cover a disc of about 14,000km in diameter with block ships completely you would need over 1750 ships with 300km square wedges (i.e. 90,000km^2).
Addressing your numbered points
1. Using such distant Lagrange points seem to be non starters to me (unless small reserves are placed to defend 'nearby' asteroid facilities etc.)
2. See reply to 1
3. As above
4. From what I've read in this thread, Manticore and Sphinx actually have longer distances from Manticore A than Earth does from Sol, likely the L2 points for Manticore and Sphinx would be further as well. This means that the pool ball might be further away (5 or even 10 meters away) meaning it is far less likely for leakers to be on an intercept with the planet.
I would also point out that rather than trying to hit the planets, attacking fleets would generally try to MISS the planet with overshoots. Since missiles can spread out during the mid-flight etc. it would be fairly trivial to order the flight paths so that overshoots do not intersect the planet.
On the other hand if an opponent really wants to commit an Eridani violation with MDMs then I don't think it is even possible to stop them from landing at least one missile.
There is a third case where the opponents would like an 'excuse' to commit Eridani violations but won't do so 'unprovoked'. But wouldn't a stockpile of ready pods in 'orbit' around a planet (or anywhere in the vicinity) give such an excuse anyway to such an opponent?
Regarding 4: Data from House of Steel: The Honorverse Companion
The Manticore-A diagram lists Manticore as 11.5 light minutes from the star. For Sphinx, it is 21.2 light minutes. The hyper limit is given as 22 light minutes.
The Manticore-B diagram lists Gryphon as 11.4 light minutes from the star. The hyper limit is given as 21.1 light minutes.
As for the basic idea of keeping missile pods at L2:
The problem for any attacker who wishes to avoid an Eridani violation is that they must control the orbitals of the planet and then issue a surrender demand to the government. That means defeating any defenses (forts, etc.) in planetary orbit after dealing with any mobile units in the system.
Regardless of the direction the attacker chooses to approach the planet, if they are using missiles to attack the orbital defenses, there will be at least some defenses in planetary orbit on a direct line between the planet and the attacking fleet, which the attacker will have to wait until the defenses travel in their orbit to a point where they are no longer on that direct line.
As for keeping shoals of pods at L2 for defense of the planet (especially without any defenses in orbit to back them up), there are a few ways to defeat, or at the very least complicate things for the defender using this tactic.
One is to approach from the opposite direction of a least time course (similar to what Thunder of God tried to do in The Honor of the Queen in the Yeltsin system against Grayson, but fighting through any mobile units deploy against the attacker). The defender now has the problem that the planet is between the missile pods and the attacker.
Another is to execute a polar approach (what Admiral Khumalo sp? did at Monica at Eroica Station) against the L2 point, then without crossing the hyper limit fire MDMs (or even SDMs) at the L2 point, with old-fashioned nukes (sent in ballistic) to take out the pods with proximity soft kills (like the planet, pods can't dodge), then hyper out. Reload in hyper-space (the way Tourville did when he attacked Zanzibar), then come back for the planet before the defender can replace the pods. (Or just stop relative to the L2 point at a distance where you can send missiles in ballistic and the defender can only fire ballistic missiles in reply. This is the weakness of fixed minefields and missile launchers without mobile units or fortresses to back them up, discussed about the Hades defenses in Echoes of Honor.)
You could also combine the two ways. First send your first force to attack coming from opposite a least time course to draw out any mobile units, then send your second force to first take the pods out at L2 using missiles sent in ballistic, reload in hyper and then move to secure the planet's orbitals before the defenders mobile units can get back in position and reload their magazines, at which point you issue your surrender demand. If the planet doesn't surrender, you are within your rights to begin targeted KEW strikes against the planet.
