Enter the Fray

[monbvol]

I did not entirely realize I was looking at the 'upgraded' version of TRO 3057 Revised for the Excalibur and how much that cuts back the Heavy Vehicle and Infantry Bays.

That is an interesting consideration.

The upgraded version has enough for a Regiment with a command company.  The obsolete version handles 12.5 companies, which is a rather reinforced Regiment.

Hmmm those extra bays would be a nice way to transport dependents without having to do a bunch of extra customization work on the Mammoths and not use up a lot of extra supplies.

[Dave Talley]

also bays could be subdivided by using pods which are later removed from the ship and set up as housing

ie like modern usage of cargo containers, can be used for damned near anything

[Daryk]

You need 32 for a 'mech lance (4 MechWarriors, 4 Techs, 24 AsTechs).

As for the orbital asset, you could rotate crew... and you'd be even more motivated to if it didn't have a grav deck.  Small craft or ASF carrying cargo would work for shuttling people up and down, without requiring a DropShip to work.

[monbvol]

30 is still plenty fine to absorb the support elements that are not in the direct combat TO&E overall.  Especially if a unit makes members pull double duty.  Which given the limitations presented in the setting is a doctrine utilized by just about everyone but the Clans to some extent.

Still not inclined to leave even a stripped down Jumpship in orbit as that'd just stretch things further having to support small craft and an orbital station on top of everything else.

[Daryk]

Rog... then it should be mothballed in a stable orbit somewhere in the system.

Double duty will get you there with just 30, though it's suboptimal.

[Dave Talley]

with a little planning it could be placed in a synchronous orbit where its sensors can still be used via radio from the dropships, at least enough to warn of a warp signature

[monbvol]

I do call out in the story that they are able to detect emergence waves.  The grounded Dropships should actually be plenty for that really though without needing a relay with how far out such things can be detected from.

Though I may have to check when I had some fights happen after someone jumped into the planet/moon lagrange/pirate point because I think I may have had some happen at dusk when it should have been dawn.  Darned orbital mechanics.

[idea weenie]

I do call out in the story that they are able to detect emergence waves.  The grounded Dropships should actually be plenty for that really though without needing a relay with how far out such things can be detected from.

Though I may have to check when I had some fights happen after someone jumped into the planet/moon lagrange/pirate point because I think I may have had some happen at dusk when it should have been dawn.  Darned orbital mechanics.

Have them jump to the planet-star LaGrange point instead.
Using Earth as an example
Earth-Sun LaGrange - ~1.5 million km
Earth-Moon LaGrange - ~325,000 km

Ratio: 4.6
Since travel time comparison for constant thrust is based on the square root of the distance (i.e. a distance 4* as far will take twice as long), this distance will take the raiders about 2.15 times as long.


But shooting for the planet-Sun LaGrange is likely easier than aiming for the planet-moon LaGrange.  It does give the locals more time to get ready, but it is a much bigger target.

That could have been a good indication that the Clans were different, as they would pop to the planet-moon LaGrange thanks to better systems and navigators.

[monbvol]

Yeah detecting traditional zenith/nadir jump emergence signatures isn't too problematic.

I just figure pirates would use the planet moon point expressly because it does give the defenders less time and it isn't that much of a risk to the pirates.

Which the Falcons used too because they got the coordinates from the pirates and yeah they'd be crazy enough to use them.

The only real issue is if I don't have an orbital relay for the colony the planet gets in the way unless it is night time and transit time would put the invaders down in the morning in such a scenario.

Wolves used the standard zenith point.

Which makes me realize there is another factor working against the colony having an orbital relay.  They would not be able to effectively defend it and that'd be the first thing I'd go after as a pirate.

[Daryk]

I'm not convinced the planet-moon L1 point works... the star's gravitational field enters into the calculations.  Three body problems suck.

[monbvol]

Non-standard points have been used in other fiction before and there is a reason the common term for them is 'pirate point'.

It is a more difficult calculation more reliant on having more detailed charts of the system in question but certainly not impossible.

The biggest issue would actually be the Jumpship would have trouble staying inside the point as it would be stationary relative to the point while the point would move with the orbital mechanics but even this isn't impossible to overcome maxing the station keeping drives.

[Daryk]

I guess what I'm saying is that the gravitational field of the star throws the calculations off enough to no longer make it meaningfully close to the planet-moon L1 point.

[monbvol]

It'd still be a much shorter transit than from zenith/nadir and pirates like shorter transit times.

Planet moon points are actually incredibly stable/predictable and despite being called points can actually fit a rather large fleet without issue.

Now yeah do not attempt unless you have a good navigator and the jump computer is working in top form.

[Daryk]

Your game... I'll withhold judgment until I see/do the math...

[monbvol]

StratOps page 88 gives such a point a +4 modifier to the control roll and the standard nadir/zenith point would be 8.53 days versus a few hours for planet moon for the star type I chose.

[wanderer25]

Rog... then it should be mothballed in a stable orbit somewhere in the system.

Double duty will get you there with just 30, though it's suboptimal.

Or maybe the JS crew decided to become free traders with the colony as their homeport. It would provide the colony with an influx
of tech/goods.  Also means they are not always around.

[idea weenie]

I'm not convinced the planet-moon L1 point works... the star's gravitational field enters into the calculations.  Three body problems suck.

It doesn't.  But it is close enough to an actual near zero-G point that a Jumpship can pop in, and after arriving the Jumpship thrusts to orbit the actual planet-moon L1.  (This may need some fan rules, where a small enough moon means that ships over a total mass of Y tons cannot arrive there due to the near-zero region being too small for them)

I use planet-Moon L1 to refer to the approximate location of the pirate point so people can have an idea of where it is located, not where it is actually located.  It can tell the person that it is between the planet and moon, and much closer to the moon than the planet.

The sun will adjust the actual near Zero-G location closer towards itself of course, but being so close to the planet and Moon means their gravity plays the primary part in determining the location.  Similarly, the planet-star pirate point is affected by the plant's moon, but the planet and star are the primary determinants of the pirate point location.

Technically, I should be referring to it as the planet-moon Pirate Point.  People would see what two bodies it is located mostly between, and would understand that the location is much closer to the smaller than the larger one.    :-[

[Daryk]

If it works at all, it would only be when all three bodies are aligned.  If the planet-moon line is perpendicular to the planet-sun line, there's no cancellation of the stars gravitational field between the planet and moon.

[monbvol]

If it works at all, it would only be when all three bodies are aligned.  If the planet-moon line is perpendicular to the planet-sun line, there's no cancellation of the stars gravitational field between the planet and moon.

Planet moon points are always there and are incredibly stable no matter the orbital positions.  Sure they shift and possibly change size but both of those factors are so predictable/trivial to deal with that it is mostly to establish certain setting elements that they are not used as standard points.

It doesn't.  But it is close enough to an actual near zero-G point that a Jumpship can pop in, and after arriving the Jumpship thrusts to orbit the actual planet-moon L1.  (This may need some fan rules, where a small enough moon means that ships over a total mass of Y tons cannot arrive there due to the near-zero region being too small for them)

I use planet-Moon L1 to refer to the approximate location of the pirate point so people can have an idea of where it is located, not where it is actually located.  It can tell the person that it is between the planet and moon, and much closer to the moon than the planet.

The sun will adjust the actual near Zero-G location closer towards itself of course, but being so close to the planet and Moon means their gravity plays the primary part in determining the location.  Similarly, the planet-star pirate point is affected by the plant's moon, but the planet and star are the primary determinants of the pirate point location.

Technically, I should be referring to it as the planet-moon Pirate Point.  People would see what two bodies it is located mostly between, and would understand that the location is much closer to the smaller than the larger one.    :-[

I seem to recall a discussion where someone with more authority on the matter did confirm the Earth Luna pirate point would have been more than big enough for Kerensky to jump his fleet into without any worry of collisions or emergence fields screwing up allied vessels.  I want to say it was cray himself but with how much my memory fails me anymore that is probably wrong and it would not surprise me if it were a prior incarnation of the boards on top of that.

[Daryk]

Yes, the gravity of the planet and moon always cancel between them, but the gravitational field of the star dominates.  That's why the standard jump points are so far away.  If the moon and planet aren't working together to cancel the star, no jump point.

[monbvol]

I was correcting that it does not take the bodies to be in alignment for a planet moon point nor does it go away if the bodies become perpendicular.

[Daryk]

 ???

[monbvol]

If it works at all, it would only be when all three bodies are aligned.  If the planet-moon line is perpendicular to the planet-sun line, there's no cancellation of the stars gravitational field between the planet and moon.

This statement.  Where you say the bodies have to be aligned or the point goes away if they become perpendicular is incorrect.  Planet moon never goes away.

[Daryk]

Just because the planet and moon gravitational fields cancel one another doesn't cancel the star's field.  That's what I'm saying.

[monbvol]

Which is not correct for a planet moon L1 point.  I feel I need to recommend reading up Strat Ops 86-88 and 134-135.

[Dave Talley]

this is why stations are commonly built in stable L1 L2 etc points

a ship could jump in, and in theory if it matched velocity to stay in that spot it would simply orbit
without a problem, and honestly any inhabited system will have astrogational charts good enough
to jump into with virtually no issue, its not like moons deviate in course or anything

[Daryk]

Page 86 has this:

Because of the very nature of transient points, they are not covered by the following rules.

Pages 134-135 are in agreement with my well over 20 year old Physics degree (and Astronomy minor).  As I said earlier: three body problems are HARD.  You will not find a region of sufficiently low gravitational force between a planet and moon when they form an isosceles triangle with the star.  That jump point will be closer (on an astronomical scale) to the planet-star L1 point.  Star mass exceeds planet (and moon) mass by MANY orders of magnitude.

[monbvol]

Lagrange points are not all transient points though, it even goes into it:

Transient points can be anywhere in a system and can come
and go in seconds, though they are generally a sub-class of Lagrange points.

[quote authore=Strategic Operations page 134]The two types of pirate points are transient points and LaGrange points, and they occur inside the proximity limit of systems. LaGrange points—not LaGrange jump points—are regions of space where the gravity of two bodies and centripetal force end up canceling.

You can look up LaGrange points on your own; this isn’t an orbital mechanics class.

One of those LaGrange points, the so-called “L1 point,” is a place formed by the effective cancellation of gravity between the two bodies.
Relatively near that place is often an area where gravity for most influential bodies is cancelled to a level safe enough to use a K-F drive. When you subtract the influence of centripetal force, you find the point of stability is closer to the larger of the two bodies by a distance that depends on…well, the relative size of the two bodies and influence of any other substantial bodies in the system.

A planet-moon L1 point often wiggles around a lot based on the input of the local star. However, if you can imagine
how a planet and moon forming an L1 point are whirling around a star together, and you imagine how small a valid jump area is formed in this fashion, you can imagine how much more complicated it is to arrive at such a LaGrange point than at a standard jump point
[/quote]

In other words it is stable and doesn't go anywhere like a transitory jump point.

[Daryk]

Page 135 goes on to say:

The actual jump point will wiggle around the real L1 point due to the influence of the local star and planets.

The star enters into the calculation, and the L1 point discussed here is between the two largest masses (the star and planet).

[monbvol]

Wiggle, not disappear.  Which I've said many times now.

If it were transitory at all there would be no need to split the terms like they did.