OOPS

tlb wrote:

cthia wrote:You misunderstood me. Moderator rods are NOT "formally" referred to as fuel rods. Or vice versa. How can they be? They are two different things. I simply accepted what another poster wrote because I have seen the term used interchangeably in graphite moderated reactors. But again, I could have been wrong.

The terms were sometimes used interchangeably because of the design. AS I UNDERSTOOD. And yes, the graphite assemblies are huge. The rods sometimes numbered in the several thousand.

I looked back and it appears you were the first to say fuel reds were moderator rods here:

cthia wrote:The control rods are NOT the moderator rods. The fuel rods are both the coolant and moderator rods.

Control rods reduce the reaction rate. Reactors are sometimes shut down to replace spent or depleted fuel rods, but other reactors remain running to supply the necessary power to support the fail-safe systems.

The only earlier mention wrote the control rods were "moderator rods" and this was your response.

Yes, I said that. And I was wrong.

It feels strange to be wrong. It feels good to admit it.

cthia wrote:Not necessarily. The current yield of our present nuclear bombs is limited only by our inability to solve the problems that have been solved in the Honorverse. I would imagine there are insane yields of nuclear devices in the Honorverse. After all, nuclear energy is nothing if not efficient.

There's no point to bigger bombs--once you get past 20 megatons the bomb's destruction doesn't go up much as you increase the yield.

There is one mission for bigger bombs--orbital bombs, either for EMP or thermal pulse. (A big enough bomb can light fires out to the horizon--and from very low orbit the horizon is very far away.)

We also know how to build bigger bombs. A normal hydrogen bomb uses the energy of an atomic bomb to compress the lithium deutride. The size of the bomb is limited by how much energy you have to compress it. (Which is not the full energy as you can only catch what's heading in the right direction.) There are two things you can do to increase the energy, though:

1) Most of the energy of the fission bomb just heads off in a direction without a second stage. You can place several second stages around the fission trigger (although using more than two second stages ends up with a bomb like a caltrop or jack, a pain to handle!) Each stage must be alike so they go off at exactly the same time. (You don't need nanosecond level timing, though--the fusion stage's timing is based on the materials used, no clock is involved.)

2) Fusion bombs are normally triggered by fission bombs but anything energetic enough will do the job. You can detonate a fusion bomb with another fusion bomb--stacking a second fusion stage in line with the first (it must be shielded from the fission stage by the first fusion stage or it will be destroyed before it detonates.) You now have megatons of energy to play with rather than just kilotons, the third stage can be considerably bigger than the second. You can even have a line of a fission bomb bracketed by two second stages which are bracketed by two third stages. If that's not enough you can extend the line with ever-bigger stages. There's no upper limit.

Loren Pechtel wrote:There is one mission for bigger bombs--orbital bombs, either for EMP or thermal pulse. (A big enough bomb can light fires out to the horizon--and from very low orbit the horizon is very far away.)

A 100 megaton bomb at a few hundred KM in a clear October day over say Scranton PA would set the United States on fire from say Bangor to Raleigh to Cincinnati as all the dry leaves ignited. It wouldn't would out well for Ontario either, but they wouldn't be the target.

Galactic Sapper wrote:There's actually a decent argument for low orbit: the transit time of the debris entering the atmosphere. If they'd been in lagrange orbits the debris would have taken hours to hit the planet, or more likely would have simply fell into a much closer eccentric orbit. Even a 25000-ish km synchonous orbit would have allowed for reaction and mitigation time.

Transit time can't be it.

A pinnace or shuttle accelerating at 20 gravities can cover 600 km (from 0 speed to 0 speed) in 110 seconds. 6000 km would less than 6 minutes. Geostationary (36000 km) increases that only to 15 minutes. The biggest delay is going to be Air/Orbital Traffic Control, boarding, etc.

Besides, a 100 km x 40 km wide station 600 km up is about 10° by 4°. That's 20 by 8 moon diameters (160 times the apparent size) and would cast big shadows on the planet and would shine very brightly at night, as it's much closer, much bigger and is made of metal, not regolith. Another way to think about it is that your fist at the end of your extended arm is about 10°.

You do have a point on debris striking the planet, though. Because we know they did in Gryphon, HMSS Vulcan can't have been too high. The chunk of the station wasn't accelerating, so if it struck in less than 5 minutes, it had a radial velocity of 2000 m/s (7200 km/h, 4473 mph) if it was at 600 km altitude. For it to have been at 9000 km altitude, it would need 30 km/s.

There is one more possibility I don't think has been considered. It still falls into one of the groups Theemile pointed out. Shannon could have somehow caused a huge power surge that blew back into the reactor. IINM, power surges caused a couple of reactor failures in storyline. It would have had to be a huuuge surge.

ThinksMarkedly wrote:Transit time can't be it.

A pinnace or shuttle accelerating at 20 gravities can cover 600 km (from 0 speed to 0 speed) in 110 seconds. 6000 km would less than 6 minutes. Geostationary (36000 km) increases that only to 15 minutes. The biggest delay is going to be Air/Orbital Traffic Control, boarding, etc.

Yeah, their acceleration make the orbital distance from the planet a fairly trivial part of the commute time.

This may fall under your "be Air/Orbital Traffic Control" but I'd elaborate a little and point out that:

A) Post OB Beowulf (and presumably everybody else in the GA) increase the size of the low velocity, no active wedge, zone around their orbitals. So that departure or approach using relatively minimum thruster power it going to take quite a while to cross that zone (and even before OB there was a reasonably large safety buffer to minimize the risk of accidental wedge to station contact).

B) As is passing through the atmosphere. Even pinnaces and shuttles don't seem to use their wedge in any serious atmosphere. They use counter-grav and a combo of air-breathing and rocket engines to climb out to an altitude where wedge use is allowed, or those engines plus drag from reentry to drop down through the atmosphere. So again that's going to be much lower acceleration than even the low 20g you used for while under wedge.


So atmospheric maneuvering and no-wedge approach/departure zones eat up the bulk of your planet to station commute time. The high acceleration bits in the middle are comparatively quick.

Jonathan_S wrote:So atmospheric maneuvering and no-wedge approach/departure zones eat up the bulk of your planet to station commute time. The high acceleration bits in the middle are comparatively quick.

True too. If you accelerated at a measly 2 gravities, you'd be supersonic in 34 seconds. It's very likely that shuttles and pinnaces aren't allowed to go hypersonic close to population centres, so they have to climb at moderate speeds before engaging the main engine (whatever that is, if it isn't a wedge) to reach orbital velocity.

That's even if they have something that negates the effects of the sonic boom. There has to be a slow departure and approach speed for safety reasons.

Another thought: Lets look at a lower level.

We know how bad their software security is, lets exploit that. Send some configuration updates for the reactor control software. Nothing major, just add a few meters to the size of the reaction chamber.

The plasma eats the reactor chamber walls and eats through the systems holding it in place.

Jonathan_S wrote:
A) Post OB Beowulf (and presumably everybody else in the GA) increase the size of the low velocity, no active wedge, zone around their orbitals. So that departure or approach using relatively minimum thruster power it going to take quite a while to cross that zone (and even before OB there was a reasonably large safety buffer to minimize the risk of accidental wedge to station contact).

I'm guessing that you could actually do a lot of this with a tractor on the station. Given that they can move things outside a 300 km wide wedge the have a decent range. So you could accelerate up to the grav plate limit, which will get you going 10 km/sec at 30G and a 200km tractor range. (I can't remember the actual limit. Returning they would have a trajectory that won't actually intersect the station without the tractor.

kzt wrote:

Jonathan_S wrote:
A) Post OB Beowulf (and presumably everybody else in the GA) increase the size of the low velocity, no active wedge, zone around their orbitals. So that departure or approach using relatively minimum thruster power it going to take quite a while to cross that zone (and even before OB there was a reasonably large safety buffer to minimize the risk of accidental wedge to station contact).

I'm guessing that you could actually do a lot of this with a tractor on the station. Given that they can move things outside a 300 km wide wedge the have a decent range. So you could accelerate up to the grav plate limit, which will get you going 10 km/sec at 30G and a 200km tractor range. (I can't remember the actual limit. Returning they would have a trajectory that won't actually intersect the station without the tractor.

You might be able to on a technical level, but we know historically that Beowulf wasn't using such an method because there's a scene in UH where White Haven is contemplating the extra delay as his shuttle creeps towards the Beowulfan orbital across this expanded low speed, no-wedge, zone imposed after OB.


Also I'd think that they'd be worried about letting vehicles flying even somewhat near the station at high velocity, even on non-intersecting courses. That doesn't give much time to react if the course changes enough to intersect the station, or simply if the vehicle explodes itself and the high base velocity makes the expanding cloud of debris more deadly. (And of course, even ignoring hostile action, high base velocities reduces the time and ability to react if a screw-up had another vehicle or EVA suit accidentally cross the path of the high speed inbound shuttle.