[Spaceships] Force Screen (Energy Variant) vs. Radiation?

[DaltonS]

Force Screen Variants
...
"Energy: Only protects against beam weapons (or energy melee weapons like force swords), radiation, and the burning damage of nuclear or antimatter blasts."

GURP Spaceships page 32

1. What sort of PF (Protection Factor) does this Energy variant offer against radiation in space as described on page 40-41 of GURP Spaceships 5: Exploration and Colony Spacecraft?
2. Does the general Force Screen (SS1 p16) provide any radiation protection?
3. Can the Drive Field design switch (SS1 p31) provide any radiation protection with or without the Energy Variant switch?

I'm thinking of using the invention of a "radiation screen" as the new starting point to my Hyperverse tech sequence (radiation screen => hyperdynamic field grid => reactionless drive => "hypersink" cloaking => jump gate to hyperspace => hyperjump stardrive). I just have to link the "hyper-factor" to the "hyperlimit" I use in my hyperspace rule set.

Dalton "who thinks 30 kSPF sunscreen isn't going to cut it" Spence

[Fred Brackin]

Originally Posted by DaltonS

1. What sort of PF (Protection Factor) does this Energy variant offer against radiation in space as described on page 40-41 of GURP Spaceships 5: Exploration and Colony Spacecraft?
2. Does the general Force Screen (SS1 p16) provide any radiation protection?
3. Can the Drive Field design switch (SS1 p31) provide any radiation protection with or without the Energy Variant switch?

The force screens in UT provide PF equal to their DR.

If subjected to a "burn ex rad" the radiation received is based off of the final damage taken and you get your radiation protection that way.

[DaltonS]

Originally Posted by Fred Brackin

The force screens in UT provide PF equal to their DR.

So each dDR provides a PF of 10? That begs the question, just how strong is a "drive field"?

"The GM may rule that any reactionless engine is also a low-powered force screen at no extra power cost."

GURPS Spaceships, page 31

Note it says "low-powered" (not "light") and I have a hard time believing that the dDR of a Rotary Reactionless drive field (0.1G) should be equal to that of a Super Reactionless or Subwarp one (50/100 and 500 Gs respectively). Would multiplying the field's dDR by the drive's sAccel in Gs be appropriate?

Dalton "who hopes someone will field this question" Spence

[sir_pudding]

Originally Posted by DaltonS

Would multiplying the field's dDR by the drive's sAccel in Gs be appropriate?

It probably depends on the specific handwave but sure that gives a reasonable range and seems to do what you want. Although you might want to multiply it by the absolute value of log(thrust) or some other function so that you don't have Subwarp fields that are 5000 times stronger than rotary drive fields.

[Fred Brackin]

[QUOTE=DaltonS;1071007]So each dDR provides a PF of 10? That begs the question, just how strong is a "drive field"?/QUOTE]

The answer to the first question is "yes".

The answer to the second question is probably "GM's call".

To my understanding, Spaceships was not intended to be comprehensive technological supplement. It's a quick and dirty 5% margin of error generator of basic stats plus combat system.

People seem to keep trying to squeeze more detail out of it than it was ever intended to deliver.

[Crakkerjakk]

Originally Posted by DaltonS

That begs the question, just how strong is a "drive field"? Note it says "low-powered" (not "light") and I have a hard time believing that the dDR of a Rotary Reactionless drive field (0.1G) should be equal to that of a Super Reactionless or Subwarp one (50/100 and 500 Gs respectively). Would multiplying the field's dDR by the drive's sAccel in Gs be appropriate?

Dalton "who hopes someone will field this question" Spence

I'd treat each drive system as one system of light force screen as light/low-powered are interchangable to me. I wouldn't worry that different types of reactionless drives have different thrust, because IMO you're unlikely to have multiple types in one setting anyways, and it's all handwaving anyways how they work.

[DaltonS]

Originally Posted by Crakkerjakk

I'd treat each drive system as one system of light force screen as light/low-powered are interchangable to me. I wouldn't worry that different types of reactionless drives have different thrust, because IMO you're unlikely to have multiple types in one setting anyways, and it's all handwaving anyways how they work.

One way I can see having multiple reactionless drive field types would be a setting where star travelling races with different TL backgrounds meet. One might use Rotary drives, another could use Standard ones, a third might use Subwarp, etc..

Another question about Cosmic Rays...

"Galactic cosmic rays are charged particles (atomic nuclei, electrons, positrons, etc.) that originate beyond the solar system, traveling through space at near-light speeds. Their high energy is difficult to shield against; they smash through matter, leaving a train of ionized atoms that kill living cells."

GURPS Spaceships 5: Exploration and Colony Spacecraft, page 40

On one hand, as high energy particles they have a PF divisor of 100 against mass shielding. On the other hand, planetary and solar magnetic fields seem to deflect them. Where would force screen dDR fit in with this? Would a "Cosmic" powered screen be more effective?

Dalton "who always has another question" Spence

[Crakkerjakk]

Originally Posted by DaltonS

One way I can see having multiple reactionless drive field types would be a setting where star travelling races with different TL backgrounds meet. One might use Rotary drives, another could use Standard ones, a third might use Subwarp, etc..

The race with the 500g acceleration is going to find everyone and their mother wants their technology. Sooner or later it's what everyone will be using.

Originally Posted by DaltonS

Another question about Cosmic Rays...On one hand, as high energy particles they have a PF divisor of 100 against mass shielding. On the other hand, planetary and solar magnetic fields seem to deflect them. Where would force screen dDR fit in with this? Would a "Cosmic" powered screen be more effective?

Dalton "who always has another question" Spence

I'd allow a screen to be immune to the divisor.

[Fred Brackin]

Originally Posted by DaltonS

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Another question about Cosmic Rays...On one hand, as high energy particles they have a PF divisor of 100 against mass shielding. On the other hand, planetary and solar magnetic fields seem to deflect them. Where would force screen dDR fit in with this? Would a "Cosmic" powered screen be more effective?

Dalton "who always has another question" Spence

The planetary magnetic fields don't deflect cosmic rays sharply but the Earth;s magnetopause is always at least 10,000 miles from the earth's surface and a few degrees count more over a long distance.

Besides the distance thing these amgnetic fields aren't very intense. They do better against low energy solar flare particles but it's the miles and miles of atmosphere that provide most of the protection from cosmic rays.

Add this up and it means that the subject is basically irrelevant to Spaceships force fields.

Comparing things that Spacehips is meant to handle like particle beams even these get a (5) armor divisor and individual particle energy in beams is assumed to be much lower than the cosmic ray ranges.

Still, I can't tell you how many dice of damage a single cosmic ray is meant to do. Probably zero. If you treat each ray particle as an individual attack probably nothing gets through.

The real answer though is that Spaceships isn't meant to address these questions.