How can a long-haul budget transport spaceship be limited on water?

I suppose you could use any rationale you want if having water be limited is an important plot point. Maybe the storage tanks were holed by something and some of the water supply vented to space? You could theoretically recycle water, O2, carbon etc very well with close to 100% reclamation and recycling if the system is designed with minimal leakage, but if some of the mass is lost to an accident, conservation would become vital until the ship could replenish its supplies. Priority would have to be given to the ship's hydroponics (or whatever else is taking CO2 out of the air and generating food and O2) for plant growth and photosynthesis. Water is critical for photosynthesis and O2 generation.

CindyRae said:

Trying to figure out what makes sense.

Is it feasible to have a long-haul budget transport spaceship to have limited water for the passengers?

I was switching off the lack of water as a ship danger per others' comments in other posts in SYW, Research, and here on the scientific validity, but it's a more important thread to the story than I thought. It will be hard to pull out.

Maybe most of the water is used as shielding? Or the reclamation units fail/has problems? Or the water "generation" from hydrogen, oxygen fails/has problems?

...such that passengers don't shower often and are smelly, beards are grown, on-board gardens are carefully tended, people are hyper about reclaiming anything spilled, etc.

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Every gram counts, so I suppose at some point the ship's provisioners will have to limit the amount of water they take. Generally tho, they'd err on the side of not letting everyone die of dehydration. But I think you can handwave in a reclamation/generator fail pretty easily without the reader being too irritated.

My assumption is that on space flights in general, passengers would be encouraged not to shower & be paranoid about recycling everything. Just watched this video last night, which discusses lots of the things you're mentioning.

I'm not exactly sure what you're asking CindyRae, but I will try. Water is generically not easily destroyed and can be made but at the expense of burning hydrogen and oxygen. Water is a more volumetrically efficient way of storing oxygen/hydrogen, but with high energy costs to get the gases back. I can only think of one thing that you could contaminate water with that would be challenging to recycle and that's deuterium (heavy water used as radiation shielding). You can contaminate water in ways that make it undrinkable and the tech to render it safe varies depending on the contamination. In general Distillation, Electrodialysis and Reverse Osmosis are common recycling techniques. You could, however, treat water and it could end up tasting like crap, smelling terrible, looking awful, and still be safe to drink. You might have to hold your nose and only drink it to survive while avoiding it for all other purposes.

If its a real water shortage issue it reminds me of the Fremen's stillsuits from Dune. Don't shed a single tear. Maybe just barely enough water for drinking. You might have a scenario where the recycling equipment is damaged and can make water that is only usable by plants and for cooling systems. A distallation system could be MacGyvered together but its a slow process and just barely makes enough for drinking only.

In one of the Battlestar Galactica episodes, explosions in the flagship's water tanks caused water to spew away, leading to an emergency water shortage. IIRC that was a sabotage. You can have a similar incident, or an accident. Alternatively, maybe some of the water tanks are contaminated by bacteria or radiation (both can be dealt with in time but may cause a short-term emergency) or taken hostage by some terrorists or an emotionally disturbed guy who has just been dumped. Or, you know, like some American budget airlines, they charge cheap for the seats, but everything is extra. "Can I have a glass of water?" "Sure, ma'am, two hundred dollars." Those who can't pay will be tasered and put into stasis.

Since you are talking about hundreds of years into the future, and about a spaceship which is expensive to build, I don't think using water for radiation shielding is practical. According to this article, you are looking at 1m thick of water for radiation shielding. This will substantially increase the hull's surface area and the ship's volume, thus increasing the construction cost and potentially fuel consumption. I'd envisage they use some sort of heavy metal compound gel in lieu of water. If the ship travels FTL, maybe even some sort of artificial magnetosphere.

Hydrogen and oxygen are common elements, but not in concentrated pure forms. You are probably on more plausible ground if you’re mining ice — though I’d guess most cometary or planetoid ice is pretty dirty, impure stuff? Also, mining anything takes power, equipment and equipment (that breaks down); heating and distilling water from ice takes power & etc. Just some wrinkles to consider.

*Several minutes of hysterical laughter*

Let me tell you a story, dear children. It's the story of the time a whole damn aircraft carrier went a whole month without any goddamn potable water.

We were in port, doing the kind of long-term maintenance that involves opening up large pieces of equipment and scrubbing them out and changing filters and such like. Large equipment such as the ones that turn sea water into potable water. (They were the reverse osmosis style, which sounds very cool until you find out what it is and are bored to absolute tears.) Anyway, there was a natural disaster and we had to dash out to open water as fast as we could go. Now, these machines are very large, and prominently placed in the engine room, and anyone who isn't part of reactor department is only vaguely aware that they even exist. So, in the panicking and running around, they were forgotten. And no one remembered until we were already several hours out, when we realized that some parts had been taken out to the shipyard for some repairs.

We couldn't turn them on. We couldn't make water. The ship had tanks which were still full with water from when we had been parked, but we couldn't make any more. Some words were said which should not be repeated in polite company. Water was immediately rationed. This would be fine, we assured ourselves, because our flight to safety had been a massive over reaction and we would be back in port in a few days.

Guess what happened next.

Yeah, we weren't back in port in a few days. Now, it's late March, in the Pacific Ocean, flirting with the equator. It's hot. It's hot like a vulgar metaphor. And no one has been able to shower in days, and then weeks. No laundry. Chow was on paper plates, and it was all cold, because if they'd cooked they would have had to wash the pans. And what that gets you, kids, is mad. 3000 people (The air wing stayed ashore to take their chances with the disaster that never made it to our end of the island) and every one hot, and sweating, and smelly, and sitting in crusty clothes eating room temperature bologna sandwiches. And we were alternating between sugar highs and crashes, because while the bottled water ran out quick we had a full load of sodas and energy drinks (Priorities.).

I have no idea what the fellas did (And probably don't want to) but the girls rapidly developed a black market of dry shampoo and baby wipes, and Febreezed the crap out of each other. The sinks still ran (As did the commodes) and your best bet was to get a rag wet and wipe down what you could while still in your uniform.

The moral of the story is that a simple mechanical failure, of even a minor component that you see every day but take for granted, can make life very, very uncomfortable for a lot of people.

I was just going to point out that the US Navy has this thing called "water hours" even on the largest ships. "Water Hours" are when they turn on the water to the showers , usually only for an hour or so per day (if you're lucky) and you can shower. If you're right at the end of water hours you can find yourself covered in soap and no way to rinse (ask me how I know this). This is in the middle of an ocean, mind you. Should your water plant break down water hours get cancelled and you just stink till it gets fixed or you make port. Even drinking water gets rationed. So should your water plant on your spaceship quit, people could get very thirsty and very, very smelly. Also very short tempered.