GT:ISW Combat with information Symmetry

[ak_aramis]

Anthony: most bodies in the ecosphere of a star are well below freezing - it's the atmosphere that retains much of the heat rather than immediate reradiation as blackbody - by reflection of the IR blackbody radiation. Keep in mind, 1m below surface, the moon is a near constant –35°C, or about 235 Kelvin.

LS pushes that up quite a bit: 40°C is noticeable.

(And remember - the backdrop is 3 Kelvin.)

[jason taylor]

Originally Posted by Anthony

Identification isn't really automatic, it's just that there tend to be very very few ship-like objects to get confused by. If you have a ship that's behaving like a rock, and is mixed in with a lot of other rocks, it can easily be mistaken for a rock. And no, life support will not make you more visible, at least if you're in the life zone -- an object the size of a scout ship is typically exposed to a few hundred kilowatts of sunlight, most of which will be absorbed and converted to heat, and adding another 0.1% for life support is not likely to exceed a noise level signal.

However, any planet without a ring system simply isn't likely to have enough rocks to be concerned with. The number of rocks in the Earth-Moon system that could be confused with a spaceship is zero.

That said, Traveller ambushes have never been dependent on stealth in space in the first place. Just sit at a place where someone is likely to exit jump, and when they exit jump, move to attack them. Typical targets aren't very fast in normal space and probably don't have enough fuel to jump out immediately, so they can't run away, and if for some reason they come in with a battlefleet, you have already refueled and can run.

True enough. I was thinking of the actual engagement and the need to have more complexity then slugging matches.

[Anthony]

Originally Posted by ak_aramis

Anthony: most bodies in the ecosphere of a star are well below freezing

A perfect blackbody (most asteroids are very close to black) at Earth's orbit must have a surface temperature of 278K (5C) to maintain a stable temperature.

Originally Posted by aramis

Keep in mind, 1m below surface, the moon is a near constant –35°C, or about 235 Kelvin.

The moon is large enough and rotates slowly enough that its internal temperature varies significantly with latitude, but despite that, my sources disagree. To get temperature of 238K, you'd need to be at 66 degrees.

[nik1979]

Originally Posted by Anthony

Identification isn't really automatic, it's just that there tend to be very very few ship-like objects to get confused by. If you have a ship that's behaving like a rock, and is mixed in with a lot of other rocks, it can easily be mistaken for a rock. And no, life support will not make you more visible, at least if you're in the life zone -- an object the size of a scout ship is typically exposed to a few hundred kilowatts of sunlight, most of which will be absorbed and converted to heat, and adding another 0.1% for life support is not likely to exceed a noise level signal.

However, any planet without a ring system simply isn't likely to have enough rocks to be concerned with. The number of rocks in the Earth-Moon system that could be confused with a spaceship is zero.

That said, Traveller ambushes have never been dependent on stealth in space in the first place. Just sit at a place where someone is likely to exit jump, and when they exit jump, move to attack them. Typical targets aren't very fast in normal space and probably don't have enough fuel to jump out immediately, so they can't run away, and if for some reason they come in with a battlefleet, you have already refueled and can run.

Detection time - i did some no. Regarding FLOPS and passmarks. i made assumptions based on 2012 multiplied by 10,000 and tried to get the frames per second. I assumed a cone from outer Sol limit at about 35" degrees with a length of the entire system. I used Kens article in atomic rockets and got 0.2-4fps if it was a medium comp at TL10 and 2-4fps in a microframe (or a server cluster). Ken says all you need to scan for first are hot and location near where you will be or moving to where youll be. This may dramatically increase prioritization and processing 100x or more. This means the computing power can easily update data ever 1/200-400 of a second. But the assumption needs to clear up if sensors have their own dedicated computers or it draws from the bridge.

In ship building one can add more servers or scale up the server clusters. Passive sensors generate a ton of heat if we assume computing heat per size (not heat per flops) has not been completely reduced.

[Anthony]

Originally Posted by nik1979

I assumed a cone from outer Sol limit at about 35" degrees with a length of the entire system.

Long range detection is of limited value in Traveller; due to jump, normal warning time for battles is less than an hour, so getting more than that (due to a normal-space approach) is just gravy.

[ak_aramis]

Originally Posted by Anthony

A perfect blackbody (most asteroids are very close to black) at Earth's orbit must have a surface temperature of 278K (5C) to maintain a stable temperature.

Most are not perfect blackbodies - an albedo of 0.1 drops that temp quite a bit (the low end for S and M types), and even 0.04 drops them to freezing for C-types. since the adjustment for albedo is under the radical... we can put the albedo under the same radical. we need an albedo of just over 0.07 to drop the temp of a C type down - a bright carbonaceous - but those aren't as common in the inner system. S and M types (sillicate and metalic) are all gointo to be typically below freezing. And the mean albedo of the moon, on a quick google, was 0.12 - sufficient that it should average below freezing.

Put a spacecraft in orbit, and lose power, your problem isn't cooling it off, it's keeping it from getting too cold. See also Apollo 13 (albeit its Albedo was something ludicrously high).

Asteroidal type distribution outside the main belt seems to be pretty much burried behind paywalls. NASA's report on deflection notes the second peak in the PHO (Potentially Hazardous Object) population as albedo 23%... and the modal peak as 7%. Which is, at earth orbit, freezing ±1°.

[Anthony]

Originally Posted by ak_aramis

Most are not perfect blackbodies - an albedo of 0.1 drops that temp quite a bit

If visual albedo is 0.1 and IR albedo (emissivity) is 0.0 (usually IR albedo is also non-zero), it reduces equilibrium temperature from 278 to 270, which is detectable but hardly on the scale you're talking about. To reduce it from 278 to 238, you'd need a visual albedo of 0.47. In any case, you seem to be making the assumption that a life support compartment at 288K implies a hull temperature of 288K, which is completely unjustified.

[ak_aramis]

Originally Posted by Anthony

If visual albedo is 0.1 and IR albedo (emissivity) is 0.0 (usually IR albedo is also non-zero), it reduces equilibrium temperature from 278 to 270, which is detectable but hardly on the scale you're talking about. To reduce it from 278 to 238, you'd need a visual albedo of 0.47. In any case, you seem to be making the assumption that a life support compartment at 288K implies a hull temperature of 288K, which is completely unjustified.

actually, it implies not only a 288K capsule temp, but also usually some power source well above 288K. If the power system is off, you're going to want a 285-295K onboard temperature in all habited areas. Without a power source, and without gravity, you don't get convection, so you don't get thermal cycling, but you still get conduction and will have a mean surface temp of 288k. If not rolling, that's going to be some 300K+ on the hot face and 250K- on the cold... Lacking powered heat pumps, and external convective and conductive cooling, the radiant signature has to be the same as the desired ambient temp.

Ships in or beyond the ecosphere are visually above the temp of asteroids in the same regimes. You can hide behind them, but beside them is not a viable option except against the most inept or ill equipped ships.

Of course, merchant often does equate to ill equipped and/or inept...

[nik1979]

Open for Critique

Ways to Ambush or Trap

• from inside the ship: a hi-jacking
• Forging Ship IFF and if the ship can matches XX% (OTU standard) of the profile.
• In a high density field: a high yielding mineral belt or ring. The idea is dense enough to give mass detection a hard time finding hollowed out asteroids. Using concealed passive sensors and probably intercepted Intelligence of movement.
• In a Gass Giant with a low enough G for the ship to accelerate towards its target. Same as High density field. Ex. Neptune and special equipment to allow personnel to lie in wait.

Affect on doctrine

• Q-ships will be very very close to normal Merchant ships*.
• Merchant ships will try to be very much like known Q-ships
• Q-ships may be the majority of fighting ships
• Modular Ships that can economically modified for Q-ship or Merchant ship.
• War Ships are unmistakable, some technologies and doctrines will allow for "power projection".
• Less Expansionist or non-Imperial Navies will have an fleets of Q-ships; constantly hiding their true numbers.
• Drones are employed heavily to saturate systems and can quickly make a Merchant ship dangerous as a Drone Carrier. Drones in the form of Ships to Missile Pods, to Laser Firing Missiles.
• Stations are more secure because of the lead distance they have on arriving ships. Fleets jumping in system may find the Stations and Fortresses moving for cover. Stations would have anchored multiple celestial covers - grabbing several large asteroids and mounting unmanned m-drives and sensor and weapon platforms.
• Systems with Rich Asteroids are the most naturally defensible systems. Thus more valuable for Independent "States".**

*A lot of Beowulf/Hero, Far-Trader, Akkigish/Fat-Tader Q-ships, 2k-10K-ton Freighers and Liners Q-ships. Might as well shorten them as Q-hero, Q-Fat Trader?
** High Trade, but Highly Independent or Autonomous states with few resources. They can vary from Raiding and Trading states like Dark-ages Danes or something like Singapore or Taiwan.

[Anthony]

Originally Posted by ak_aramis

actually, it implies not only a 288K capsule temp, but also usually some power source well above 288K.

Not really. It's questionable how far you can throttle a fusion plant down, but Traveller seems to have pretty good batteries.

Originally Posted by ak_aramis

Without a power source, and without gravity, you don't get convection, so you don't get thermal cycling, but you still get conduction and will have a mean surface temp of 288k.

No you won't. You'll have a mean surface temperature that results in net heat loss through the hull equal to the power output of internal systems. It will typically be necessary to have some insulation around the habitable parts of the ship, but that's true anyway.