[Spaceships] Questions for Open Space

[Pectus Solentis]

Well, is here anyone to explain Open Space Farms' rules?

[munin]

Originally Posted by Tyneras

…Unless you are intentionally making an Open Space less efficient (huge empty verticals)…

It's about mass, so it has nothing to do with empty vertical space.

My interpretation is that larger open spaces have deeper soil to support larger vegetation.

An SM+8 Open Space is 0.05 acres (~200 m^2) and 50 tons, or 250 kg/m^2. Soil is about 1,330 kg/m^3, so that's about 19 cm of soil (7.5 inches). That's enough for grass and flowers, but not for trees. Even most bushes want a meter or more for their roots -- with only 20 cm of soil, you could probably just push them over.

As the Open Space gets bigger, its increasing mass/area ratio allows the soil depth to increase to the point where it can support larger vegetation, like bushes and trees, eventually small forests with "bedrock" to shape terrain and hold water features.

[the-red-scare]

That’s good, and there’s also some scaling of the support structures and bracing for increasingly large open volumes. Technically that should apply to every system to some extent. It would be annoying to account for, though. But if an average SM+5 system is, say, 5% structure, an SM +15 system might be 15%. I once did the math using frame formulas from Atomic Rockets and tried to adjust performance and capacity but it was really more trouble than it was worth.

[Tyneras]

Originally Posted by munin

It's about mass, so it has nothing to do with empty vertical space.

My interpretation is that larger open spaces have deeper soil to support larger vegetation.

An SM+8 Open Space is 0.05 acres (~200 m^2) and 50 tons, or 250 kg/m^2. Soil is about 1,330 kg/m^3, so that's about 19 cm of soil (7.5 inches). That's enough for grass and flowers, but not for trees. Even most bushes want a meter or more for their roots -- with only 20 cm of soil, you could probably just push them over.

As the Open Space gets bigger, its increasing mass/area ratio allows the soil depth to increase to the point where it can support larger vegetation, like bushes and trees, eventually small forests with "bedrock" to shape terrain and hold water features.

The majority of trees can survive fine in 1 foot of soil or less as long as they don't have to contend with strong winds. Rocks can be hollow. Crops tend to be short. There is no reason beyond the designers of the ship failing at Engineering (Starship) rolls for OpenSpace to be that inefficient.

But I'm fine with treating the RAW Open Space as a high ceiling luxurious open area, and the Efficient Open Space as densely packed greenhouses and low ceilinged park areas. I've been to people's houses that were like that.

[Pectus Solentis]

Originally Posted by the-red-scare

But if an average SM+5 system is, say, 5% structure, an SM +15 system might be 15%.

Why? The assumption that GURPS Spaceship employs is all of the system is 5% of the complete spacecraft. So 20 systems make 1 complete spacecraft. Isn't it?

[the-red-scare]

Originally Posted by Pectus Solentis

Why? The assumption that GURPS Spaceship employs is all of the system is 5% of the complete spacecraft. So 20 systems make 1 complete spacecraft. Isn't it?

Yes, what I mean is that there aren’t systems for “structure,” so the spacecraft’s actual frame is presumably divided up and invisibly included in each system. However, bigger ships require a heavier frame to achieve the same acceleration (or land on the same planets, or whatever). That means a larger and larger portion of each system should technically be devoted to structure rather than the system itself, which means capacity and performance of those systems should slowly drop the larger a spacecraft gets.

[Pectus Solentis]

Originally Posted by the-red-scare

Yes, what I mean is that there aren’t systems for “structure,” so the spacecraft’s actual frame is presumably divided up and invisibly included in each system. However, bigger ships require a heavier frame to achieve the same acceleration (or land on the same planets, or whatever). That means a larger and larger portion of each system should technically be devoted to structure rather than the system itself, which means capacity and performance of those systems should slowly drop the larger a spacecraft gets.

Well. understood.

[Tyneras]

A side note on the farming aspect of Open Space. I've seen estimates on how much land it takes to feed a person with modern TL8 tech. The range goes from 2 acres to 0.1 acres, but most seem to be in the range of 1 to 0.25 depending on assumptions about climate and exact set up.

Obviously UltraTech can do far better with gene-engineer super crops.

Just for fun, lets assume our ship has TL8 farming and the Efficient Open Space systems. At SM +8 habitats have 6 cabins, designed for up to 12 people. The EOS has 1 area, 0.05 acres. Even at the low end of the spectrum (0.1 acre per person) you need 24 systems of open space to feed everyone. The systems scale at the same rate as each other, so no need to change the ratio for larger ships.

Oof. That's a bit more than 1 cargo bay, Captain Janeway. Let's hope TL9+ crops are significantly more productive.

[Pectus Solentis]

Below is my Prospector Pioneer Mothership.
(Prospector is name of a state.)

*SM+13, Loaded Mass 300,000ton, TL11
*3950 people capacity (350 people to operate)
*45 people work for maintenance. (Highly automatized)
*Front
**System 1 : Armor, Metallic Laminate, dDR 70.
**System 2 : Science Sensors Array : Sensor Level 15
**System 3 : Open Space, 2.5 acre of Farms
**System 4 ! Nanofactory, 300M$/hr
**System 5 : Habitat, 2000 cabins : For crews who operate vessel and survey systems. 350 people uses this.
***100 cabins, 1 Large Ops Center (Mission Command) : 20 administrative staffs work.
***500 cabins, 5 Large Ops Centers (Scientific Instrument Survey) : 20 analysts per Ops Center.
****Each of the Ops Centers is used for [Chemistry], [Geography (Physical)], [Geology], [Meteorology], [Physics].
***300 cabins, 3 Large Ops Centers (Direct Planetary Imaging) : 20 analysts per Ops Center.
****Each of the Ops Centers is used for [Cartography], [Biology], [Geography (Political)].
***600 cabins, 3 Major Labs (Planetary Landing Survey) : 20 Scientists per Labs.
****Each of the Labs is used for [Chemistry], [Biology], [Geology].
***300 cabins, 3 Hosiptals : 20 Medical agents per Hospital.
***2 cabins, 1 Retail Stores : 1 Clerk works.
***8 cabins, 4 Gyms : 4 Trainers work.
***175 cabins, 175 Cabins : For bridge crews and maintenance crews, and the people who use Ops and Labs and who operate Establishments.
****320 people (officers 30, enlisteds 290) use this cabin.
***15 cabins, 15 Cabins : Operating crew of the landing boats, or the armed agents who escort the landing survey teams
****Up to 30 people use this cabin.
**System 6 : Habitat, 2000 cabins : For pioneers. 3600 people uses this.
***1800 cabins, 1800 Cabins
****3600 pioneers uses this cabin. Crews who operate the below facilities included.
***100 cabins, 50 Classrooms
***20 cabins, 10 Nursuries
***20 cabins, 10 Retail Stores
***20 cabins, 10 Gyms
***40 cabins, 1 Open Space, 0.05 acre of Gardens : Consists of 6 floors.
**Core System : Control Room : C11 Computers. 30 people can gather. The personnels below (total 15) works here.
***Captain 1, Pilot 1, Navigator 1
***Engineer 1, Maintenance Leader 6 (each is for maintaining housed vessels, Nanofactory, Life Support systems, Sensors, Engines, Commodities)
***Sensor Operator 1, Traffic Controller 1 (for recovering and launching housed vessels)
***Escort vessel controller 1, Administrator for human resources affairs 1, CEO of the pioneer company 1
*Central
**System 1 : Armor, Metallic Laminate, dDR 70.
**System 2 : Cargo Hold, 15,000tons
**System 3 : Hangar Bay, 10,000tons
**System 4 : Hangar Bay, 10,000tons
**System 5 : Hangar Bay, 10,000tons
**System 6
***System 6-1 ! Weapons, Tertiary Battery, 30MJ Very Rapid Fire Improved UV Laser Turret * 20 : For flak defense. I'm Considering replace these turrets to Tractor Beams.
***System 6-2 : Fusion Reactor (Dedicated to System 6-1)
**Core System : Fusion Reactor (2!)
*Rear
**System 1 : Armor, Metallic Laminate, dDR 70.
**System 2 : Cargo Hold, 15,000tons
**System 3 : Hangar Bay, 10,000tons
**System 4 : Hangar Bay, 10,000tons
**System 5 : Hangar Bay, 10,000tons
**System 6 ! Reactionless Drive with Singularity Stabilizer, 1G.
***My house-rule system that Reactionless Drive, Contragravity Lifter, Stardrive are combined.
**Core System : N/A
*Costs 72,859.15M$
*The starship has artificial gravity and gravitic compensators.
*Unstreamlined.
*When orbiting a planet, this ship can be treated Class III Starport limitedly.

I wondered if this 0.05 acre of Gardens is able to house 100 people comfortably.

When I compared SM+8 Open Space and SM+13 Open Space, I realized 1 area of SM+8 Open Space equals 6 cabins as both of these own 1 systems and SM+13 Open Space equals 40 cabins. So I decided my 0.05 acre of Garden (1 Are of Open Space) has 6 floors of indoor gardens. This made my mind peaceful.

The remained question is

Originally Posted by Rupert

I doubt that the intention is that a farm should be both producing lots of food and have space for 100 people to hang out.

Can people take a rest on the Farm? When people can do, then the use of Garden in my vessel will be vanished.

[Rupert]

Originally Posted by Tyneras

A side note on the farming aspect of Open Space. I've seen estimates on how much land it takes to feed a person with modern TL8 tech. The range goes from 2 acres to 0.1 acres, but most seem to be in the range of 1 to 0.25 depending on assumptions about climate and exact set up.

Obviously UltraTech can do far better with gene-engineer super crops.

Just for fun, lets assume our ship has TL8 farming and the Efficient Open Space systems. At SM +8 habitats have 6 cabins, designed for up to 12 people. The EOS has 1 area, 0.05 acres. Even at the low end of the spectrum (0.1 acre per person) you need 24 systems of open space to feed everyone. The systems scale at the same rate as each other, so no need to change the ratio for larger ships.

Oof. That's a bit more than 1 cargo bay, Captain Janeway. Let's hope TL9+ crops are significantly more productive.

Hydroponics systems are supposed to need about 200 ft^2 per person, which means about 10 people per open space. That's in the ballpark for SM+8 ships. For larger ones, there comes a problem in the RAW, because of the slower growth of Open Spaces.