Spaceships: Escape to the asteroids

[Fred Brackin]

Originally Posted by Ulzgoroth

How do you accidentally compress a fuel tank?

It's a colony ship, not a flying colony. It's presumably not intended for indefinite habitation, though I don't know how long the mission schedule is.

Also, unless I'm confused about the PF system, there's really nothing you can do to negate cosmic rays. With an insanely thick hull you might divide them by, say, 10.

The fuel not the tank, though denting the side of a full tank might do the job. NSW fuel is supposed to be just short of critical so you can make it go critical when you try and "burn" it.

A "colony" ship without a colony waiting for it at journey's end needs am very substantial industrial capacity and long tern habitability for the period of time the habitat is beign built. 20 people probably aren't enough for that job anyway..

.....and yes, you can shield agianst cosmic rays. It just takes a substantial amount of mass. Designs for L5 colonies take this into account. It's actually a substantial ortion of their mass budget. you can't do it in thin hulled ships though.

Please trust me on this. We went all through this at great length and in great detail during the Transhuman Space playtests.

[Ulzgoroth]

Originally Posted by Fred Brackin

The fuel not the tank, though denting the side of a full tank might do the job. NSW fuel is supposed to be just short of critical so you can make it go critical when you try and "burn" it.

So, Spaceships does not have a 'randomly, you manage to compress your fuel and blow up' rule. It does have rules for NSW rockets, however. This being a Spaceships thread, I tend to pay attention to that text.

Originally Posted by Fred Brackin

A "colony" ship without a colony waiting for it at journey's end needs am very substantial industrial capacity and long tern habitability for the period of time the habitat is beign built. 20 people probably aren't enough for that job anyway..

There does seem to be a shortage of construction capacity on the boat, I agree. Also I suspect they'd want to carry at least one decent-sized power plant, and they don't seem to have any aboard.

Originally Posted by Fred Brackin

.....and yes, you can shield agianst cosmic rays. It just takes a substantial amount of mass. Designs for L5 colonies take this into account. It's actually a substantial ortion of their mass budget. you can't do it in thin hulled ships though.

Please trust me on this. We went all through this at great length and in great detail during the Transhuman Space playtests.

No, I think unless you want to point me to the rules you're using, I'll keep using the ones I actually have.

[Haseri]

Spaceships 5 and 8 have rules on radiation protection.

[DataPacRat]

Originally Posted by Fred Brackin

Go to the TL9 Fusion Pulse or Advanced Fusion Pulse. Those give you Delta-v of 5mps or 20 mps comapred to te 2.5 of NSW.

I'm fiddling with an alternate engine design from the boardgame source - a n-6Li Micro-fission thruster boosted with an antimatter bottle. It may be somewhat breaking the rules of reality, though, as that gives it an Isp of around 48000 sec, and an exhaust velocity of 480 km/sec.

Originally Posted by Fred Brackin

A "colony" ship without a colony waiting for it at journey's end needs am very substantial industrial capacity and long tern habitability for the period of time the habitat is beign built. 20 people probably aren't enough for that job anyway..

Part of the Main Cargo includes industrial capacity, including a power generator; and part of the Second Cargo includes additional colonists, taking the trip in coldsleep to save on life-support requirements.

[apoc527]

Forgive my ignorance, but which book has rules for partial space systems? How do I get a half size habitat? Is that all in Spaceships 8?

[Ulzgoroth]

Originally Posted by apoc527

Forgive my ignorance, but which book has rules for partial space systems? How do I get a half size habitat? Is that all in Spaceships 8?

SS7 for RAW.

[wellspring]

Originally Posted by DataPacRat

I'm fiddling with an alternate engine design from the boardgame source - a n-6Li Micro-fission thruster boosted with an antimatter bottle. It may be somewhat breaking the rules of reality, though, as that gives it an Isp of around 48000 sec, and an exhaust velocity of 480 km/sec.

Might I suggest the Fusion Rocket? It's a straightforward TL9 design, and unlike NSW, antimatter and pulse drives you can manufacture more fuel once you arrive and found your colony. As Fred points out, on long missions like this, delta-V is far more important than thrust in terms of cutting trip time.

Originally Posted by DataPacRat

Part of the Main Cargo includes industrial capacity, including a power generator; and part of the Second Cargo includes additional colonists, taking the trip in coldsleep to save on life-support requirements.

Coldsleep passengers should be placed in habitat sections (there are rules for how tightly you can pack them and their hibernation pods). I'm assuming this isn't THS-style nanostasis and they need some greatly reduced life support?

Industrial capacity and a power generator should be designed into the ship. If necessary, make them size 7 to fit them all together. There are several good reasons (game mechanic reasons and practical reasons) to do this, but if nothing else, if you're going to carry all that stuff, why not also be able to use it? I mean, while you're in transit. Plus, you need that stuff to build your base to be able to operate before you, you know, actually build the base. If the power plant and factory are each full-sized, you get a +1 to your ship's HT.

Support ships and shuttles should be in a hangar section, which includes launch/recovery equipment, parts and tools for maintenance, workspaces to specify the crew requirement and a bay door to launch the shuttles through.

As a GM, I'd rule that factories, reactors, and shuttles that are carried as cargo can't be operated. They're mothballed and crated, possibly in pre-assembled parts. You're not saving mass carrying them but not using them, and both fission and fusion reactors will operate for decades before you need to refuel them. If the plot demands it, then go ahead, but a pre-planned colony would never do it this way, and even a jury-rigged ship would probably be re-fitted in flight by the crew to get those components on line and ready to use upon arrival.

Armor isn't efficient for radiation protection if that's its only intended purpose. With a couple exceptions, ANY ship's system can be used as radiation protection. Make sure at least one of your habitat sections can accommodate the entire crew crowding in as a "sweatbox" for solar storms, then put that section in the core space of your best-protected area. Spaceships 8 has rules for this that are pretty straightforward (plus rules for hibernating crew). With that said, a 1/3 size armor module in each section of the ship is just plain common sense to deal with impacts.

A single midships turreted weapons mount would be a good idea; once you install the system, drop all the weapons except one and you have something that is mostly a cargo module. Only now you have an active defense against micrometeors. It might also come in handy for drilling. Power it with that reactor you took out of storage. Size the weapons module to match your power plant's SM.

One area where you aren't skimping but probably can is your control room. Undersizing your control room hurts handling and maneuverability, but the ship is intended for one extremely low-thrust mission, followed by docking in microgravity. A better pilot or AI weighs a lot less than having a combat ship's load of attitude thrusters. That saves you 2/3 of a space, which you can use for something else.

What are the specialized rooms? Workshops for at least three skills, and a medbay? You'll want to specify that. I'd also recommend either very good VR or a very nice rec room. Even once they arrive on the asteroid it's going to be a very grim life.

Also, you'll want to at least roughly stat out the shuttles and mining ships and etc. A refinery of some kind will be essential, not just to electrolyze water, but to synthesize fertilizers, produce industrial chemicals, lubricants, coolants, convents, solvents, etc. If such a "flex-refinery" isn't available in your setting or TL, then a larger chem lab space is required.

[DataPacRat]

Originally Posted by wellspring

Might I suggest the Fusion Rocket? It's a straightforward TL9 design, and unlike NSW, antimatter and pulse drives you can manufacture more fuel once you arrive and found your colony. As Fred points out, on long missions like this, delta-V is far more important than thrust in terms of cutting trip time.

Looking back and forth from the source material to Spaceships, it's plausible that the n-6Li Micro-fission thruster can be described as what Spaceships calls a Fusion pulse drive, and adding the AM bottle makes it the advanced fusion pulse drive.

Coldsleep passengers should be placed in habitat sections (there are rules for how tightly you can pack them and their hibernation pods). I'm assuming this isn't THS-style nanostasis and they need some greatly reduced life support?

Standard GURPS coldsleep, with 1/10th life-support requirements.

Industrial capacity and a power generator should be designed into the ship. If necessary, make them size 7 to fit them all together. There are several good reasons (game mechanic reasons and practical reasons) to do this, but if nothing else, if you're going to carry all that stuff, why not also be able to use it? I mean, while you're in transit. Plus, you need that stuff to build your base to be able to operate before you, you know, actually build the base. If the power plant and factory are each full-sized, you get a +1 to your ship's HT.

Support ships and shuttles should be in a hangar section, which includes launch/recovery equipment, parts and tools for maintenance, workspaces to specify the crew requirement and a bay door to launch the shuttles through.

As a GM, I'd rule that factories, reactors, and shuttles that are carried as cargo can't be operated. They're mothballed and crated, possibly in pre-assembled parts. You're not saving mass carrying them but not using them, and both fission and fusion reactors will operate for decades before you need to refuel them. If the plot demands it, then go ahead, but a pre-planned colony would never do it this way, and even a jury-rigged ship would probably be re-fitted in flight by the crew to get those components on line and ready to use upon arrival.

I could swap out four of the cargo holds with more explicit Hanger, Factory, Mining, and Refinery modules. A fifth one could be the reactor; the source text has the power plant being a Farnsworth-Bussard fusor; Spaceships says that at TL9 fusion reactors can only be on SM+10 or larger ships, but I'm probably going to ignore that.

Armor isn't efficient for radiation protection if that's its only intended purpose. With a couple exceptions, ANY ship's system can be used as radiation protection. Make sure at least one of your habitat sections can accommodate the entire crew crowding in as a "sweatbox" for solar storms, then put that section in the core space of your best-protected area. Spaceships 8 has rules for this that are pretty straightforward (plus rules for hibernating crew). With that said, a 1/3 size armor module in each section of the ship is just plain common sense to deal with impacts.

3 1/3 armor modules it is, then; and I've already got notes on the solar storm shelter.

A single midships turreted weapons mount would be a good idea; once you install the system, drop all the weapons except one and you have something that is mostly a cargo module. Only now you have an active defense against micrometeors. It might also come in handy for drilling. Power it with that reactor you took out of storage. Size the weapons module to match your power plant's SM.

Part of the industrial cargo is a wakefield electron accelerator, whose beam is useful as a borer for mining, an electrothermal rocket, carving material during fabrication, and as a laser initator - and as a weapon. Building it as a Weapon/laser in Spaceships is probably close enough.

One area where you aren't skimping but probably can is your control room. Undersizing your control room hurts handling and maneuverability, but the ship is intended for one extremely low-thrust mission, followed by docking in microgravity. A better pilot or AI weighs a lot less than having a combat ship's load of attitude thrusters. That saves you 2/3 of a space, which you can use for something else.

Noted.

What are the specialized rooms? Workshops for at least three skills, and a medbay? You'll want to specify that. I'd also recommend either very good VR or a very nice rec room. Even once they arrive on the asteroid it's going to be a very grim life.

The setting does already include extensive VR (and AR), including full-sensory simulations.

Also, you'll want to at least roughly stat out the shuttles and mining ships and etc. A refinery of some kind will be essential, not just to electrolyze water, but to synthesize fertilizers, produce industrial chemicals, lubricants, coolants, convents, solvents, etc. If such a "flex-refinery" isn't available in your setting or TL, then a larger chem lab space is required.

Given how much the design of the main ship has changed, I think I'll try to get it settled down before I worry much about smaller craft. :)


This has all been very good feedback, and I thank everyone who's commented so far.

At the moment, the revised draft design looks something like this:

TL9, Exposed Radiators
SM+8, unstreamlined: 1000 tons

1 3*1/3 Armor, Steel: $.18M
5 Cargo holds: 250 tons capacity
1/3 Small Control room: $.6M
1 Engine room: $.3M
1 Factory: Fabricator: $50M
1 Fuel tanks: $.3M
Fuel, 50 tons nuclear fuel pellets: $2.5M
2 Habitat: 24 bunks, total life support: $1M
1 Habitat: 1 Sickbay with automed, 5 workshops: $1.1M
1 Habitat: 24 Hibernation chambers: $1M
2/3: Habitat: 16 Hibernation chambers: $.66M
1 Hanger: $.1M
1 Mining: $1M
1 Refinery: $1M
1 Power Plant, Fusion: $10M
1 Reaction Engine, Advanced Fusion Pulse: $20M
1 Weapon turret, Medium, 1 laser beam (and 30 tons cargo): $2M
Spin Gravity: $.1M

Total cost for 1-way trip: $90.85M (plus cost of misc colonization gear)
Delta-vee: 20 mps


I'm currently toying with swapping spaces of cargo for more hibernation pods or more fuel - though 32 km/sec is several times what's needed to get to the asteroid belt.

[Fred Brackin]

Originally Posted by Haseri

Spaceships 5 and 8 have rules on radiation protection.

Yes. Spaceships 5 p.40 and Spaceships 8 p.8.

These rules greatly favor larger ships. Cosmic rays do divide PF by 100 so you want a larger ship with at least 1 armor system all around.

Mostly though I'd want the TL10 gene package or the TL11 nano before I tried to colonize deep space. It's not a friendly environment.

[DataPacRat]

Originally Posted by Fred Brackin

Yes. Spaceships 5 p.40 and Spaceships 8 p.8.

These rules greatly favor larger ships. Cosmic rays do divide PF by 100 so you want a larger ship with at least 1 armor system all around.

Mostly though I'd want the TL10 gene package or the TL11 nano before I tried to colonize deep space. It's not a friendly environment.

The source material I'm using mentions a few radiation protection systems for each 8-man crew unit: "A charged plasma sustains a high electrical potential (10 Gev) about the hab unit for protection against most galactic cosmic rays. When a charged particle intercepts this magnetic field, its path curves to avoid the occupants. If a solar storm erupts, the crew must evacuate into a small (8-meter dia) storm shelter. The shelter is shielded by 100 kg/m^2 of polyethylene (12 cm thick), plus water propellant and graphite."

I know that one of the 3e GURPS Vehicles extensions mentioned magnetic shielding, but I don't recall noticing anything of the sort in 4e's Spaceships system.