Haven Victorious

tlb wrote:By base terminal velocity for the planet do you mean something like the orbital velocity?

The velocity achieved by the influence of gravity alone from a body at rest outside the atmosphere. A theoretical value which other variable will affect.

IOW, the minimum velocity without any braking effect or acceleration -- I'll let you math geeks figure out how that translates 650 Kg into "boom."

Weird Harold wrote:The velocity achieved by the influence of gravity alone from a body at rest outside the atmosphere. A theoretical value which other variable will affect.

IOW, the minimum velocity without any braking effect or acceleration -- I'll let you math geeks figure out how that translates 650 Kg into "boom."

Of course you are right; I apologize for misunderstanding you.

Weird Harold wrote:

tlb wrote:By base terminal velocity for the planet do you mean something like the orbital velocity?

The velocity achieved by the influence of gravity alone from a body at rest outside the atmosphere. A theoretical value which other variable will affect.

IOW, the minimum velocity without any braking effect or acceleration -- I'll let you math geeks figure out how that translates 650 Kg into "boom."

That's probably not terribly relevant, because an object dropped from a ship would HAVE to be accelerated in order to hit the planet. Otherwise it would just stay in orbit with the ship.

It takes something like 9 kps of delta v to get to geosynchronous orbit, but much of that is horizontal velocity instead of gravitational potential energy.

tlb wrote:By base terminal velocity for the planet do you mean something like the orbital velocity?

Weird Harold wrote:The velocity achieved by the influence of gravity alone from a body at rest outside the atmosphere. A theoretical value which other variable will affect.

IOW, the minimum velocity without any braking effect or acceleration -- I'll let you math geeks figure out how that translates 650 Kg into "boom."

Galactic Sapper wrote:That's probably not terribly relevant, because an object dropped from a ship would HAVE to be accelerated in order to hit the planet. Otherwise it would just stay in orbit with the ship.

It takes something like 9 kps of delta v to get to geosynchronous orbit, but much of that is horizontal velocity instead of gravitational potential energy.

In fairness to his point, the ship does not have to be in unpowered orbit - your hypothesis. It could be using power to maintain position over the target.

Galactic Sapper wrote:

Weird Harold wrote:A theoretical value which other variable will affect.

That's probably not terribly relevant, ...

You apparently missed the words "theoretical value" -- the theoretical minimum velocity of a dropped object through Standard Temperature and pressure of a planetary atmosphere.

That is the determinator for the theoretical minimum yield for a 650Kg RMN KEW.

ETA: Of course since there is a minimal drive and guidance package, the drive could be used to decelerate the KEW to very near the target and simply drop a 650Kg weight on an individual standing in the open so they target only suffers damage equivalent to a piano pushed off a four or five story building -- no "Boom," just "Splat!"

Weird Harold wrote:You apparently missed the words "theoretical value" -- the theoretical minimum velocity of a dropped object through Standard Temperature and pressure of a planetary atmosphere.

That is the determinator for the theoretical minimum yield for a 650Kg RMN KEW.

ETA: Of course since there is a minimal drive and guidance package, the drive could be used to decelerate the KEW to very near the target and simply drop a 650Kg weight on an individual standing in the open so they target only suffers damage equivalent to a piano pushed off a four or five story building -- no "Boom," just "Splat!"

If we must...

Ideally, gravitational potential energy is simply mass times gravity times height. This ignores the change in local gravity over orbital height distances, uses Earth gravity which may differ greatly from local gravity, and ignores air resistance entirely (technically, air resistance doesn't affect GPE, but it would affect how much of that energy bleeds off on the way to the ground).

Assuming a convenient 2000 km (low earth orbit) stationary drop, 650 kg would give you 0.00304 kt upon impact on the ground - remarkably similar to the low yield SLN strike at the beginning of SoF. Air resistance would reduce that a bit, but probably only a couple percent if the dart is nicely aerodynamic.

The much bigger issue is that gravity reduces with distance squared. In an Earth-standard gravitational field, a KEW at 2000 km is going to start falling at 7.46 m/s^2, not 9.8 m/s^2. This changes continuously during the fall and only reaches 9.8 m/s^2 at ground level. That is going to significantly reduce the energy, but my calculus is way too rusty to even attempt that calculation (and I couldn't find one online).

Obviously higher drop points and larger masses give bigger booms.

tlb wrote:By base terminal velocity for the planet do you mean something like the orbital velocity? The energy is still proportional to the square of the impact velocity, no matter what other factors you wish to bring in (as long as we do not get relativistic). But picking a specific impact velocity may involve your additional factors, however the only velocity that needs to be considered is the motion of the target compared to the ship based on planet rotation and ship orbital speeds.

You could have less velocity than the orbital velocity if the KEW launcher and/or it's drive canceled out some (or all) of the original orbital velocity of the launching ship (or if the ship used it's drive to cancel out its orbital velocity before launching the KEW).

The THOR kinetic bombardment system the US toyed with couldn't reduce it's velocity like that because the tungsten rods didn't have drives capable of completely counteracting their orbital velocity - but Honorverse KEWs do. (Though I suspect you can't use them once in the atmosphere to cancel some of your velocity; they're probably designed to only accelerate 'forward' and the KEW probably isn't aerodynamically stable if it tried to come down backwards. So I suspect the minimum achievable impact speed would be simply from canceling all orbital speed and letting gravity pull the KEW straight down from just outside the atmosphere - though it's possible sufficiently large control surfaces could let you pull off some velocity bleeding turns on the way down)

Jonathan_S wrote:You could have less velocity than the orbital velocity if the KEW launcher and/or it's drive canceled out some (or all) of the original orbital velocity of the launching ship (or if the ship used it's drive to cancel out its orbital velocity before launching the KEW).

The THOR kinetic bombardment system the US toyed with couldn't reduce it's velocity like that because the tungsten rods didn't have drives capable of completely counteracting their orbital velocity - but Honorverse KEWs do. (Though I suspect you can't use them once in the atmosphere to cancel some of your velocity; they're probably designed to only accelerate 'forward' and the KEW probably isn't aerodynamically stable if it tried to come down backwards. So I suspect the minimum achievable impact speed would be simply from canceling all orbital speed and letting gravity pull the KEW straight down from just outside the atmosphere - though it's possible sufficiently large control surfaces could let you pull off some velocity bleeding turns on the way down)

I was completely off base earlier, because I had misunderstood what Weird Harold was stating. But since then I pointed out that the ship does not have to be in an unpowered orbit, but could simply be holding station directly over the target. That may be a more likely scenario and makes the targeting much simpler.

runsforcelery wrote:Would a treaty negotiated by an Alexander government have been as beneficial for both sides, even with treecat intervention, as what finally emerged as the Grand Alliance? Almost certainly not. But the delay in negotiations had nothing at all to do with Elizabeth. It was solely the fault of High Ridge and his allies, and she would cheerfully have shot the lot of them herself if she could have gotten away with it!

I've always found that hard to believe.

Elizabeth could have colluded with Benjamin, and HE could have sent "Steadholder Harrington" off to negotiate a peace treaty with Haven at any time.

And if Harrington had come back with an acceptable treaty, endorsed by Grayson, and presented it to the House of Lords with Elizabeth's backing, the war would have ended, High Ridge would have lost his war taxes, and they'ed have been forced to hold an election (which would have let in a bunch of new members of the House of Lords, none of whom had anything positive to say about High Ridge).

Crown Loyalists plus Centrists plus Liberals would have been enough to accept a worthwhile Peace Treaty, and there's no way the Liberals could have held on to their self regard while rejecting a valid PT.

runsforcelery wrote:Would a treaty negotiated by an Alexander government have been as beneficial for both sides, even with treecat intervention, as what finally emerged as the Grand Alliance? Almost certainly not. But the delay in negotiations had nothing at all to do with Elizabeth. It was solely the fault of High Ridge and his allies, and she would cheerfully have shot the lot of them herself if she could have gotten away with it!

GregD wrote:I've always found that hard to believe.

Elizabeth could have colluded with Benjamin, and HE could have sent "Steadholder Harrington" off to negotiate a peace treaty with Haven at any time.

And if Harrington had come back with an acceptable treaty, endorsed by Grayson, and presented it to the House of Lords with Elizabeth's backing, the war would have ended, High Ridge would have lost his war taxes, and they'ed have been forced to hold an election (which would have let in a bunch of new members of the House of Lords, none of whom had anything positive to say about High Ridge).

Crown Loyalists plus Centrists plus Liberals would have been enough to accept a worthwhile Peace Treaty, and there's no way the Liberals could have held on to their self regard while rejecting a valid PT.

I am not sure that is correct: to begin with the sticking points were between Haven and Manticore, so it is hard to see that they could first be negotiated between Grayson and Haven, and second that the ruling coalition would have accepted anything binding Manticore from a negotiation between Grayson and Haven.
Basically the ruling coalition, including the Liberals, would claim that this was not a valid Peace Treaty as far as Manticore was concerned. They have too much invested in the current stalemate to allow themselves to be flanked in the way you suggest..