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Topics Enjoying 30 Years of Discussion

Xboats - Originally Broken

The Xboat is a gee-whiz invention of early classic Traveller: a starship with no power plant. This was allowed in the earliest rules, but was quickly changed.

It was not allowed under LBB2'77:
The Engineering Section: Each starship is fitted with a power plant (to provide internal power and power for the maneuver drive), a maneuver drive (for interplanetary travel), and a jump drive (for interstellar jumps). Each is essential to the definition of a starship.

They did it anyway, since some Referee liked it, as is the usual way of RPGs.

Just like they did with the Modular Cutter; there is no CT rule-set that allows [edit: nor disallows] the design of a modular spacecraft, yet they did it anyway (presumably copying the TV series). Somehow no-one complains about the Cutter, though...
 
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Which is easy to do if you're a Vargr "corsair", and somewhat less easy if you're living near the apex of Zho and Imp space, but still doable. Just find a freeport and open your cargo bay ... weapons drawn of course.
Who's leaving these freeports open? Why have the authorities not shut it down? What officer of the government is shielding it? In the Imperium, I believe, you can do what you want with your world, but start messing with shipping and Navy shows up. And it's my understanding, they're not known for being subtle nor a light touch.
 
Black Globe

It does not mnake you undetectable, as Black Holes are not. You cna be detected because of the "hole" you leave in the background. And once tedected, if at firing range, you're dead (no possibility to avoid fire, your energy sinks would fill quite quickly, and you'd have not detected enemy closing)

Power Plant shutdown (meaning EP=0) and sustain the crew on battery power while silent running with transponder OFF

How do you hide you heat signature against detection by simple IR detector? Space is cold, and your ship would shine like a star on IR.
 
How do you hide you heat signature against detection by simple IR detector? Space is cold, and your ship would shine like a star on IR.
I'm reminded of the Refrigeration Laser concept explored in the book Sundiver written by David Brin in 1980 that works the same way as a food refrigerator does in TL=6+ homes.

Sundiver.jpg


Project Icarus it was called, the fourth space program of that name and the first for which it was appropriate. Long before Jacob's parents were born—before the Overturn and the Covenant, before the Power Satellite League, before even the full flower of the old Bureaucracy—old grandfather NASA decided that it would be interesting to drop expendable probes into the Sun to see what happened.

They discovered that the probes did a quaint thing when they got close. They burned up.

In America's "Indian Summer" nothing was thought impossible. Americans were building cities in space—a more durable probe couldn't be much of a challenge!

Shells were made, with materials that could take unheard of stress and whose surfaces reflected almost anything. Magnetic fields guided the diffuse but tremendously hot plasmas of corona and chromosphere around and away from those hulls. Powerful communications lasers pierced the solar atmosphere with two-way streams of commands and data.

Still, the robot ships burned. However good the mirrors and insulation, however evenly the superconductors distributed heat, the laws of thermodynamics still held. Heat will pass from a higher temperature to a zone where the temperature is lower, sooner or later.

The solar physicists might have gone on resignedly burning up probes in exchange for fleeting bursts of information had Tina Merchant not offered another way. "Why don't you refrigerate?" she asked. "You have all the power you want. You can run refrigerators to push heat from one part of the probe to another."

Her colleagues answered that, with superconductors, equalizing heat throughout was no problem.

"Who said anything about equalizing?" the Belle of Cambridge replied. "You should take all excess heat from the part of the ship were the instruments are and pump it into another part where the instruments aren't."

"And that part will burn up!" one colleague said. "Yes, but we can make a chain of these 'heat dumps,'" said another engineer, slightly more bright. "And then we can drop them off, one by one ..."

"No, no you don't quite understand." The triple Nobel Laureate strode to the chalkboard and drew a circle, then another circle within.

'Here!" She pointed to the inner circle. "You pump your heat into here until it is, for a short time, hotter than the ambient plasma outside of the ship. Then, before it can do harm there, you dump it out into the chromosphere."

"And how," asked a renowned physicist, "do you expect to do that?"

Tina Merchant had smiled as if she could almost see the Astronautics Prize held out to her. "Why I'm surprised at all of you!" she said. "You have onboard a communications laser with a brightness temperature of millions of degrees! Use it!"

Enter the age of the Solar Bathysphere. Floating in part by buoyancy and also by balancing atop the thrust of their refrigerator lasers, probes lingered for days, weeks, monitoring the subtle variations at the Sun, that wrought weather on the Earth.
Basically you need to point a refrigeration laser into space away from the sensors you're wanting to avoid being detected by. Everything after that is heat pumps and load balancing on the engineering side of things to reduce your IR signature below the threshold of detection by the sensors you're wanting to evade (insert engineering handwavium here).

Obviously the application we're talking about here is one of low temperature (under 400º Kelvin) rather than solar chromosphere plasma millions of degrees kelvin, so the engineering will be slightly different but the principles of physics are still largely the same ... the only difference is a matter of degrees (if you'll pardon the pun). ;)

In the specific application being discussed here, you would want that refrigeration laser to operate below EP=0 (so basically a "low power laser" by starship weapon standards) that could be run on battery power rather than on fusion power for the "stealth duration" needed for a "stealth drift fighter" to coast past its launch point and fire off its missile batteries (presumably as a "lightning strike" single attack before drifting out of range, mitigating retaliation efforts).
 
Won't work.

The laser will heat up hydrogen, dust etc in the direction it is pointing which will then radiate in every direction - easily detectable.
 
When is a vacuum not a vacuum?
When it's inconvenient for an argument on the forums!
space is never a vacuum. just really, really close.

A vacuum is defined as a space devoid of all matter. In the Solar System, space contains on average five atoms per 1cm3. Interstellar space, between stars, contains around one atom per 1cm3, while intergalactic space, between galaxies, contains 100 times less. Ultimately, a perfect vacuum isn’t possible because quantum theory dictates that energy fluctuations known as ‘virtual particles’ are constantly popping in and out of existence, even in ‘empty’ space.

From https://www.sciencefocus.com/space/is-space-a-perfect-vacuum/
 
When is a vacuum not a vacuum?
When it's inconvenient for an argument on the forums!
Space isn't a vacuum - your point? Your laser has to be powerful enough to bleed off the waste heat from a multi gigaWatt fusion reactor, it will thus be energetic enough to heat up the hydrogen and other dust that is present in every cubic metre of space. As the laser beam diverges it will heat up even more hydrogen and dust leaving an easily detectable trail that can be tracked back to its point of origin in microseconds if not faster.

Look, I get it, everyone thinks they can come up with a clever way to get stealth in space.

Without magic heat sinks, you can't.
 
Your laser has to be powerful enough to bleed off the waste heat from a multi gigaWatt fusion reactor
That I specified very deliberately and specifically will be EP=0 turned off cold for the duration of the "stealth drift" into firing position so as to not be emitting neutrinos that would be picked up on neutrino sensors available at TL=10+.
There's a reason why I kept mentioning battery power and needing to build the fighter to still operate at EP=0 (meaning missile weapons and model/2 computer maximum under CT rules) using no maneuver drive during the coasting into firing position duration.

Try again.

Also, why are people assuming that the interior of a stealth drift fighter would be kept at shirtsleeves environment pressure and temperature? Why wouldn't the crew be wearing vacc suits with the craft operating on REALLY low power while drifting with the power plant turned off and only battery power available? Basically, let the ship cool down (presumably in the shadow of its mothership) before launching it on its trajectory from which it will make its attack run.

Essentially, the space equivalent to an armed glider so as to minimize the signature.
 
The reality of space combat would probably be like Jutland, spend too much on a fleet to actually risk it getting destroyed, no matter how good it is. Or like the pacific, an example I used IMTU, one power sits back and out produces the other, coming in with such overwhelming numbers where even 1:1 losses are a win.
 
The Germans had decided on building up a risk fleet, and preserve it by being a fleet in being.

Willi never really appreciated the strategic hole he dropped his country into by nurturing his and his enablers' naval ambitions.
 
Who's leaving these freeports open? Why have the authorities not shut it down? What officer of the government is shielding it? In the Imperium, I believe, you can do what you want with your world, but start messing with shipping and Navy shows up. And it's my understanding, they're not known for being subtle nor a light touch.
That, good sir, is the premise of an LBB adventure :)(y)
 
that works the same way as a food refrigerator does in TL=6+ homes.

So, I guess it cools your ship to near 0 K...

Of course, this would probably freeze any fluid from your ship, many mobile parts, Hydrogen fuel (so not allowing it to be used as fuel), etc...

And, even if the above problems were not enough, your crew would need to use vacc suits, with the degraded performace this means...

And even so, if even some degrees above 0 k, it would probably be detected.
 
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What do you mean with this?
It's his way.

The fundamental point of "cooling" anything is that you have to move the heat somewhere. The back of a refrigerator is typically warm as it removes heat from inside the cabinet.

So, while the ship is cooling to 0, that heat has to go somewhere, while you can't detect something that IS 0 degrees, you can detect something that is cooling DOWN to 0 degrees.
 
It's his way.

The fundamental point of "cooling" anything is that you have to move the heat somewhere. The back of a refrigerator is typically warm as it removes heat from inside the cabinet.

So, while the ship is cooling to 0, that heat has to go somewhere, while you can't detect something that IS 0 degrees, you can detect something that is cooling DOWN to 0 degrees.
Ah, what you're saying is what's detectable is the heat they're shedding (away from your sensor) but only through its reflection/re-radiation from particles behind it.
 
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