Re: GURPS Spaceships, in use!
 

I just got a copy last night, and I decided to try to make Serenity, too. My first step was to check out wikipedia's entry so I'd have a target mass/size. I also read the various techy bits in the Serenity RPG so I'd get the technology right.

I must politely disagree with your write-up: mass is ~1200 tons and length is appropriate for streamlined SM+8, main power plant is stated to be a superscience fusion not fission, all long-term vessels have total life support (although quality is so poor that people buy extra food), and the main cargo bay is not a hangar since it can't function as an airlock.

Here's my version. I do like your idea of the rotary reactionless engine, instead of the standard reactionless. I thought about a de-rated fusion reactor, and I'm still vacillating on it.

Firefly Mid-Bulk Transport (TL10^)
SM+8 Streamlined 1000 tons Length 270 feet dST/HP 70 HT 13
dDR 7 Occ 5+4 Load 261 tons Cost $41.9M + $0.2M

Space: Move 0.5G/c Hnd/SR -1/5
Air: Move 10/1250 Speed 2500 mph Hnd/SR +1/5

Artificial Gravity ($1M)
4 Airlocks (3 locks, 2 each 2 person, 1 of 4 person)

Front
[1] Metallic Laminate Armor, dDR 7 ($1M)
[2] Control Room, C8, Lvl 7, 4 stations ($2M)
[3] Hangar Bay, 30 tons capacity, 20 tons launch rate, ($100k)
[4] Hangar Bay, 30 tons capacity, 20 tons launch rate, ($100k)
[5] Habitat, Total Life Support, intended for crew, 1 luxury cabin, 1 cabin ($1M)
[6] Habitat, Total Life Support, intended for crew, 3 cabins ($1M)

Center
[1] Metallic Laminate Armor, dDR 7 ($1M)
[2] External Clamp ($100k)
[3] Cargo Hold, 50 tons
[4] Cargo Hold, 50 tons
[5] Cargo Hold, 50 tons
[6] Habitat, Total Life Support, intended for passengers, 3 cabins ($1M)
[c] Habitat, Total Life Support, intended for passengers, 1 cabin, 2 bed sickbay ($1M)

Rear
[1] Metallic Laminate Armor, dDR 7 ($1M)
[2!] Contragrav Lifter ($10M)
[3] Engine Room, 1 Wksp, ($300k)
[4] Fuel Tank, 50 tons ($300k) + Jet Fuel ($200k)
[5] Jet Engine, 1G accel, 1 fuel tank per hour ($10M)
[6!] Standard Reactionless Engine, 0.5G accel ($1M)
[c] Fusion Reactor, 2 PP, 200 years ($10M)

Notes: The two hangar bays are specifically designed for the 30 ton shuttles (below). This version is the medical evacuation variant.

Firefly Shuttles (TL10^)
SM+5 Streamlined 30 tons Length 50 feet dST/HP 20 HT 13
dDR 1 Occ 1+8 SV Load 10 tons Cost

Space: Move 0.5 G/c Hnd/SR 0/4
Air: Move 10/1250 Speed 2500 mph Hnd/SR +5/5

Winged ($150k)
Artificial Gravity ($30k)
1 Airlock (1 lock, 1 person)

Front
[1] Light Alloy Armor, dDR 1 ($15k)
[2] Control Room, C6, Lvl 4, 1 station ($60K)
[3] Passenger Seating, 2 seats ($10k)
[4] Passenger Seating, 2 seats ($10k)
[5] Passenger Seating, 2 seats ($10k)
[6] Passenger Seating, 2 seats ($10k)

Center
[1] Light Alloy Armor, dDR 1 ($15k)
[2] External Clamp ($3k)
[3] Cargo Hold, 1.5 tons
[4] Cargo Hold, 1.5 tons
[5] Cargo Hold, 1.5 tons
[6] Fuel Tank, 1.5 tons ($10k) + H/O Fuel ($1.2k), lasts 4 days for Fuel Cell
[c] Fuel Cell Power Plant, 1 PP, lasts 24 hrs on internal ($15k)

Rear
[1] Light Alloy Armor, dDR 1 ($15k)
[2!] Contragrav Lifter ($300k)
[3] Engine Room, 1 Wksp, ($15k)
[4] Fuel Tank, 1.5 tons ($10k) + Jet Fuel ($6k)
[5] Fuel Tank, 1.5 tons ($10k) + Jet Fuel ($6k)
[6] Jet Engine, 1G Accel, 1 fuel tank per hour ($300k)
[c!] Standard Reactionless Engine, 0.5G accel ($30k)

Notes: Originally, these shuttles were used for short-term cargo and crew transport, and so had a mix of seating and cargo space. Maximum endurance on its own would be 5 days without the need to re-electrolyze stored water into fuel. Jet Fuel stores are limited (2 hours duration at maximum), but for most planetside travel the reactionless engine would be used.
Sometimes the 4 Passenger Seat systems are removed and turned into a single cabin. In Firefly/Serenity, Inara's shuttle was altered this way.

Re: GURPS Spaceships, in use!
 

I like both Firefly designs so far. I made one as well, and am pleasantly surprised there are two others here already.

My design differs because my approach was to follow the design of the ship more literally in terms of where the systems were placed By looking at the design and dividing it in three, you can see it corresponds to the head, thorax, and abdomen of an insect. I broke at least one rule from GURPS Spaceships, which says engines can only be rear-hull mounted. The Firefly clearly has engines attached to struts in the middle section. Maybe all this doesn't stricty make a difference in terms of the rules, but hey, it's too late now. :\

I was using the blueprints (created by the designers of the ship for both TV and the movie) available at QMx for reference. According to them, the shuttles are 20 tons, its cargo capacity is 80 tons, and its loaded mass is closer to only 300 tons (585,000 lbs)! Despite this, due to its size and the need for larger systems, I went with SM8 (1000 tons).

I did away with the Contragravity Lifter and instead elected to use a Gravitic Compensator, mostly due to lack of space. The engines and streamlining seem to be enough -- no need for Contragravity.

Note the Shielded Cargo Space (representing those nooks and crannies for hiding illegal cargo).

The Firefly drive is a fudge, based on their ability to travel between planets in a matter of days. Some of the Habitat costs are fudged as well, as they are odd configurations.

===

FIREFLY CLASS TRANSPORT (TL9^)
SM +8 streamlined hull
(loaded mass ~1000 tons, length 89 yds)
Cargo ~100 tons

Piloting/TL9 (Aerospace, High-performance Spacecraft)

Front Hull
[1] Control Room (Cockpit) TL9 (complexity 9, comm/sensor 6, 2 stations) [1.9M]
[2] Habitat (4 cabins) TL9 [600K]
[3] Fuel Tank TL7 50 tons [300K]
[4] External Clamp TL7 [100K]
[5] Armor (Light Alloy) TL7 dDR5 [500K]
[6] Solar Panel Array (1 Power Point) [5M]

Center Hull
[1] Reaction Engine, Nuclear Thermal Ram Rocket: High Thrust TL9 [5M]
[2] Hangar Bay (20-ton shuttle) plus 2 escape pods TL9 [100K]
[3] Hangar Bay (20-ton shuttle) plus 2 escape pods TL9 [100K]
[4] Cargo Hold (50 tons)
[5] Cargo Hold (50 tons) plus EV Mule [100K]
[6] Reaction Engine, Nuclear Thermal Ram Rocket: High Thrust TL9 [5M]
[c] Habitat (galley) TL9 [300K]

Rear Hull
[1!] Reactionless Engine TL^ (Pseudo-Velocity Firefly Drive) [10M]
[2] Habitat (4 bunkrooms) TL9 [600K]
[3] Engine Room (stations: 1) TL9 [300K]
[4] Fuel Tank TL7 50 tons [300K]
[5] Habitat (sickbay, 2 beds) TL9 [300K]
[6] Armor (Light Alloy) TL7 dDR5 [500K]
[c] Power Plant, Fission Reactor TL8 (1 Power Point) [3M]
Reaction Engines (High Thrust): delta-V 0.45 mps; 2G acceleration
Reactionless Engine (Firefly Drive): 200G / Full Burn 500G (uses fuel)
Air speed: 3,500 mph (Acceleration 20, Top speed 1750 y/s; Hnd -1, SR 5)

Design Features:
Artificial Gravity [1M]
Gravitic Compensator [1M]
Airlocks (3 EVA Hatches, 1 Cargo Door Airlock)
Auxiliary Power System, Landing Gear, Routine Equipment
Shielded Cargo Space (1.5 tons) [12K]
2 Shuttles (643K ea.) [1,286K]

Total Cost: 37.3M

===

STANDARD FIREFLY SHUTTLE
SM +5 streamlined hull
(loaded mass 20 tons, length 15 yds)
Cargo 15 tons

Piloting/TL9 (Aerospace, High-performance Spacecraft)

Front Hull
[1] Fuel Tank TL7 1.5 tons [10K]
[2] Cargo (1.5 tons)
[3] Cargo (1.5 tons)
[4] Cargo (1.5 tons)
[5] External Clamp TL7 [3K]
[6] Armor (Light Alloy) TL7 dDR1 [15K]
[c] Control Room (Cockpit) TL9 (complexity 7, comm/sensor 3, stations: 1 [60K]

Center Hull
[1] Passenger Seating TL7 (2) [10K]
[2] Passenger Seating TL7 (2) [10K]
[3] Cargo (1.5 tons)
[4] Cargo (1.5 tons)
[5] Cargo (1.5 tons)
[6] Armor (Light Alloy) TL7 dDR1 [15K]
[c] Engine Room TL9 [15K]

Rear Hull
[1] Reaction Engine, Nuclear Thermal Rocket TL9 [300K]
[2] Cargo (1.5 tons)
[3] Cargo (1.5 tons)
[4] Cargo (1.5 tons)
[5] Cargo (1.5 tons)
[6] Armor (Light Alloy) TL7 dDR1 [15K]
[c] Fuel Tank TL7 1.5 tons [10K]
Reaction Engines: delta-V 0.9 mps; 0.1G acceleration
Air speed: 800 mph (Acceleration 1, Top speed 400 y/s; Hnd 3, SR 5)

Design Features:
Winged [150K]
Artificial Gravity and Gravitic Compensator [30K]
Airlock (1), Auxiliary Power System, Landing Gear, Routine Equipment

Total Cost: 643K

Re: GURPS Spaceships, in use!
 

If you really want to blow budgets, go into antimatter fuel!

Re: GURPS Spaceships, in use!
 

I guess, as the designer of the system, you'd also get some kickbacks of that fictional money. ;-)

Re: GURPS Spaceships, in use!
 

So, I've got a directed question for any of you:

Without superscience, how do you get a colony ship to Alpha Centauri (requires about 4000 mps delta-V)?

At TL9, it seems impossible - even using a magsail for braking (to save half the delta-V requirement), multi-staging like crazy, an Adv Fusion Pulse Drive, and the Delta-V Increase table on page 27, that still gives only 32 mps per stage... which comes to 63 stages.

At TL10, it comes just into possibility - using the same parameters, you get 160 mps per stage, or 13 stages. If the colony ship (final stage with magsail) is SM+10, the whole vessel would be SM+23 when it leaves the solar system. And let's not even mention the cost...

At TL11, it becomes possible to do - same parameters again, leaves us with only four extra stages necessary. When it leaves the solar system, the colony ship (SM+11) with all its boosters is going to be SM+15 or larger.

Antimatter has higher delta-V, but generally the fuel costs so much more than the efficiency increase, that it isn't worth it. The exception might be Antimatter Pion (3400 mps per fuel tank), which means that the colony ship could get there in a single stage, 2 at the highest. Fuel cost is still astronomical.

So... am I missing anything?

Re: GURPS Spaceships, in use!
 

I'm still reading the book (I finally bought it), but why would it require 4000 mps delta-V? As I understand it, you only need enough dV to get out of whatever orbit you're in, to acclerate a little, then to decelerate and enter a new orbit (and if you're going slowly enough, you can use the new orbit itself to brake.) So if you're willing to take a very, very long time, there's no need for a lot of dV.

Re: GURPS Spaceships, in use!
 

Read the last part of the boxed text on page 21. The scenario is: how do you get to Alpha Centauri without superscience (which requires 4000 mps of delta-V)?

Re: GURPS Spaceships, in use!
 

Not trying to be snarky, but the only answer that works is Handwavium. It was good enough for the show...

Re: GURPS Spaceships, in use!
 

4,000 mps is to get to alpha centauri (including braking) at about 1% of light speed in 400 years with braking time. Obviously you can do so more slowly or more quickly...

Re: GURPS Spaceships, in use!
 

A lot of colony ships are in book 5. Quick and dirty to carry a minimum of 500 colonists, try a SM+13 ship set up like this:

Front Hull
[1] Diamondoid armor
[2] Habitat (500 luxury cabins, 100 minifacs, 100 establishments, 100 labs, 2,500 tons cargo.)
[3] Hangar (10,000 tons of landing craft, roll on/off cargo, probes, etc.)
[4] Magsail
[5] Open Space (farms)
[6] Fuel
[core] Control Room

Central Hull
[1] Diamondoid Armor
[2-6] Fuel
[core] Reactor

Rear Hull
[1] Diamondoid Armor
[2-5] Fuel
[6] Adv. Fusion Pulse

It therefore has 10 fuel tanks. At TL11, an advanced fusion pulse drive gets 350 mps per tank. We multiply that by 1.4 for having 10 tanks, which gives us a 490 mps per tank. 490 x 10 = 4,900 mps, and we're off with room to spare!







Suppose you assume that 12 systems of the colony ship will be fuel tanks.