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Old 09-16-2020, 12:52 AM   #1
Pectus Solentis
 
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Default [Spaceships 1] How much are IR Signature of Reactionless Drives?

At pp44-pp45, IR signatures of Reaction Drives and Power Plants are described, but there are no description for IR signatures of Reactionless Drives, and I couldn't find that on the entire books of Spaceships 1...
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Old 09-16-2020, 01:14 AM   #2
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

It totally depends on your chosen technobabble explanation for reactionless drives. So ask your GM, or if you are the GM, choose.
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Old 09-16-2020, 01:25 AM   #3
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

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Originally Posted by Taneli View Post
It totally depends on your chosen technobabble explanation for reactionless drives. So ask your GM, or if you are the GM, choose.
Well. thanks.
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Old 09-16-2020, 01:32 AM   #4
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

'Hot' Reactionless Engines are noted (p.24) as having a waste-heat signature equivalent to a conventional drive's exhaust. I take that to mean +5, like a chemical rocket.

Standard Reactionless Engines have no mention, but would presumably have less signature than a hot drive. I go with +4, so they give more signature than just auxiliary power, but less than a hot drive.

This also means that hot drive negate stealth, but standard ones don't (so a high performance spacecraft with standard drives is, in my setting, generally suspected of being a spy vessel or the like). It also means that if you power your hot drive with an MHD plant you can be a little bit stealthy compared to all those hot glowing ships with their fusion plants.

It also means that civilian vehicles (like flying cars) are probably limited to standard reactionless drives when in congested airspace, landing around built-up areas, and so on.
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Old 09-16-2020, 01:38 AM   #5
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

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Originally Posted by Rupert View Post
'Hot' Reactionless Engines are noted (p.24) as having a waste-heat signature equivalent to a conventional drive's exhaust. I take that to mean +5, like a chemical rocket.

Standard Reactionless Engines have no mention, but would presumably have less signature than a hot drive. I go with +4, so they give more signature than just auxiliary power, but less than a hot drive.

This also means that hot drive negate stealth, but standard ones don't (so a high performance spacecraft with standard drives is, in my setting, generally suspected of being a spy vessel or the like). It also means that if you power your hot drive with an MHD plant you can be a little bit stealthy compared to all those hot glowing ships with their fusion plants.

It also means that civilian vehicles (like flying cars) are probably limited to standard reactionless drives when in congested airspace, landing around built-up areas, and so on.
Well, quite reasonable. Thanks very much.

Last edited by Pectus Solentis; 09-16-2020 at 01:41 AM.
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Old 09-16-2020, 06:51 PM   #6
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

Absent any outputs specific to the device's technobabble (like the heat for Hot Reactionless), reactionless drives would likely generate minimal heat. I'd just disregard them as whatever is generating the energy is most likely putting out more waste heat than the drives would. Of course, for SS1 power plants, this is indistinguishable from treating such drives as +4 (as high-energy systems, they aren't usable on auxiliary power, so you need at least a +4 power plant running to be able to use them).
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Old 09-16-2020, 09:14 PM   #7
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

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A this is indistinguishable from treating such drives as +4 (as high-energy systems, they aren't usable on auxiliary power, so you need at least a +4 power plant running to be able to use them).
.....until you go to Book 7. :)

The output of a Zero Point Energy unit would depend on the technobabble but for the really weird ones like orgone or psi the thermal signature might be very low indeed. Or whatever the life support for a group of psis or an open space full of trees amounts to.

If you could build a Perpetual Motion Engine at all you could probably build one that operated at cryogenic temperatures. Then you use superconducting wiring to distribute the power so there are no transmission losses.

In other words, if you have a license to violate the Laws of Physics you might as well try and find out the absolute limits of how far it stretches.
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Old 09-17-2020, 07:30 AM   #8
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

IR signatures are generated by energy sources which a reactionless drive is not. A "Hot" drive is merely inefficient; part of the energy provided to it was wasted as thermal rather than directed kinetic energy. Unless otherwise noted, a system that is not officially listed as having an IR signature doesn't.
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Old 09-18-2020, 12:39 AM   #9
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

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IR signatures are generated by energy sources which a reactionless drive is not. A "Hot" drive is merely inefficient; part of the energy provided to it was wasted as thermal rather than directed kinetic energy. Unless otherwise noted, a system that is not officially listed as having an IR signature doesn't.
Actually, the hot drives are more efficient - they produce double the thrust per unit of power. That suggests that there's an expensive but energy-efficient way of producing reactionless thrust that happens to also make space behind the ship really hot. The less efficient way is cheaper, but seems to dump waste heat elsewhere or uses an entirely different principle that doesn't produce waste heat.
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Old 09-18-2020, 12:59 AM   #10
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Default Re: [Spaceships 1] How much are IR Signature of Reactionless Drives?

In practice, any system that doesn't actively generate power is unlikely to produce a signature that's meaningfully larger than the power plant, though in some cases it may be incompatible with stealth.
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