GURPS Spaceships, in use!

[Mark Skarr]

Originally Posted by dirtysnowball

I would like to see the ability to make smaller craft, though. And a Transhuman Space Ship Book (Volume 1), and a pony, and...

Wait for the rules on mecha. It won't be a pony per se unless your pony is 30+ tons . . ..

(singing)
My Little Pony, Apocalypse Pony!
(stops singing due to environmental damage)

[DemiBenson]

Originally Posted by David L Pulver

Yah. I think you missed that the delta-V is per tank. E.g., if you've got advanced fusion pulse at 20 mps/tank and then use 13 tanks for a x1.6 on the delta-V increase table, the delta-V is calculated as follows:

20 mps x 13 tanks x 1.6 = 416 mps. So it's only 10 stages at that TL. Still kind of dubious, though you do better with magsail and the final stage being mostly tank. But in fact, you can do slow interstellar as a practical multi-stage at TL10 and as a single stage at TL11 (TL10 if you go antimatter plasma). And you can reach 10-12% of light as a multi-stage (Daedelus, etc.) at TL11 without too much problem.

It's not that I missed (since several others of my designs dutifully added up dV from multiple tanks), but I .... er.... missed adding up the dV per tank for these calculations.

Yeah, that makes a lot more sense now.

Off to finish my Jump Gate carrier vessel...

(Note to self: no more Spaceships while at work)

[DemiBenson]

Originally Posted by dirtysnowball

Full marks for GURPS Spaceships, for me it's the nicest balance of realism, detail (these aren't the same thing), flexibility and playability I've seen in a set of ship design rules. And it lets me build the atomicpunk space battleships that have been orbiting in the back of my brain for years now...

Yes, quite an excellent system!

Atomicpunk? Care to share some details?

I would like to see the ability to make smaller craft, though. And a Transhuman Space Ship Book (Volume 1), and a pony, and...

I do wish that smaller craft were included, but I think I understand some of the reasons why they weren't.

The design system is also simple enough that I want to try a similar set of rules for my steampunk setting.

[ham2anv]

B'rel-class Bird-of-Prey

The B'rel-class bird-of-prey is the workhorse of the Klingon fleet. Small, sturdy, and well-armed for a ship its size, the B'rel is designed to be a fast attack ship, often deployed in packs of 3-5.

The B'rel's major problem is that it is woefully underpowered. This isn't noticed while traveling under cloak, but in battle a B'rel's engineering crew will often be found struggling to shuffle energy to critical systems. The most common choice is between two of weapons, secondary impulse engines, and increased deflector performance.

Crew typically consists of a captain, a first officer, a chief engineer, a pilot, a communications and sensor officer, a tactical officer, a surgeon, two gunners, and 36 enlisted technicians.

TL: 12^
dST/HP: 200

HT: 13
Hnd/SR: -2/5
Move: 4G/c
SM: +11
LWt.: 30,000
dDR: 550/550/450
Occ: 52ASV
Load: 5,250
Cost: B$7.33

Design Features: artificial gravity, gravitic compensators

Design Switches: Force Screens are dDRx10 and Hardened 1 against missiles; Force Screens do not regenerate ablated dDR every combat round, but may be jury-rigged to restore half of lost dDR.

Front Hull

[1-2] Exotic Laminate Armor (dDR 200)
[3!] Medium Weapon Battery (2 fixed 3GJ heat beams, 1 fixed 48cm warp missile launcher)
[4] Tactical Comm/Sensor Array (Level 10)
[5!]Secondary Weapon Battery (6 fixed 1GJ heat beams, 3 fixed 40cm warp missile launchers, 1 turreted 1GJ tractor beam)
[6] Control Room (Complexity 9 computer network; 8 control stations)

Central Hull

[1-2] Exotic Laminate Armor (dDR 200)
[3] Habitat (1 luxury cabin, 6 cabins, 12 bunkrooms, 19 replicator minifacs, teleport projector, five-bed sickbay, 40-man mess hall, gym, 745 tons of steerage cargo)
[4-6] Cargo Holds (4,500 tons)
[core!] Cloaking Device

Rear Hull

[1] Exotic Laminate Armor (dDR 100)
[2-3!] Stardrive Engine (FTL-2)
[4!] Heavy Force Screen (dDR 350)
[5-6!] Hot Reactionless Engine (provides 4G acceleration)
[core] Antimatter Reactor (provides four Power Points)

[Mark Skarr]

The Masque of Pandora on her maiden flight.

The Masque of Pandora is the third ship of the Longfellow-class. Her two sister ships, the Longfellow and the Pilgrimage Beyond the Sea were launched only months ago. She is shown rigged for combat or hyperspace travel with her radiators retracted into their armored housings along the aft sides of the ship.
Her twin spinal cannons were upgraded to fire 100 kiloton warheads after the Longfellow discovered her 25 kiloton rounds were ineffective against Vex planetary shields. Her nose lasers were also upgraded to 30gj lasers for the added power though at the expense of rate of fire from the 300mj lasers on the Longfellow and Pilgrimage Beyond the Sea.

TL 9^
Ship: Longfellow-Class Heavy Cruiser.
Skill: Pilot (Low-Performance Spacecraft)
dST/HP: 500
HT: 13
Move: .2G / .02c
Hnd/SR: -4/5
LWT: 300,000
Load: 3860
SM: +13
Occ: 4,510ASV
dDR: 100
Cost: $39,732,000,000 (without fighters/transports)

Front:
[1] Armor, Advanced Metal Laminate (dDR 100)
[2-3!] 48cm Electromagnetic Primay Cannon *
[4] Control Room (Complexity 8; Comm/Sens 11)*
[5-6!] Medium Weapons Battery (2x 30GJ Laser Cannons; 1x 64cm Missile Launcher; fixed forward)*

Center:
[1] Armor, Advanced Metal Laminate (dDR 100)
[2!] Tertiary Battery (30x turreted 30mj VRF Laser Cannons)*
[3-4] Habitat*
[5] Tactical Array (Level 13)*
[6] Fusion Reactor (2 pp)*
[Core] Fusion Reactor (2 pp)*

Rear:
[1] Armor, Advanced Metal Laminate (dDR 100)
[2] Hangar (10k ton max; 1k ton launch)*
[3-4!] Rotary Reactionless Drive (.1g acc; .01 c max)*
[5!] Hyperspace Stardrive*
[6] Fusion Reactor (2 pp)*
[Core] Fusion Reactor (2 pp)*

Features:
Hardened Armor, Total Life Support

Habitat Breakdown:
10 Luxury Cabins for Command Staff; 200 Officers in Cabins; 300 Flight Crew in Cabins; 3,000 enlisted in bunks; 1,000 marines in bunks; 2x 20-bed sickbays; 10 breifing rooms; 10 minifacs; 10 offices for Command Staff; 10 Gymnasiums; Chemistry Lab; Biology Lab; 3,860 tons in Steerage.

* 30 workstations

Weapons:
Weapon; Damage; sAcc; Range; Rcl; Shots
Primary 100kt Nuclear; 8dx1,000 burn ex rad sur; -6; S; 4; 1,500
linked; 6dx2,000 cr ex
30gj Laser Cannons; 6dx10(2); 0; L; 1; -
64cm Missiles; 6dx16(2); -2; X; 1; 100
30mj VRF Laser Cannons; 6d(2); 0; S; 1; -

[Moonsword]

The Airbus is a limited superscience design intended for an early TL10 background. The only bit of superscience gear on the Airbus is its rocket, which is twice as efficient as a TL9 HEDM rocket - the world background relies on a mixture of HEDM rockets for surface-to-orbit lift and antimatter thermal rockets for interplanetary cruises. The Airbus itself mainly fills the niche of a small business jet today, so long as the spaceplane's fuel requirements could be met - outside the reach of modern (TL8) technology but possible for TL9.

This particular example is configured as a passenger hauler with a minimum of cargo space but the passenger and cargo areas are modular and can be switched around with little hassle. The second most common use is as an express low-orbital courier, with a quick boost into orbit and a rapid descent to another spaceport. In this configuration, there are two seats in the rear of the cabin for passengers while the forward passenger space and one of the rear passenger modules are replaced by cargo holds for a total of nine tons. The large fuel reserve is for either boosts from higher-gravity planets or orbital/lunar operations where the greater delta-V budget from an antimatter rocket is unnecessary.

Hull: +5 SM, streamlined, TL10
Front: Armor (light alloy, dDR 1, 15K), Cargo Hold (1.5 tons), Control Room (core, Complexity C6, comm/sensor rating 4, 1 control station, 60K), Passenger Seating x4 (8 seats, 40K)
Center: Armor (light alloy, dDR 1, 15K), Engine Room (core, 1 workspace, 15K), Fuel Tank x3 (9 tons, metallic hydrogen, 3 mps delta-V, 30K), Passenger Seating x2 (4 seats, 20K)
Rear: Fuel Tank x5 (7.5 tons, metallic hydrogen, 5 mps delta-V, 50K), HEDM Rocket (2Gs, 1 mps per fuel tank, 60K)
Design Features: Winged (150K)
Cost: 455K
Crew: 1 pilot, 1 flight engineer
Stat Block: TL10, dST/HP 20, damage threshold 2 dHP, HT 13, Hnd/SR 0/4, Move 2Gs/8 mps, SM +5, LWt 30 tons, dDR 1/1/0, Occ (Short-Term) 2 crew + 12 passengers, Load 2.7 tons, Cost 455K, Air Performance 3500 mph, Hnd/SR +4/+5

[DemiBenson]

A TL10 (with one TL^ feature) for sending a startup colony to Alpha Centauri without needing a generation ship.


Steppingstone Carrier Booster (TL10)
SM+12 100,000 tons Length 600 feet dST/HP 300 HT13
dDR 0/15/0 Occ 200 Load 65,000 tons Fuel + 30,000 tons Upper Stage Cost $2.39B + $19.5B Fuel
Move 0.005G/2080 mps Hnd/SR -6/5

Front
[1-6] Upper Stage, Steppingstone Carrier (below)

Center
[1-6c] Fuel Tank, holds 35,000 tons ($210M) + Fuel Pellets ($10.5B)

Rear
[1-6] Fuel Tank, holds 30,000 tons ($180M) + Fuel Pellets ($9B)
[c] Advanced Fusion Pulse Drive, 0.005G accel, 100 mps per tank, 10 workspaces ($2B)

Notes: 13 Fuel Tanks gives delta-V x1.6, for a total of 2080 mps.

For a one-way voyage to Alpha Centauri
Time to Accelerate: 18928 hrs (2.16 yrs)
Distance Traveled during Boost: 752 AU
Cruise Time: None. Booster is dropped and Carrier uses Ramscoop to continue

***

Steppingstone Station Carrier (TL10)
SM+11 30,000 tons Length 450 feet dST/HP 200 HT13
dDR 0/15/0 Occ 200 Load 19,300 tons Cost $3,342M + $18M (Fuel)
Move 0.01G/216 mps Hnd/SR -4/5

Spin Gravity, 0.3G max, only center section spins ($1M)

Front
[1-6] Cargo Hold, 10,000 tons, contains Steppingstone Station (below)
[c.] Ramscoop, 3 workspaces ($3B)

Center
[1] Steel Armor, dDR 15 ($6M)
[2P] Fission Reactor, 1 PP, lasts 75 years, 3 workspaces ($100M)
[3] Control Room, computer C9, sensor 10, 15 stations, 3 workspaces ($60M)
[4] Habitat, 200 cabins base, 3 workspaces ($30M)
20 establishments, 200 hibernation chambers, 5 labs including Physics ($14M),
10 MiniRobofacs $1k/hr skill-13 ($10M), 10 offices, 10 bed clinic, 10 automeds ($1M),
300 tons cargo
[5-6] Habitat, Total Life Support, 200 cabins base, 6 workspaces ($60M)

Rear
[1-6] Fuel Tank, holds 9,000 tons ($60M) + Hydrogen Fuel ($18M)
[c] High Thrust Fusion Engine, 0.01G accel, 30 mps each tank, 3 workspaces ($300M)

Notes: The main Cargo Hold is designed as a break-away container for a single vessel - when the Carrier arrives at its destination, the hold's panels are ejected and the Steppingstone Station is released to mag-brake itself into position.
6 Fuel Tanks provide delta-V x1.2, for a total of 216 mps. The Fuel Tanks are used for terminal maneuvering and any braking that cannot be accomplished via the Ramscoop.

For a one-way voyage to Alpha Centauri
Ramscoop Performance:
Remaining Distance to Alpha Centauri: 276848 AU
Travel Time: 357791 hrs (40.8 yrs)
Max Vc: 0.431c (80180 mps)

Total Travel Time: ~43 years, 40 yrs of which is at significant fractions of lightspeed.

***

Steppingstone Jump Gate Station (TL10^)
SM+10 10,000 tons Length 300 feet dST/HP 150 HT 14
dDR 50 Occ 120 Load 1,112 tons Cost $3.0412 B
Move 0.001G/375 mps Hnd/SR -5/5

6 Airlocks (each 4 person)
Spin Gravity, 0.2G max, only rear section spins ($300k)

Front
[1] Nanocomposite Armor, dDR 50 ($50M)
[2] Science Array, sensor 11, 1 workspace ($20M)
[3.] Magnetic Sail, 1 workspace ($100M)
[4-6!!!] Jump Gate, 1000 tons, 3 workspaces ($1500M)

Center
[1] Nanocomposite Armor, dDR 50 ($50M)
[2] Hangar Bay, 300 tons capacity, 100 tons per minute, 1 workspaces ($1M)
[3] Cargo Hold, 500 tons
[4!] Fabricator Factory, $100k/hr, 1 workspace ($1B)
[5!] Mining Processor, 50 tons/hr, 1 workspace ($10M)
[6PP] Fusion Power Plant, 2 PP, lasts 200 years, 1 workspaces ($100M)
[cPP] Fusion Power Plant, 2 PP, lasts 200 years, 1 workspaces ($100M)

Rear
[1] Nanocomposite Armor, dDR 50 ($50M)
[2-3] Habitat, 120 cabins base, 2 workspace ($20M)
[4] Open Space, 5 areas, devoted to farmland, 1 workspace ($100k)
[5] Open Space, 5 areas, 1 workspace ($100k)
[6] Control Room, computer C9, sensor 9, 10 stations, 1 workspace ($20M)
[c] Hangar Bay, 300 tons capacity, 100 tons per minute, 1 workspace ($1M)

Crew: 16 techs, 10 bridge => 26 crew on each of 3 shifts => 78 regular crew

Notes: This station is designed to be the minimum necessary to establish an industrialized colony. Primarily, this will be immediately setting up the Jump Gate back to Earth so specialized vessels can arrive.
However, the designers considered the possibility that no support vessel would arrive from Earth. Therefore, the Steppingstone Station has just enough refining and factory capacity to create its own support ships, although at a shockingly slow pace. In this scenario, the Carrier vessel would certainly be cannibalized for parts to speed up the process.

[Moonsword]

How is it supposed to slow down? When the ship has to reverse thrust, the ramscoop is going to be pointed aft and therefore not much use for pulling in reaction mass, if I understand the physics correctly.

Also, a 43 year flight time is getting up to the point where you probably want to consider transhuman solutions for crew - robots, AIs, mind emulations, or simply humans genemodded for an extended lifespan.

I like the design, though, aside from those caveats above (one of which is more of a setting concern than a design caveat anyway).

[joelbf]

Originally Posted by Moonsword

How is it supposed to slow down? When the ship has to reverse thrust, the ramscoop is going to be pointed aft and therefore not much use for pulling in reaction mass, if I understand the physics correctly.

Ramscoops can double up as magsails. It's in the designer's notes available to pyramid subscribers.

[Moonsword]

Thanks for the reference, I haven't checked Pyramid since about the time Martial Arts came out. That small upper stage rule looks especially useful.

And if you're already above those speeds, how do you decelerate? .4 c is about 120k km/s - 120,000,000 mps in terms of delta-V. That's well above the 1.8 km/s needed to activate the ramscoop. I think the simplest solution is to hand-wave it - say that the ramscoop's magnetic field can be 'bent' to permit it to pull in mass ahead of/beside the ship when in deceleration.