Attacking Darius:

tlb wrote:There is a problem (I do not know the severity) when two stealth spider-drive ships get back to back, since they are both trying to radiate heat out of the back; you would seem to have created an example of a black-body heat source - now sideways out of the gap between them.

That's what I thought too. If it were possible to block the radiating with something that easily, it would have been done. Consequently, the fact that it wasn't means it can't be done (or no one has come up with a way to do so).

The other danger is that if each ship is radiating in the direction of the other, they're effectively bathing each other in warmth, which means those ships will be warmer than the interplanetary medium.

ThinksMarkedly wrote:
That's what I thought too. If it were possible to block the radiating with something that easily, it would have been done. Consequently, the fact that it wasn't means it can't be done (or no one has come up with a way to do so).

The other danger is that if each ship is radiating in the direction of the other, they're effectively bathing each other in warmth, which means those ships will be warmer than the interplanetary medium.

There is a whole lot of issues with the laws of thermodynamics with the honorverse.

For example, that super stealth recon drone the RMN is so fond of has an unshielded fusion reactor that emits vast amounts of radiation. That's energy, depositing itself in the structure of the the drone. What happens when you pour energy into a physical object?

If the reactor is to dangerous for humans to be near, that means it is radiating large amounts of gamma rays and/or neutrons. I don't suppose there is any way that you could detect a gamma ray or neutron source or the increase in temperature caused by the structure of the ship absorbing some of this vast amount of radiation that is pouring through it?

ThinksMarkedly wrote:That's what I thought too. If it were possible to block the radiating with something that easily, it would have been done. Consequently, the fact that it wasn't means it can't be done (or no one has come up with a way to do so).

The other danger is that if each ship is radiating in the direction of the other, they're effectively bathing each other in warmth, which means those ships will be warmer than the interplanetary medium.

kzt wrote:There is a whole lot of issues with the laws of thermodynamics with the honorverse.

For example, that super stealth recon drone the RMN is so fond of has an unshielded fusion reactor that emits vast amounts of radiation. That's energy, depositing itself in the structure of the the drone. What happens when you pour energy into a physical object?

If the reactor is to dangerous for humans to be near, that means it is radiating large amounts of gamma rays and/or neutrons. I don't suppose there is any way that you could detect a gamma ray or neutron source or the increase in temperature caused by the structure of the ship absorbing some of this vast amount of radiation that is pouring through it?

I know that you have mentioned this before and I mostly agree.

One quibble is that a reactor can be "dangerous for humans to be near", without necessarily "radiating large amounts of gamma rays and/or neutrons". I agree that it must be radiating some multiple of the background radiation, but do not know if that has been quantified.

We know that the preferred detectors are not the ones that search for light speed sources. Honor's attack at Hades would have been disastrous if people had been monitoring the right sensors. The incident with the Ghosts stated that all navies try to radiate heat away from enemy ships.

The system's greatest weakness was that it couldn't give complete coverage. Like any stealth system, it still had to deal with things like waste heat, for example. Current technology could recapture and use an enormous percentage of that heat, but not all of it, and what they couldn't capture still had to go somewhere. And, like other navies' stealth systems, the MAN's dealt with that by radiating that heat away from known enemy sensors. Modern stealth fields could do a lot to minimize even heat signatures, but nothing could completely eliminate them, and stealth fields themselves were detectable at extremely short ranges, so any ship remained vulnerable to detection by a sufficiently sensitive sensor on exactly the right (or wrong) bearing.

David has stated that it emits so much radiation that it can't be shielded for use on a LAC or a huge assault shuttle. This isn't putting the reactor under the seats, it means you can't put it on the far end of the spacecraft with the entire ordinance bay and engineering systems acting as shielding and not poison the crew. How much radiation does this take, in the honorverse?

The US was able to shield a nuclear reactor on an airplane in the 1950s. The honorverse has thousands of years experience with radiation shielding fusion reactors and spacecraft. So, if you can't shield it then it is putting out a LOT of radiation.

In that case, sorry to have doubted you.

Insanely, the airplane had a fission reactor. According to Wikipedia, the shielding problem was not completely solved (particularly in case of a crash):

One inadequately solved design problem was the need for heavy shielding to protect the crew and those on the ground from acute radiation syndrome; other potential problems included dealing with crashes

tlb wrote:In that case, sorry to have doubted you.

Insanely, the airplane had a fission reactor. According to Wikipedia, the shielding problem was not completely solved (particularly in case of a crash):

One inadequately solved design problem was the need for heavy shielding to protect the crew and those on the ground from acute radiation syndrome; other potential problems included dealing with crashes

The ground crew was the major problem. The designers didn't even try to fully shield the reactor within the plane (couldn't have taken off if they had)-- they simply restricted the crew to the forward area around the cockpit and stuck a radiation shield just aft of the crew area. So only radiation going directly forward was blocked.

To the top, bottom, sides, and rear there was no radiation shielding. Now, enough air will provide shielding; so it's not like they'd be cooking folks on the ground as they few overhead; but it would have made performing maintenance and loading weapons tricky.

And a crash would be a pretty major radiation incident

Jonathan_S wrote:To the top, bottom, sides, and rear there was no radiation shielding. Now, enough air will provide shielding; so it's not like they'd be cooking folks on the ground as they few overhead; but it would have made performing maintenance and loading weapons tricky.

Which would be the opposite problem for a drone meant to be stealthy. It's probably got a radiation sink that soaks up as much as it can so as little as possible leaks out of the hull and radiates. It will probably also channel the leakage alongside the heat output to a specific direction that it can control.

But that means the insides of that drone are glowing green with radiation. Servicing such a thing after use, like the nuclear aeroplane, could be hazardous. They probably need to remotely clean it and dump the radiation sink overboard (if that's not considered littering).

This can probably be solved for manned ships, but it might be impractical. They would need to step down the reactor, increase its size, add shielding and distance, etc. That increases the size and mass of the ship, at which point it's no longer worth having it instead of whatever they use in LACs.

ThinksMarkedly wrote:
This can probably be solved for manned ships, but it might be impractical. They would need to step down the reactor, increase its size, add shielding and distance, etc. That increases the size and mass of the ship, at which point it's no longer worth having it instead of whatever they use in LACs.

Tons of 95% uranium 235. And many tons of shielding, as many gigawatts of power generates quite a bit of neutrons.

Jonathan_S wrote:To the top, bottom, sides, and rear there was no radiation shielding. Now, enough air will provide shielding; so it's not like they'd be cooking folks on the ground as they few overhead; but it would have made performing maintenance and loading weapons tricky.

ThinksMarkedly wrote:Which would be the opposite problem for a drone meant to be stealthy. It's probably got a radiation sink that soaks up as much as it can so as little as possible leaks out of the hull and radiates. It will probably also channel the leakage alongside the heat output to a specific direction that it can control.

But that means the insides of that drone are glowing green with radiation. Servicing such a thing after use, like the nuclear aeroplane, could be hazardous. They probably need to remotely clean it and dump the radiation sink overboard (if that's not considered littering).

This can probably be solved for manned ships, but it might be impractical. They would need to step down the reactor, increase its size, add shielding and distance, etc. That increases the size and mass of the ship, at which point it's no longer worth having it instead of whatever they use in LACs.

But that would only be true of the drone after first use; the fusion reactor only produces radiation when it is running, unlike a fission reactor. Also unlike missiles that are expected to explode at the end of their first use, drones might have radiation shielding to protect reusable modules (the instrumentation and the drives) and just swap out the reactor and the fuel tanks, which can be used to provide spacing.

The radiated pieces can be shot into a convenient star or gas giant, to get them out of the way.

Jonathan_S wrote:The ground crew was the major problem. The designers didn't even try to fully shield the reactor within the plane (couldn't have taken off if they had)-- they simply restricted the crew to the forward area around the cockpit and stuck a radiation shield just aft of the crew area. So only radiation going directly forward was blocked.

<snip>

The plan was also to use senior pilots who were beyond child bearing age to mitigate the effects of the radiation.