My previous posts about my new starship construction system generated a bunch of interest and several people expressed a desire to see more. So I thought I’d post up bits and pieces of this over a series of posts. I’ll start by posting the things that are new relative to the starship construction system in the Star Frontiers Knight Hawks Campaign Book.
I already posted the introduction the the “A New Starship Construction System” post back in early November. Although it wasn’t labeled as such, the “Starship Engines” post that came shortly after the first one was part 2 as that was taken from the new system as well.
The timing of these posts will be probably be fairly sporadic as I’m using them as filler between posts on other topics and when I’m working on things that I’m not ready to post about.
I’ve already posted about the engines. The next major change is the life support system which is the topic of this post. With each of these posts going forward, I’ll try to include some of the rationale and thinking behind the choices I made and the way I designed it. So let’s get going.
One of the things that I found problematic with the life support system as described in the standard rules was that it always felt way too small. For example say you had a ship that could support 9 people. According the the standard rules, all of the life support equipment for the entire ship, including all the food, oxygen, and water for 200 days of operation would weigh only 9 kg (20 lbs)!
That 9 kg is split half and half between the equipment and the consumables so there is 4.5 kg (10 pounds) of equipment to get all that food, water, and air throughout the ship and then 4.5 kg of the food and water itself. Now I don’t know about you, but there is no way I can feed my family of 9 for a week, let alone 200 days on 10 lbs of food. Maybe if it was all just a nutrient pill that you took once a day that had all your calories, vitamins, and minerals. But I think even that is stretching it and definitely not very satisfying.
One could argue for transmutation/replicator technology ala Star Trek but that just doesn’t jive with the feel of Star Frontiers for me and I don’t want that in my game. Beside the rules state that the life support systems “include food storage and preparation, and water, atmosphere and wast processing and disposal.” (KHCB p 14) That sounds like it should include a bunch of machinery and storage space.
So looking at the life support systems I saw two things that needed to address. One was food storage and preparation, and the other was water, air, and waste circulation and processing. All of that was going to take up space. I needed to make sure the system had enough mass and volume associated with it to include all the various bits of machinery and storage and pipes and duct work needed to get the various bits around the ship as needed.
Another aspect was that I wanted it to be completely configurable by the ship designer. The default rules were for a 200 day supply in the system. Since I knew this new system was going to be bulkier, I wanted to give the option to go for a smaller system if you knew that was all your needed. For example, a shuttle, that just goes up and down from the ground to orbit probably doesn’t need a life support system that can go 200 days without recharging. It probably only needs a few days at most and so can have a much lighter system.
Related to that I wanted to have different types of system for shuttles, system ships, standard interstellar ships, and first class accommodations. Each of those have different requirements and therefore should have different costs, volumes, and masses.
Taking all of that into account results in the following system. The excerpt of the rules that follows assumes that you’ve determined the crew size and number of the various passenger cabins you will have on the ship before to select the life support system.
Life Support Equipment
Now that you know the number of crew and passengers, you can select the amount of life support equipment the ship needs. It is recommended that you have at least one backup life support system in case there are problems with (or damage to) the primary system. The life support system includes a variety of systems such as air filtering and circulation, food preparation, sanitation facilities, and waste management. Life support on starships are mostly a closed system, almost everything gets recycled. However there are some consumables that do need to be replaced (mainly foodstuffs) every so often.
Your life support system needs to be at least large enough to support the crew and passengers. Typically, ships are designed with a little extra capacity as a safety margin or for emergencies. There are four basic levels of life support available for ships, depending on the ship’s needs:
Rudimentary – This is an air supply system only. It doesn’t handle food or waste materials and just provides an air supply and air circulation system with filtering. This is the life support system you find on launches, workpods, fighter craft, and other ships that are not designed to be occupied for a long time.
Basic – This level of life support adds basic food storage and preparation, sanitation facilities, and waste management to the air supply system of the rudimentary life support level. Supplies are stored and consumed and waste material has to be removed regularly. There is little to no recycling of materials except for air and water. This level of life support is typical of shuttles and some short distance system ships that typically operate for only short periods of time between calling on bases where their life support can be resupplied and waste material removed. It may also be found on some lifeboats. While you could equip a starship with this type of life support system, making it large enough to support long missions uses up valuable space in the ship and tends to be more expensive in the long run.
Standard – This is the typical system for any starship. It consists of complete air and water recycling, as well as recycling of waste material. It typically includes some sort of hydroponics system for both growing fresh food and recycling carbon dioxide back into oxygen. There are full food preparation facilities as well as complete sanitation facilities. This level of life support is required for Journey class passenger accommodations.
Deluxe – This is a more advanced version of the Standard system. It provides better recycling, larger food preparation facilities, more variety in the fresh foodstuffs, and better (nicer) sanitation and waste management facilities. This level of life support is required for any First Class passenger accommodations.
A ship can have different life support levels for different parts of the ship. This is quite common on passenger liners. For example, if a passenger liner has 20 First Class cabins and 100 Journey class cabins. It is not very likely that the owners will invest in Deluxe life support for the entire ship (although if they did, it would figure prominently in their advertising). Rather they would invest in a Deluxe life support system to cover the First Class cabins and a standard system to cover the Journey Class cabins and the crew.
The volume listed for the life support system includes both the machinery and hardware for processing the air, water, food, and waste material as well as storage space for raw materials and duct work to move material around the ship.
Every life support system has two ratings. The first is the maximum number of beings the system can support. This determines the amount of mass and volume allocated for the life support machinery (pumps, filters, ducts, pipes, etc.). The second is the maximum number of days that the system can support those beings without being refilled/recharged. This determines the amount of volume committed to storage of life support supplies.
Base hardware costs and volumes per being supported
All values except base system volume are multiplied by the maximum number of beings the system can support at one time.
|Type||Cost||Mass||Base system volume||Volume|
|Rudimentary||500 cr||0.2 tons||1 cu m||0.1 cu m *|
|Basic||1500 cr||2 tons||6 cu m||5 cu m|
|Standard||3000 cr||4 tons||15 cu. m||8 cu m|
|Deluxe||5,000 cr||6 tons||30 cu. m||10 cu m.|
* This volume assumes you are equipping a small one or two room craft with this system like a fighter or launch. If you try to put this into a larger ship the volume goes up by a factor of 10 for the ducting and pipes needed.
For example, our passenger liner has 20 First Class cabins and 100 Journey class cabins for crew and passengers. It would need two life support systems. The Deluxe system would support 20 beings. It would cost 20 x 5000 = 100,000 cr, have a mass of 20 x 6 = 120 tons, and take up 30 (base volume) + 20 x 10 (volume per being) = 230 cubic meters. The Standard system for the Journey class cabins would cost 100 x 3000 = 300,000 cr, have a mass of 100 x 4 = 400 tons and take up 15 + 100 x 8 = 815 cubic meters. Thus the Standard system while being just a little more than 3x the size of the Deluxe system, supports 5x as many beings.
Supply cost per being per day
In addition to the base machinery costs, there is the cost of the food, air, and water needed for the beings on board. Multiply each value times the maximum number of beings the system can support and then by the number of days you want to be able to support those beings without a reload/refill of the system.
|Rudimentary||10 cr||0.05 tons||.1 cu m|
|Basic||15 cr||0.15 tons||.4 cu m|
|Standard||25 cr||0.1 tons||.15 cu m|
|Deluxe||40 cr||0.15 tons||.25 cu m|
So if our passenger liner wanted to support its full complement of crew and passengers for 200 days without a resupply, the cost of the supplies and storage areas would be as follows: For the Deluxe system the cost is 40cr x 20 beings x 200 days = 160,000 cr, the mass would be 0.15 tons x 20 x 200 = 600 tons, and the volume would be 0.25 cu m x 20 x 200 = 1000 cubic meters. The standard system supplies would cost 25 cr x 100 beings x 200 days = 500,000 cr, the mass would be 0.1 tons x 100 x 200 = 2000 tons, and the volume would be 0.15 cu m x 100 x200 = 3000 cubic meters.
Thoughts and Comments
That’s the life support system rules in the the new system. Let me know what questions or thoughts you have in the comments below.