General Emergency Lifeboats?

[Spinward Flow]

You could pay it forward, and keep a stock of spare parts.

That requires cargo space.

150 person/weeks of life support costs Cr150,000 and requires 1 ton of cargo space. (CT Beltstrike, p3)

2. Life Support.
Each occupied stateroom on a starship involves an overhead cost of Cr2000 per trip (two weeks) made.

2 person/weeks (equals 1 person for 2 weeks) of life support costs Cr2000 and requires 0.013333333333333 tons of cargo space (which is sufficiently negligible that it becomes a "rounding error" when talking about 2 weeks worth of supplies and thus rounds down to zero tons for simplification).

For anyone who wants to get too pedantic about it, 0.013333333333333 tons of displacement amounts to all of 186.666666666 liters of volume, which "isn't much" when 1 ton of displacement is valued at 14,000 liters of volume.

Point being that short term life support (read: single jump worth endurance of 2 weeks at commercial operations tempo) is small enough to be subsumed into the "4 tons per stateroom" basic construction rules for starships. If you want longer life support endurance, you're going to need to spend cargo hold capacity for the privilege of storing those (extra) life support consumables.

 

[Spinward Flow]

What's interesting is that there's no real treatment of any kind of requirement for lifeboats. I think that the expectation is that if anything sufficiently catastrophic happened, it's, well, catastrophic and there's no need for lifeboats. I don't know if there's much talk about emergency life support, which is arguably a better take on the problem than lifeboats. Spaceships don't sink, they just lose air. They don't capsize in high seas or high winds, or take on water. It may well be easier to patching escaping air than incoming water.

So, a practice of emergency repair, auxiliary backups for life support and sheltering in place is likely a better practice than lifeboats.

 

[Badenov]

So, there kind of are rules on this already, at least in Mongoose, which is the version I own. In the Spacecraft Design section, in the Staterooms subsection, is indicates the stateroom's tonnage includes the life support equipment needed to keep the crew alive. A bit harder to find, in the Spacecraft Operations section, Life support subsection, under the Suffocation heading, it says a spacecraft with power can sustain one person per stateroom for a month comfortably, and for six months, presumably uncomfortably. For ships without staterooms, like shuttles, you still pay 1.5T for a seat. But one person for a month is 1x30daysx24hrs = 720 person-hours of life support.

The most people you can get into a shuttle in anything approaching safety is to use the passenger seat from the Military Vehicles supplement, in which a loaded seat is 100kg (the volume taken up is much less than a tenth of a dTon, so is not the limiting factor), so you can get 10 seated passengers per ton. You may be able to cram more in, depending on their actual mass, but not a lot more, unless they're all skinny. The crew seats for small craft in High Guard are 1.5T, mentioned above, and presumed to include the listed life support. The Mil Vehicles seats do not come with life support, that's purchased separately in the Mil Vehicles book, but it's not too important, because at 10 people per ton, with just the pilot's seat/cabin, you've got 720 person-hours, so 72 people for 10 hours, or however you divide it up, and a total of 60 hours, with stinky air, which is fine if the alternative is breathing vacuum. And so a rescue shuttle can be just about anything with the space for 10 people per ton.

That all said, if you stuff a modular cutter full of 300 refugees, that's 2.4 hours of clean air and 14 .4 hours before the stale air runs out. But you can go a good distance at Thrust 4.

 

[Condottiere]

I wouldn't put too much faith in Mongoose life support figures.

As I recall, an oxygen bottle has four hours, so surviving on fumes for the next half year would require some form of explanation, besides it's still switched on.

Because, life support is one of the big operating cost(s) on spacecraft, at least in Traveller.

 

[Badenov]

Well, a ton and a half for just a person and a chair, or 2T for a stateroom, I figured 'life support' presumes some manner of active air recycling, not just a 4-hour bottle of canned air. Otherwise how do you spend a week in jump and days getting to a planet without suffocating?

 

[Condottiere]

I don't think it's ever been explicitly stated, but you pay it forward.

 

[whartung]

Spacecraft Operations section, Life support subsection, under the Suffocation heading, it says a spacecraft with power can sustain one person per stateroom for a month comfortably, and for six months, presumably uncomfortably.

I wouldn't put too much faith in Mongoose life support figures.

"With power" which suggest recyclers and CO2 scrubbers are operational.

My premise is that I don't think ships, particularly civilian ships, tend to just outright explode. Even with a fire, I don't think there's a ticking bomb heading toward explosion. Thus there's little need for mass egress for most ships, the ship itself is a better life raft. Life support is nowhere near as power intensive as many things on the ship. Having redundant power with simple enough systems that engineering can do in place repairs seems to be the better path forward.

A 200 ton Free Trader can have as much as 40 people on board (10 staterooms, 20 low berth). The 20 ton launch can probably carry 8 (including the crew of the launch). The Trader would have to dedicate almost 40% of volume to carry 4 boats. Or you can just write off the low berth folks and carry two. If the low berths have power, then there should be enough power for life support to maintain the people on board by staying in place. If they don't have power, the low berth are probably dead anyway.

Mind, these are stock designs, but even still, Book 5 has 1/2 ton per person for small craft.

Finally, it seems none of the stock designs have made provisions for lifeboats. The Subsidized Merchant and Liner both carry a single Launch, but neither of those is adequate enough for the populations on board.

"Everyone in Vacc suits, we'll tether together, float nearby, toggle the beacon and wait for the fleet!"

 

[Condottiere]

There are lots of ways to provide continuous, cheap life support for humans.

This isn't jump drive engineering.

But if it's stated you pay once, and you could get seven months worth, why wouldn't more stingy skippers tinker with it to ensure maximum utility? You have the corridors (and staterooms) full of plants to make up the difference.

This is one of the game concepts where you have to explain how it works.

 

[whartung]

Because plants are fiddly, high maintenance, messy. Centralized HVAC for the win.

 

[Condottiere]

Do it properly, they regenerate and are practically free.

You can then introduce the mushroom drive.

 

[Spinward Flow]

Do it properly

Agree.

they regenerate

Well ... within limits ...

and are practically free.

Um ... ... wrong ...?

 

[Condottiere]

Since we aren't growing marijuana, I would suspect that the power bill would be more like that of a vertical farm, since we'd be aiming for maximum density.

 

[kilemall]

Hard vacuum, dead plants, no regen.

 

[Condottiere]

I'd layer life support, so that it would require catastrophic damage to rake out everything at once.

in which case, there probably would be no one left to take enjoy it, in such an event.

 

[kilemall]

I'd layer life support, so that it would require catastrophic damage to rake out everything at once.

in which case, there probably would be no one left to take enjoy it, in such an event.

In my CT/HG damage system, I have life support take damage through hull hits. The idea is that the systems are located in the floor/ceiling/wall in between space as a fraction of the stateroom budget and is highly redundant, powered by RTGs and virtually the last thing to go before the ship is destroyed or breaks apart.

The other rational damage result would be stateroom destruction.

 

[Condottiere]

You could have an altar, and light oxygen candles, for the next fortnight.

 

[mike wightman]

And how do you remove the carbon dioxide?

 

[G. Kashkanun Anderson]

Hard vacuum, dead plants, no regen.

Not. Necessarily.

There are lichens, at least, that can survive exposure to vacuum conditions for at least 18 months:

Lichen Vitality After a Space Flight on Board the EXPOSE-R2 Facility Outside the International Space Station: Results of the Biology and Mars Experiment - PubMed

As part of the Biology and Mars Experiment (BIOMEX; ILSRA 2009-0834), samples of the lichen <i>Circinaria gyrosa</i> were placed on the exposure platform EXPOSE-R2, on the International Space Station (ISS) and exposed to space and to a Mars-simulated environment for 18 months (2014-2016) to...

pubmed.ncbi.nlm.nih.gov

 

[spank]

And how do you remove the carbon dioxide?

Start with hydrogen, which is ubiquitous in Traveller.
Combine with the CO2 and a catalyst, get water and methane.

 

[spank]

Start with hydrogen, which is ubiquitous in Traveller.
Combine with the CO2 and a catalyst, get water and methane.

.
Works well enough for the ISS.
NASA estimates a human needs ~1.85 pounds of oxygen per day, and produces ~2.3 pounds of CO2 per day. So, you'd need a little under a liter a day, assuming you have liquid oxygen. Assuming there is no effort to reclaim the O2 from the water, You'd need need 2 55 gallon drums of liquid oxygen for 1 person for 1 year. Food and water would be bigger concerns, IRL life rafts often include survival food bars, which are basically flour oil and sugar, These give about 2500 calories per day, and measure about 350 cubic centimeters, You could approximate that to 1/3 liter per day of food, Water usage is often quoted at 2.5 liters per day, So you need about five 55 gallon drums of water per year.
From messing about modeling crates and barrel for I know that a 55 gallon drum is approx 60cmX 85cm, and you can easily stack 4 of them in a 1.5m square, such as a deck plan square. If you stack them 3 high you are only a little under 2.5 meters, or 1/2 a dTon. that's 12 drums, and you'd only need two for oxygen plus 5 for water and 1/2 a drum for food.
.
7.5 drums out of 12. So I think you could safely assume 1/2 dTon per person per year for "canned" life support. That doesn't account for any kind of air processing to remove CO2, but I think you could fit that in another 1/2 dTon, and get 1dTon per person per year. Which is alot worse than Spinward Flow's ~3 years per dton, but there is also very little effort to optimize, IE 55 gallon drums rather than efficent use of space, no recycling, etc.