[Spaceships] of the Solar Patrol
 

The recently published Tales of the Solar Patrol has drawn me out of lurker-dom and into actually posting on these forums, which I have been anonymously following for quite some time. (If you haven't bought that PDF yet and have any interest in pulp sci-fi, click on that link pronto - you won't be disappointed.)

As was mentioned in a previous thread on the setting, GURPS Spaceships write-ups for the various ships would make a fine addition to Tales of the Solar Patrol. At first glance, I thought it would be a fairly simple affair. After all, the ships are described in a fair amount of detail. I realized that matters were much more complicated when I looked at it more closely, however.

Hence this thread, in which I will create conversions (and possibly some new designs) and discuss my thinking along the way. Although my enthusiasm for all things GURPS is boundless, I don't have a lot of practical experience yet, so feedback would be appreciated.

Now, with all that intro out of the way, I will proceed to the first step - figuring out workable stats for the miraculous Electron Drive. One caveat: I realize that the Tales of the Solar Patrol rules were not written with hard realism in mind - ships move "at the speed of plot", etc. Still, I like a bit more crunchiness in my games, so I'm shooting for a middle ground between total hand waving and meticulously plotting out Hohmann transfer orbits, while still staying as close as possible to the feel of the setting.

OK, on to the Electron Drive. The text is wildly contradictory regarding its specifications. On the one hand, it claims a maximum velocity of .1c with 1-2G acceleration. I checked the travel times in Tales of the Solar Patrol against the equations and distances listed on pp.39-40 of GURPS Spaceships - results are wildly different. At .1c, even the maximum distance to Jupiter could be covered in under 4 days (I will admit that I did some simplification in my calculations and assumed straight line minimum and maximum distances between planets, not hyperbolic transfer orbits).

It seems to me that the travel times listed are more integral to the setting - they give the Solar System a more immense, isolated feel. OK, some more playing with numbers revealed an average velocity, for the travel times given, of .0008c. All right, let's round that off to .001c. Some more number crunching gives us (roughly) the following travel times:

Earth to Mercury: 4 - 8 days
Earth to Venus: 2 - 10 days
Earth to Mars: 3 - 15 days
Earth to Belt: 10 - 21 days
Earth to Jupiter: 24 - 36 days

Not too bad. On average, these travel times are within about 25% of the values given in the book. The discrepancy could be accounted for by more realistic transfer orbits. Not sure which set of numbers I'll use - either seems reasonable to me. Perhaps a very good Astronavigation roll could allow the crew to pick the more favorable travel time.

The tables give the acceleration of various vessels 1-2 G acceleration. That seems a bit low, given that the text says that an Electron Drive ship can reach maximum velocity within an hour. Another quick calculation reveals that to hit even .001c in an hour would require an acceleration of 8.3G. Again, let's round it to 10G for neatness' sake.

Finally, some of the spacecraft seem to have half the performance of others . It would make the most sense to assume that the difference is 1 vs. 2 engines.

Taking all this into account gives the following:
Electron Drive (TL 6+3^)[Rear!]: Each engine gives 5G acceleration, with a maximum speed of .0005c. Performance can be enhanced as per p. 32 of Tales of the Solar Patrol.
Cost: Until I analyze the costs of the example ships more closely, I'm going with the assumption that the cost is the same as for the Standard Reactionless Drive.

As long as I'm at it, I'll throw in my guess at what the Tesla Coils are like. Treat them as a Total Conversion Power Plant, with the added note that they are ineffective more than 6 AU from the sun.

MORE TO COME

Re: [Spaceships] of the Solar Patrol
 

Hey, thanks for all the work. I hadn't begun all the number-crunching, I'm quite happy to let you do all that.

One suggestion, by genre convention the rear of a ship is usually dominated by the rocket tubes. If I'm reading right, I'd cut the acceleration by half or so, so that electron drives take up the majority of the rear location. All but the lifeboat (IIRC) have "2G" acceleration, so if you set the electron drive acceleration to 2.5g, it would require 4 slots leaving two slots for stern-chaser weapons. At 2G per drive, that would take 5.

Re: [Spaceships] of the Solar Patrol
 

That's okay. You don't use elliptical transfer orbits when you have a ship capable of constant acceleration or delta-vee comparable with solar orbit velocity (18.5 miles per second in the vicinity of Earth, 0.0001 c). In those cases you use hyperbolic orbits. And with the sort of velocities we are talking about in Tales of the Solar Patrol the hyperbolas are pretty flat.

Re: [Spaceships] of the Solar Patrol
 

tratclif: Interesting suggestion! I’ll keep that in mind when I start actually building the ships – see how it looks. Might make pricing a bit wonky, though.

Agamegos: Thanks for the correction. A mathematician I am not; I know just enough to know I know nothing.

************

Armoury & Weaponry
The biggest barrier in converting these systems is that the numbers given in GURPS Spaceships are in decade scale while those in Tales of the Solar Patrol are in the regular GURPS scale. My tendency will be to cleave more to the GURPS Spaceships way of doing things while adjusting the actual numbers to adhere as closely as possible to the relative performance of Tales of the Solar Patrol weapons and shields against one another.

The average Atomic Gun does 10dx5(4). Divide by 10 gives us 5d(4) damage, or somewhere in between 10 and 30 MJ output – let’s be generous and go with the higher number. Taking the Audie Murphy class patrol ship (SM +8) as a baseline and cross referencing 30 MJ with the Weapons tables in GURPS Spaceships would indicate that such weapons are merely secondary batteries (and wouldn’t even rate as tertiary batteries on the SM +11 Jovian Conqueror!).

It makes more sense (and seems to fit in with the ship descriptions) to assume that the Audie Murphy class’s weapons are major batteries. So let’s call it a 300 MJ weapon. I’ll have to play around with the sizes of batteries with some designs, but this seems to make sense in the context of their descriptions.

Next let’s look at the Nega-Barrier and armor. As a bit of an aside, it would appear that the Solar Patrol has an enormous tactical advantage, since only Solar Patrol vessels seem to be equipped with one (can an adventure dealing with the Jovian Overlord’s attempts to acquire this technology for his own be far off?). Fortunately for the forces of evil, all ships in this setting appear to have at least the minimal protection of armor.

A straightforward conversion of the SM +8 Audie Murphy class patrol ship’s DR 100 yields dDR of 10, which is in line with TL 9 Advanced Metallic Laminate armor. But bringing the main weapons in line with those in GURPS Spaceships involved a three-fold increase in damage. Should we do the same with the armor, making it more resemble TL 11 Diamondoid armor? Somehow, this feels wrong to me. For flavor reasons, I propose a compromise – let the ships of Jupiter have their superior armor, but restrict the Solar Patrol vessels to TL 9 (ok, 6+3) armor. This makes a somewhat interesting contrast between the two technologies.

<EDIT>On second thought, I think I'll have the Jovian Overlord's vessels use the same kind of armor, but just layer it on. </EDIT>

How about the Nega-Barrier? Divide by 10, multiply by 3? That yields dDR 165, quite a bit higher than the force screens listed in GURPS Spaceships. There are a couple ways to address this discrepancy. Once could create a new, lower powered, version, that yields, say, 50 dDR on a SM+8 vessel, but also use the partial screening design switch, creating three separate nega-barriers. Another possibility is to use the TL 11^ version, but with the Heavy Screen option – giving a dDR of 150. I like this option – it makes the potential for difficult tactical decisions; do we power the atom guns, nega-barrier, or electron drive?

Atomic Gun:
TL (6+3); Damage burn rad (4) (dDam 1); Range R3; Rcl 1

Hyper-focused Atomic Gun
TL (6+3); Damage burn rad (6) (dDam 1); Range R1; Rcl 1

Nega-Barrier (treat as TL 11^ Force Screen with adjustable switch, using Focus Nega-Barrier rules given on pg. 27 of Tales of the Solar Patrol)

Gravitic Vector (treat as both Artificial Gravity and Gravitic Compensators; price is same as either one).

OK, now the basic technology is squared away. Next up: some actual ship designs!

Re: [Spaceships] of the Solar Patrol
 

Here’s the first design, which I also used as the baseline for my conversion assumptions. Note that prices follow the guidelines in GURPS Spaceships, not Tales of the Solar Patrol. Since most of these ships are provided by government organizations and economics don’t seem to play a strong role in the setting, I’m not going to worry about it. If it really bugs anyone, I may look at readjusting the prices of some systems a bit.

Audie Murphy Class
Patrol Ship
TL (6+3^)

Front Hull
[1] Advanced Metal Laminate Armor (dDR 10)
[2-3!] Weapon – Major Battery (2 300 MJ Atomic Guns, fixed mount)
[4-6] Habitat (varies with ship assignment – typical configuration is: briefing room, captain’s office, crew lounge, mess hall, 2-person Science! lab, 2-person Sickbay, 4 2-person cabins, 2 1-person cabins, 2 VIP cabins)
[core] Control Room (4 workstations, C5 Infomat)

Central Hull
[1] Advanced Metal Laminate Armor (dDR 10)
[2!] Weapon – Major Battery (300 MJ Atomic Guns, fixed mount)
[3-4] Cargo Hold (100 tons)
[6] Hangar Bay (60 tons, launch 20 tons/minute)

Rear Hull
[1] Advanced Metal Laminate Armor (dDR 10)
[2] Science Comm/Sensor Array (Array Level 8)
[3] Tesla Coil Power Plant (provides 5 Power Points)
[4] Engine Room (1 workspace)
[5-6!] Electron Drive (each providing 5G acceleration, max speed .0005c
[core!] Nega Barrier (Heavy Screen; dDR 75/150; adjustable

Features:
Streamlined, wings, gravitic vector, carries 2 Lifeboats

PILOTING/TL 6+3 (HIGH-PERFORMANCE SPACECRAFT)
dST/HP 70; Hnd/SR 0/5; HT 13; Move 10G/.001c; LWt. 1000; Load 181; SM +8; Occ10+2 ASV; dDR 10; Cost $158.36M

Edit: converted two cargo bays to hangars for Lifeboats, noted Lifeboats in features.

Re: [Spaceships] of the Solar Patrol
 

Jovian Sky Scourer
Patrol Ship
TL (6+3^)

Front Hull
[1-3] Advanced Metal Laminate Armor (dDR 10 ea.)
[4!] Weapon – Spinal Mount (300 MJ Atomic Gun)
[5] Enhanced Comm/Sensor (Array Level 7)
[6] Control Room (C4 Infomat, Comm/Sensor 5, 3 Control Stations)

Central Hull
[1-3] Advanced Metal Laminate Armor (dDR 10 ea.)
[4-6] Habitat (4 bunkrooms, brig, 1 2-person cabin)
[Core!] Weapon – Spinal Mount (300 MJ Atomic Gun)

Rear Hull
[1-3] Advanced Metal Laminate Armor (dDR 10 ea.)
[4!] Weapon – Spinal Mount (300 MJ Atomic Gun)
[5-6!] Electron Drive (each providing 5G acceleration, max speed .0005c
[core!] Tesla Coil Power Plant (provides 5 Power Points)

Features:
Untreamlined, gravitic vector

PILOTING/TL 6+3 (HIGH-PERFORMANCE SPACECRAFT)
dST/HP 50; Hnd/SR 0/5; HT 12; Move 10G/.001c; LWt. 300; Load 16; SM +7; Occ10+4 ASV; dDR 30; Cost $31.9M

Re: [Spaceships] of the Solar Patrol
 

I took some major liberties with this one. Rather than extrapolating downwards to SM +3, I decided to make it SM +5. Since Habitats aren’t available, I decided that each bunk was the equivalent of a stabilized stretcher, taking up two seats. Since Total Life Support takes up double the number of cabins in a Habitat, it seemed reasonable that the “best air, food, and water recycling systems 21st-century technology can provide” would do the same, at the cost of a typical spaceship cabin.

Lifeboat
TL (6+3^)

Front Hull
[1] Advanced Metal Laminate Armor (dDR 5)
[2-6] Life Support (for 5)
[core] Control Room (C3 Infomat, Comm/Sensor 3)

Central Hull
[1] Advanced Metal Laminate Armor (dDR 5)
[2-6] Bunks (for 5)

Rear Hull
[1] Advanced Metal Laminate Armor (dDR 5)
[2-3] Cargo Hold (3 tons)
[4] Soft Landing System
[5] Engine Room (1 workspace)
[6!] Electron Drive (provides 5G acceleration, max speed .0005c)
[core] Fission Power Plant (provides 1 Power Point, 50 year endurance)

Features:
Untreamlined, gravitic vector

PILOTING/TL 6+3 (HIGH-PERFORMANCE SPACECRAFT)
dST/HP 20; Hnd/SR 0/4; HT 13; Move 5G/.0005c; LWt. 30; Load 3.5; SM +5; Occ 5 ASV; dDR 5; Cost $1.285M

Re: [Spaceships] of the Solar Patrol
 

I’m a little uncomfortable with the Defensive ECM and Fabricator on this. Defensive ECM seems a bit out of genre (but the description does mention decoys, which I could almost picture). The Fabricator would create munitions and spare parts while on extended combat missions.

Patton Class
Patrol Cruiser
TL (6+3^)

Front Hull
[1] Advanced Metal Laminate Armor (dDR 20)
[2!] Weapon – Major Battery (3 GJ Hyperfocused Atomic Gun, fixed mount)
[3-4] Habitat (100 cabins, 10-person sick bay, 2 crew lounges, briefing room, 3 offices, 1 Science! Lab)
[5!]Nullification Sphere *(1 workspace)
[6] Tactical Comm/Sensor (Array Level 10)
[core] Control Room (C6 Infomat, Comm/Sensor 8, 10 control stations, 1 workspace)

Central Hull
[1] Advanced Metal Laminate Armor (dDR 10)
[2!] Weapon – Secondary Battery (10 300 MJ Atomic Guns, turreted)
[3] Cargo Hold (1500 tons)
[4!] Machine Shop ($500K/hr, 10 workspaces)**
[5-6] Hangar Bay (600 tons, launch 100 tons/minute)

Rear Hull
[1] Advanced Metal Laminate Armor (dDR 10)
[2] Weapon – Medium Battery (3 1 GJ Atomic Guns, turreted)
[3-4] Tesla Coil Power Plants (provide 5 Power Points ea.)
[5-6!] Electron Drive (each providing 5G acceleration, max speed .0005c
[core!] Nega Barrier (Heavy Screen; dDR 150/300; adjustable; 1 workspace)

Features:
Streamlined, wings, gravitic vector, carries 20 lifeboats

*Works like Defensive ECM, but is a high energy system. With a successful Electronics (Nullification Sphere) roll, double the to hit penalty.

**Works like a Fabricator, but due to lack of computer automation in this setting, requires more human crew to operate.

PILOTING/TL 6+3 (HIGH-PERFORMANCE SPACECRAFT)
dST/HP 150; Hnd/SR -1/5; HT 13; Move 10G/.001c; LWt. 10,000; Load 1110; SM +10; Occ 50+50 ASV; dDR 20; Cost $2.792B

EDIT: Incorporated some nifty suggestions inspired by sir-talen and Shrale.

Re: [Spaceships] of the Solar Patrol
 

I'd argue against the fabricator. Automated CAD/CAM systems don't fit the idea of a world without printed circuits. They'd more likely have a workshop with tools a human would use manually.

Re: [Spaceships] of the Solar Patrol
 

The description is pretty brief, but as near as I can tell it is not fully automated (that would be the Robofac). However, it might make more sense for the flavor of the setting to just increase the number of people required to run the thing - 10 sounds like a good number to me.