[GURPS Spaceships] TL9 SM+15 Space Habitat
 

This is an attempt to make a huge space habitat. The shape should be some kind of elongated cylinder, so I figure 60% of the SM's default length would be good. That's 420 yards in length, or about 375 meters. Since I don't know what the volume is, I can't calculate the diameter, but obviously it would be in the order of magnitude of some hundreds of meters.


Size: SM+15
Hull type: Un-streamlined, long cylinder
TL: 9

Front

[1] Factory. The station has to be able to produce stuff for the needs of the inhabitants. Since they mostly have what they need already, the factory usually runs at 10% capacity. Can make stuff worth 150 million dollars per hour at full capacity, 300 workspaces, cost 150G$ (is this a typo? It's very expensive).

[2] Normal cargo space, to store the raw materials needed for the Factory, or the unprocessed materials needed by the "mining" unit. No cost. I'll arbitrarity assign 6 workspace, for people to keep track of supplies, but the actual moving of stuff out of the cargo space is done by factory workers or mining workers. No cost, but 6 workspaces. 150k tonnes capacity.

[3] Split module:
2/3 Mining Materials Processing, to process imported minerals (usually mined from asteroids and sold to the habitat), 10k tonnes per hour of mineral processing capacity (can fill the cargo space in 15 hours, but is normally run at low capacity, e.g. 10%).
1/3 Fuel Refining, to produce fuel for auxillary craft (in the Hangar Bay module), can process 15k tonnes of fuel per hour if running at full capacity (but usually it runs at much less).
Total cost 3G$, 300 workspaces.

[4] Hangar Bay, 100k tonnes capacity, launch rate 5000 tonnes per minute (takes 20 minutes to launch or dock full capacity), 300 workspaces, 300M$

The design complement for this type of habitat is two large SM+10 ships (20k tonnes), 60 medium-sized SM+8 ships (60k tonnes) and 200 small SM+6 ships (20k tonnes). Most ships will be for transport of cargo (the two large ones, and roughly 3/4 of the medium ones and 1/4 of the small ones) or passengers. The cost of auxillary craft is not included in the cost of this habitat.

[5] Fuel tank, to store reaction mass for the Hangar Bay's ships, or the unprocessed fuel raw materials (hydrogen, probably). 150k tonnes capacity, cost 1$B. Un-manned, since the Hangar Bay crew takes care of refuelling the smallcraft, and the refinery crew handles pumping material from here and to the refinery.

[6] Weapons, tertiary battery (normally 30 weapons), 3 actual weapons, with the remaining 90% devoted to refridgerated cargo storage.
Weapons: 3 lasers with the VRF option (since they are intended to be used for meteorite defence only). Cost 1.5G$, 30 workspaces.
Cargo space, refridgerated: 135k tonnes, cost 68M$. The PDF assigns no workspaces to refridgerated cargo space, but since this is such a large facility, I'll arbitrarily assign 30 for maintenance.

Mid
[c] Control Room. Since the habitat has no proper engines, the Control Room's very low-powered thrusters must be used to shift orbit, which happens very, very slowly (the captain may need to plan decades ahead). Also, most of the computing powers fill the needs of the station's inhabitants, and most of the Control Room's control stations are manned by people who supervise the internal functioning of the space station, including senior law enforcement and administrators (the regular cops and administrators have habitat offices of their own). Computer complexity 9, comm/sensor grade 13 (TL+4), 60 control stations, 300 workspaces, cost 6G$.
edit: Like the core module in the Rear section, this module, the Control Room, is in zero gravity.

[1-6] 6 Habitat modules, totalling 120k "cabin units", 1800 workspaces, 18G$.

Rear
[c] Open space, devoted to zero-gravity recreation (small shag-cabins intended for 2-6 temporary ocupants, larger orgy rooms, zero-gravity ballgame areanas, zero-gravity water tanks), cost 60M$ (tripled because of the need for improved containment of the water, and various systems to remove bodily fluids and skin particles from the air), 60 workspaces (tripled; the extra workers are paramedics standing by in case of emergencies, or someone demanding an immediate STD test).

[1] Open space, devoted to food production sufficient to feed the entire habitat and even produce a little excess food which is stored in the refridgerated cargo space (mentioned above). Once the emergency store is full, any excess food is exported to other stations or even to the Lunar or Martian colonits. 300 workers, cost 20M$.

[2-4] Open space, devoted to parkland, soccer fields, fishing ponds, light forest, and so forth. 600 areas (30 acres, or 12 hectares, which is 400 by 600 meters), 900 maintenance workers (techs), cost 60M$.

[5] Overall Steel Armour, covering the entire ship with 1/3 of the SM's dDR, which gives a dDR of 23, or a DR of 230. IIRC in GURPS, DR 70 is the same as 25 mm of steel, so we're talking over 75 mm of steel here, which should give quite good protection against radiation, and even tiny meteorites. Cost 600M$.

[6] Power Plant (Fusion). Plenty of energy is needed to support the luxurous lifestyle of the late 21st century (even if a little of the power is occasionally used to power the meteorite defence system), and the 1 Power Point provided by this de-rated system provides plenty of fun (doubled endurance to 100 years). 300 workspaces, cost 30G$.

Design options:

Spin gravity. The maximum gravity, at the outer edge of the habitat, just next to the steel armour, is 1.15G but cabins and parkspace are distributed inwards so that one can choose to live and recreate in any gravity from 1.15G (mostly popular with sports types, paramilitary types and actual military or law enforcement, who want to stay in very good shape) and down to near-lunar gravity (0.20G), although with most living and recreational space clustered around Earth gravity and Martian gravity. Cost 300M$, no maintenance crew needed (people's conflicting desires for living quarters in specific gravity bands are handled by the Control Room).

"Cabin unit" breakdown (120k cabin units total):

1200 bed hospital (1200), gives a +4 bonus to relevant medical skill rolls (as per "Hospital Bonus", p18, and assuming that TL9 divided by 2 is rounded down)

350 large establishments (7000, x5 normal size), each accomodates 100 patrons, for a total of 35k patrons (a few of these are combined into super-sized establishments).

3500 establishments (7000), each accomodates 10 patrons, for a total of 35k patrons (a few of these are probably combined into double- or triple-sized establishments).

700 office law enforcement unit (700).

300 office administrative unit (300).

25k double-size luxury cabins (100k), half expected to contain 1 person, the other half 2 persons (some of these are combined into larger luxury suites, or to family units to accomodate larger numbers of people who wish to share a home), for a total population of 37.5k people.

3800 unused "cabin units" (can be used for normal cabins for the crew. At 2 people per cabin, that's 7600 crew, which is more than enough, since the requirements total up to only slightly more than 4500).




Total number of workers needed to man modules: 4686
(60 to man the control room, the others to perform more or less manual work, and with habitat staff (medical, law enforcement, administration) not included (these total 700 law enforcement, 300 administrative, and sufficient nurses, med technicians, physicians and surgeons to man a 1200 bed hospital).

Total cost of habitat: 210.6 billion dollars
(Cost per inhabitant, assuming 37.5k inhabitants: 5.6 M$)
(Also note that almost 3/4 of this cost is the Factory module)

I don't have an easy way to calculate the cost of the auxrillary craft, but they total to a mass of 100k tonnes, so it would be fairly expensive if viewed in isolation, although probably near-trivial when compared to the 210 billion dollars cost of the habitat itself.


Edit: Specifying that the [core] module Control Room is in zero gravity.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

This part couldn't fit into my original post (10k character size limit, or something like that):

Some questions, oddities and thoughts:

That factory is absurdly expensive. Also, its production rate is much too fast, compared to what the inhabitants can consume. It churns out 150 million dollars per hour, which means that the inhabitants can each consume 4000 dollars worth of consumer goods per hour (almost 100k$ worth of consumer goods per day).

Even if the factory normally runs at 10% capacity (and this is likely), we're talking 400 dollars worth of consumer goods per hour per inhabitant. I think it would be safe to modify the design, and split one module three ways, for 1/3 factory, 1/3 mining and 1/3 fuel refining, and still have plenty of production capacity.

I haven't been able to calculate the cost of the auxillary craft, but the standard complement is as follows:
2 x SM+10 cargo ships. (95% cargo, 5% passenger capacity)

45 x SM+8 cargo ships (90% cargo, 10% passenger capacity)
12 x SM+8 long-trip passenger ships (80 passengers, 20% cargo capacity)
3 x SM+8 short-trip passenger ships (80 passengers, 20% cargo capacity)

50 x SM+6 cargo ships (95% cargo, 5% passenger capacity)
30 x SM+6 long-trip passenger ships (90% passengers, 10% cargo capacity)
120 x SM+6 short-trip passenger ships (90% passengers, 10% cargo capacity)
All at TL9.

I also haven't been able to calculate how much delta-V you can get out of all the stored fuel, assuming a typical TL9 drive for an SM+10, SM+8 or SM+6 transport ship.

One Open Space module devoted to Farming, 4 hectares, or 40k square meters, producing sufficient food for 37.5k people? I was sceptical at first, but having done the "math", I think it might be doable with TL9 hydroponics, since it is a little over one square meter per person. The main problem may be the crew assigned (I imagine much more than 20 techs would be needed) and the cost (I'm not sure if 20 million dollars can do it, although I'm less sceptical about this than about the manning).

More than 3 inches of armour should produce good protection against radiation, probably even cosmic rays. It can probably also handle very small meteorties, if the meteorite defence lasers should miss.

135k tonnes of stored food, divided by 37.5k inhabitants, gives 3.6 tonnes per inhabitant. That should last for a while, if something goes wrong with the hydroponics.


I'd like to have a figure for how much input, measured in mass, the Factory actually needs, but that probably has to wait until SJG publishes the relevant PDF supplement (although see my other thread, about that subject).


I'm not happy having a control room, since with only 60 control stations, they can't do much supervision of the habitats (keep in mind, I've assigned 700 cops and 300 administrators to work under the 60 top supervisors). I realize that a control room performs lots of functions, but I could probably have gotten away with splitting the module in half, with 1/3 control room being plenty for the needs of the station (the other 2/3 could be spend on refridgerated food, or fuel tankage for the auxillary craft).


12 hectares of recreational open land, for 37.5 people? That's 6.4 square meters per person, although of course hopefully they won't all want to use the open land at the same time. Note, though, that both the set of small establishments, and the set of large establishments, can each accomodate more than 90% the inhabitants at once (this is intended for major celebrations, such as Christmass, Eid or a military victory).

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Is this station built by a particularly hedonistic culture or one with sacred prostitution or something? It seems rather odd (from a 21st century American perspective) that large public spaces would be set aside for purely sexual uses, especially for group sex.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Have you thought of minifacs?

Perhaps not, steel is lousy protection against charged particles. And charged particles, not gamma rays, are your problem in a natural space environment (ie. not near atomic explosions). You ought to put a nice thick layer on the outside of something with low atomic number: water (ice), paraffin wax, hydrogen in nylon tanks, etc.

Be safe: Whipple plate.

Consider a few offices.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Neat, an O'Neill cylinder is remarkably well represented by the Spaceships rules.

This is why we can't have nice things.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

I think of America as the home of the swingers' club, the S&M bar, and the "Turkish" bath. Perhaps it is TV shows leading me astray. But anyway, I know there was a 'Hellfire Club' in Canberra when I lived there, and Canberra has about 300,000 people.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

I'm not sure what you mean by 'Turkish Baths' - as far as I can tell from Wikipedia and a few decades of experience being an American, Turkish Baths really aren't an American institution. As far as swinger's clubs and S&M bars, they definitely exist - but we don't devote 1/20th of a 38 thousand person town to them by any means. In fact, I doubt that we have more than one S&M/swinger's club for every fifty-thousand people.

I think it would make more sense if the sex-clubs were just Establishments at best.

Another thing I'd do is cut the Factory and replace it with a Habitat with Minifacs and more Cabins so you can fit more people on the station. Try and bring the price/person down to significantly under a million dollars.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

YES we do... its called (viva) Las Vegas!

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

I meant those famous "Turkish baths" in New York and San Francisco that were notorious in the '70s and '80s as gay sex joints.

Neither does this design: the shag shacks and orgy rooms are among many facilities in the zero-gee open space section. Courts for ball games were also mentioned, and other facilities were implied to exist.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

For cosmic rays and solar storm protons, you get a reduction of dose by a factor of about 2 for roughly every meter of shielding. For neutrons from nuclear sources (fission, fusion, radioactive decay), that goes down to roughly 10 cm if it is hydrogen rich material. 7.5 cm of steel will do very little to stop cosmic rays and solar storm ions, and it may scatter nuclear neutrons but will not tend to stop them.

To reduce the intensity of 100 keV hard x-rays by a factor of 2 you need about 1/3 cm of steel. For 300 MeV nuclear gamma rays, that becomes about 1.25 cm of steel, and for 1 MeV nuclear gamma rays, 2 cm of steel.

Net take home message - steel is good for gammas, but poor for particles.

Luke

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Perhaps a magsail would be the best protection against charged particles.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

It would need to be quite an extreme magsail. I have a magloop simulator I wrote, for simulating the deflection of protons by a magnetic field. For a configuration of two concentric magloops, one with a radius of 110 meters and one with a radius of 90 meters, each carrying 5E7 amperes, the loops will protect a habitat (or anything else) between them at 100 meters from their common center from protons of up to 1 GeV, but offers only partial protection against 10 GeV protons. This will protect against most solar storms, and give some but not complete protection against cosmic rays. With that separation and current, the loops will experience an attractive force of 25,000 tons per meter.

I make this program freely available on my website
http://panoptesv.com/Magtracer/magtracer.f
http://panoptesv.com/Magtracer/grater.f
http://panoptesv.com/Magtracer/rand.f
http://panoptesv.com/Magtracer/rungakutta.f
You will need to know FORTRAN to get much use out of it, and will need a FORTRAN 77 compiler (you can get one for free if you install cygwin on a windows machine, and I think linux automatically comes with a fortran compiler). It numerically integrates the trajectories of protons traveling in the magnetic fields of current loops. In its present configuration, it looks at the time inverse of the radiation protection problem - it starts the protons at the location of the habitat, and sees if they can escape to far away. If all protons are trapped, then there is no trajectory from far away which will allow the protons to reach the habitat. For those of you with programming experience, or who are willing to learn, you can use this to try to find effective magnetic radiation shields. Maybe YOU can figure out how to make it work more effectively!

Luke

EDIT: Make that an attractive force of 2,500 tons per meter, I forgot a factor of g=9.8 m/s^2. The attractive force goes as the product of the currents in the wire, so if both loops keep the same current the force is proportional to the square of the current. Reducing the current by a factor of 10 will give you a force of 25 tons per meter, which may be tolerable with sufficient support structures. This current will provide limited protection against 1 GeV protons and nearly complete protection against 100 MeV protons. This will provide considerable help but not complete protection against solar storms, but will let a lot of cosmic rays through.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

It is a leisure space station, where the 37500 inhabitants have 100% spare time (well, at least 98% spare time), and some of them will want to join the 24'000 mile high club (and in zero g), and they'll all be rich and healthy (and if not young then rejuvenated to the full extent of what TL9 medical science can do) ,so why not provide rooms made for the purpose, with systems to clean away all the mess? Much better than that they sneak off and try to do it in the Control Room (the only other zero-g facility).

That said, I'd guess that anywhere from 1/3 to 1/10 of the zero-g habitat module is devoted to shag cabins, depending on the culture and expectations of the designers, with most of those being small (actually cabin-sized). The rest is zero-g diving pools, ball game arenas, and so forth. And as someone pointed out, I probably should have gone with Habitat instead of Open space. That way, I'd get lots of tech crew, and the cost would feel more correct.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

It was designed for and built by sex addicts!

:D LOL

Other comment --
 

700 cops for 37500 is rather high.

In America, usually there's one cop on duty per 1100 folks.

That would be some 37 cops; x5 for shifts, holidays, sick days, vacations, etc. you're looking at about 185 police officers plus admin personnel.

If you need security guards ("prepare to repel boarders!") that changes things but that's a different category (armed forces v. police.)

The hospital bed count is a bit high too -- 1200 = roughly one bed per 30 people. I think a normal figure is about 1/5 to 1/10 this. In an epidemic the sick will probably stay in residences with visits by medical personnel.

Of course, given the sexual mania indicated by the focus on . . . playpens, you might need the extra cops and doctors to deal with the fallout.

Re: Other comment --
 

Probably some of the facilities are too heavily staffed. On the other hand, it'a a luxury habitat, and the habitants expect top-notch service and serious security.

One could also suggest that most of the hospital beds are used for elective procedures, rather than to treat diseases and injuries.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Good argument...

...but: It makes the high number of security personell look even worse. If your people are basically either employees or VIP#s, your need for normal police goes down quite a lot ;)

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Think of them as permanent hotel guests. Very wealthy, very permanent hotel guests.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

It could be used to attract tourists. It might be used by more visitors then residents.

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

Just a quick note on the Control Room thrusters - you could also move the habitat (for whatever reason) by tethering it to its complement of craft and having them pull it where it needs to go. Assuming each craft is capable of 1G acceleration, this would give the station a 1/31 G acceleration - rather slow, but probably enough that course changes could be done much less in advance than would otherwise be necessary.

I really like this habitat concept, although I admit I found the mention of "shag shacks" surprising (not surprising they would be there, but surprising the designers would make the habitat with them in mind). You might want to take a closer look at your armoring method, as others have indicated a susceptibility to charged particles. You might want to consider sacrificing some of the factory space to coat the habitat in a layer of ice, in addition to the steel for protecting against meteorite fragments. I'm not sure exactly how much ice you would need - any takers?

Re: [GURPS Spaceships] TL9 SM+15 Space Habitat
 

The Miner's Rest port in GREY LENSMAN?