Space Waste: The Future of Plumbing

Space Waste Throughout the history of humankind, we’ve looked to the skies in the hopes of finding out the future.

The theme for World Space Week 2023, “Space and Entrepreneurship”, recognises the growing significance of the commercial space industry in space, and the increasing opportunities for space entrepreneurship.

What does the future of plumbing look like? Does the answer lie in outer space? How do astronauts use the toilet?

To answer our questions, our Marketing & Membership Coordinator Rhia sat down for a talk with Grant Anderson, P.E President and CEO, co-founder of Paragon Space Development Corporation.

Paragon Space Development Corporation is one of the main corporations involved in the development of a Closed Loop Environmental Control and Life Support System for space missions.

The system also collects, processes, and stores both waste and water produced and used by the crew—a process that recycles fluid from the sink, shower, toilet, and condensation from the air.

How does it do that? Check the diagram below and read ahead to find out.

Space Waste Rhia: Waste on the International Space Station is integrated into the Closed loop Environmental Control Life System (ECLSS). Could you give me an elevator pitch for a Closed-loop Environmental Control Life Support System?

Grant: Humans need to have an environment where we can live. Generally speaking, we have a rule of 3: 3 seconds is the time for your body to implode in space, 3 minutes is how long you can remain conscious underwater before you drown, 3 days is how long you can survive without water before you start to die of dehydration and 3 weeks is generally how long you can survive without food.

Space is not a natural environment for humans; people need water, food and air to survive, and space doesn’t have those things. Using an ECLSS on the International Space System means all of those things are supplied, at a comfortable temperature.

G: As a closed-loop system, an ECLSS works to purify and reuse your air, your water and your waste. This works to recover drinkable water from urine, and to provide temperature control to the crew.

R: To my understanding, the astronaut crew is trained not only on how to use the ECLSS, but to also repair it if needed. Is Paragon involved in this training?

G: Yes, we do basic training and basic maintenance. In general, when we deliver flight hardware, we write an operations manual, a training manual and an emergency manual. So, if something goes wrong, some indications, what are the first things you do? And that’s required for safety and used in the training. Very often, we provide an extra unit to NASA or to a company so that the astronauts can actually touch real hardware. We may get to the point where you put on VR glasses and train that way, but there’s nothing really as good as being able to actually touch the hardware and understand how it works.

R: I think our apprentices would understand that and agree with that.

G: That’s why you have an apprentice programme. Nobody’s going to learn plumbing from just reading it from a book.

R: Yeah, you can’t just YouTube it, unfortunately.

R: So, NASA is wanting to push space exploration beyond Low Earth Orbit, resulting in longer missions. What changes need to be made to the current ECLSS to achieve this?

G: There’s one concept called closure, which is important. The farther you get away from resupply, the more the better off you are that you recycle as much as possible. To a certain extent it’s a complex trade off because it usually takes more machinery to recycle things and get them more closure, and that machinery can break, so there’s some point where it almost makes more sense to just rely on supply.

G: In general, we try to aim for longer missions, like going to the moon for long period of time, going to Mars, of having about a 98% closure rate, which means you lose about 2% of your water oxygen, whatever it is as you go forward; that generally means that the amount you have to take with you to replace that is small enough that you can design it into a spacecraft.

G: This is ever-changing though, because as launches become cheaper, it may be cheaper to not close as much and then just rely on essentially a rocket catching up with you and refuelling you every once in a while. A little bit like how aircraft that have a short range [to] make it across the Atlantic, they bring up a tanker and fill you up every once in a while.

The other thing is maintenance and reliability. The interesting thing about the space station is it’s only 30 minutes from Earth. You know, it’s 100 and 82150 miles up. But if you have to escape quickly because something goes wrong, to get in the capsule, detach, wait until you get over a good place to land and then deorbit and land, it’s about a 30-minute process. When you get to the moon, it’s a three-day process.

G: If you’re halfway to Mars, it may be a 30-month process to get back. The way that you determine how to maintain things and how much it won’t break has to keep going up. So, the Space Station has what’s called another acronym, ORU, it stands for Orbital Replacement Unit. It’s a little bit like, “what is the minimum size of the thing you have to replace to fix something that goes wrong if the pump goes wrong?”

G: Generally, with the Space Station, you take out the whole pump package and it gets shipped down to Earth. Then you have a new one shipped up and you stick in a new pump package. Those things can be like 200 kilograms.

They can be pretty big. That doesn’t work on the way to Mars because you have to bring your maintenance material with you, your replacements can be pretty big.

G: That doesn’t work on the way to Mars because you have to bring your maintenance material with you, your replacements, your spares, so you’d have to carry 3 new 402-hundred-kilogram pumps.

Space Waste G: In order to make sure you can make it all the way there with the weight, they break in the worst-case scenarios of reliability. What we have to do, going farther from Earth, is make the maintenance items smaller and smaller and smaller.

If you had to replace your whole toilet when the gasket on the stopper breaks in the back, you’d rip out the whole toilet off the floor and put a new one every time. That’s kind of how the Space Station works right now.

G: In reality, it may be you just have to pull off the bottom ring and replace that.

You could stack 15 of those in your in your closet and repair it. You’re not going to stack 15 toilets somewhere in your house just in case, right?

G: Those are the big things that have to change, food and food packaging is big. When a spacecraft detaches from the space station, the vast majority of what’s bringing down to Earth is trash. So you know there’s two types of spacecraft that go to space station, [uncrewed spacecraft and] those that have crews. And so they’re bringing the crew back, and there’s very limited room for bringing back piles. The majority of that trash is from the food, the food packaging and that type of stuff.

Going long distance, you want to minimise that. [Making] the packaging edible actually is one of the best things. You don’t want to have a whole bunch of stacks of Tupperware because volume is king. If you do have packaging, you want to make sure it’s very compact and stackable.

G: There’s actually science experiments and things on the station now to melt with plastic and make it into a little hockey puck, so you can just keep these hockey pucks. But they still get thrown in the spacecraft.

G: Now you start going to the Moon and Mars and stuff. Every week or so, you’ll put a bunch of things in the airlock and junk and throw it out in space.

Otherwise [it’s] going to be like living with a hoarder. You know, [the] magazines and the newspapers and everything will stack up around you.

R: If, as you said, most of the things brought back from space are trash, why aren’t they just put into the airlock?

G: Because of orbital dynamics, when you push something out of an airlock, unless it has a certain thrust and guidance, you don’t know when it’s going to come back and hit you in the back of the head.

G: If you were to stand in a in the centre of gravity of a spacecraft and take a pen when you’re orbiting around the Earth, [if you] give it a little push so it goes up, what will happen is it’s going into a higher and higher orbit now up meaning away from Earth.

G: So because it’s going higher and out in orbit, [it] will actually slow down because it’s transferring energy is becoming it’s increasing in in potential energy of the height off the ground, so it has to lose kinetic energy. So, it’ll actually go behind you. As you go around the Earth, it will actually come behind you, come up between your legs and you can catch it 90 minutes later, after you’ve done a [loop] of the Earth.

But now say you thrust a piece of trash out of the spacecraft, same thing. It goes around and then comes around. But now there’s all sorts of other forces on it with aerodynamic forces and sun pressure and everything else it may come back and hit you at 1000 miles an hour.

G: It could be pretty damaging, so you don’t want to just start throwing stuff out of the airlock because it doesn’t necessarily disappear. It will keep with you in orbit.

R: So, in Australian terms, everything is a boomerang in space?

G: Yeah, everything can be a boomerang in space. On the way to Mars, you might throw things out there, you [have to] push because you’re not in orbit, [if] you’ve given a little bit of pressure, then Newton’s laws [of motion] takes over. Anything in motion will stay in motion by the time you get to Mars.

R: I watched astronaut Chris Cassidy’s video on how to use the Waste and Hygiene Compartment from about two years ago. I think 2020 is the same year as Paragon’s STOOLE project got funding. With the STOOLE system, how is the processing of solid waste changing?

G: Well, there’s different toilets and I will tell you this, there is no astronaut that would say the toilet works. If you were maintaining your commode at home or and something went wrong with it every three weeks, you wouldn’t like it.

Your audience has to understand, the biggest issue with waste and space is there is no down. Every plumber will tell you it’s gravity that does the work. If you’ve installed plumbing, you have to have your waste lines. It’s so many inches per feet that it has to drop and then make sure that the flow goes in the right direction and all the other things. You don’t have any of that in space. So you have to push things to where they’re supposed to go.

G: Of course, it’s different with men and women. The plumbing is different and so collecting urine is pretty straightforward. The men, they have essentially a big thing looks like a condom, and you place yourself in it and you can pee. There’s always a little bit of suction or something. You don’t have gravity, so you’ve got to have a suction for pushing to get it away from you and into the bag.

Space Waste G: Like I say, the biggest problem we have with people who use these devices, and it’s not just astronauts; [it’s] people who do long distance like the U2 spy plane, it’s very often [a] 12-hour mission. You’re going to have to go to the bathroom sometime. The biggest problem we have with people like that is for men, is that the collection device comes in a few sizes, and they generally men always overestimate their size. There’s the saying, “Cut it to your length, not to your ego.”

G: Women are very different, you know, it’s essentially if you’ve ever seen what’s called a Pilot Buddy. You can buy them if you’re a pilot, it’s a shaped device that looks like a funnel that could be between her legs and get the urine to go in somewhere. Again though, you don’t have gravity, so there [has to be] some suction or some other device. Now the other side of the equation, this is tougher.

G: [Faeces] come out in any form. It can come out fairly solid. It can come out extremely liquid. if you have a sickness and stuff like that. Again though, the biggest problem is getting away from the body without messing. You know, there’s a reason why you wipe yourself. It’s because it’s not perfect.

G: The Apollo astronauts, they actually had a baggie and the Baggies were slightly different, was like your average sandwich bag, except there was a thumb bag. So when you put it on, it fit like a mitten with one thumb. Frankly, you could reach around and pinch it off yourself and pull it away. And then you pull the bag over.

No astronaut I’ve ever met from the Apollo era ever said “I’d love to have a poop in space”. Never. In fact, they tried very hard for the first seven [and] the last seven days before flight to minimise their solids intake so they didn’t have to go poop on the [way] to the moon and back.

G: The problem with faeces is storage. The STOOLE programme you mentioned was essentially getting that stool into a bag. Do you have a dog?

G: Dogs poop in the backyard; nothing’s worse than you go in the backyard and you find a fresh one. But if you look over, there’s one from three days ago and it’s dry and dehydrated. What you want to do is get rid of the moisture and recycle that moisture.

So what STOOLE did was it encapsulated, deodorised and then it allowed the water to be extracted back and made clean and put back into your drinking water and everything else, so that you ended up with a bag of very dry faeces.

G: We actually even played with having that 3D printed to make things for you later. through the wall.G: The most useful thing we found for it was actually the 3D print sheets or thin bricks, so you could put them on your spacecraft and minimise your radiation

G: I haven’t even mentioned and I don’t know the Australian culture, but women’s menstrual cycles are, you know, uniquely an issue in going to space.

Going to Mars, I got this question at the Space Tourism Conference or Space Settlement Conference Space Settlement Conference in in Seattle.

G: You’re a woman, you probably know how much you have to throw away every month. And you can’t do that. So you’re going to have to look at cups, but cups rely on gravity. The whole plumbing is actually very good at flushing things out, even in microgravity. That was the one of the concerns, one of the excuses for not having female astronauts. I think frankly, guys were just too nervous to deal with it, but.

G: We see it as a plumbing problem. It’s [just] different plumbing and the accommodations are different about it.

R: So I understand that with your doggie bag [comparison] that the solid waste is essentially dehydrated to extract water from faecal matter, but I wasn’t able to find much information on what happens to the solid waste itself. Is that still expected to bagged up and burnt up or is that expected to be utilised in a different way?

G: Yeah, I mean, I said that that most of the stuff coming back that comes gets burned up in the atmosphere is trash. One of the trash bags is full of poop bags and stuff like that. For the long duration, you can use it as a micronutrient for recycling. What you saw in The Martian, he had to open all the poop bags from, and he made a comment about somebody’s poop being smelling worse than somebody else’s. You know, there is a certain amount of that.

G: I will maintain that it’s very hard to recycle. You can’t really justify even going to Mars and back to recycle any of that. It’s a major part of the closure problem of what happens.

G: I have a chapter of a book coming out in early next year on what it would take to design a life support system to go to interstellar distances, go to the next star.

G: I say that your life support system will look a lot more like a brewery and a lot less like a farm.

G: Because when we get to the point of recycling faeces, most likely it will be put in bags, sort of like a wet compost pile. We have things called wet oxidisers that get rid of certain things. It’s essentially oxidising which is burning, but it’s doing it in a moist {environment].

G: What I also say in that book is, if we do grow anything going to the next planet, it will probably be things you can’t recycle, like spices.

Space Waste G:I think most of the growth of anything will be that, you know, peppers, spices, things like that.

G: The poop is an issue and what you do with it. Like I said, we found one of the most useful things usually is radiation protection. We worked on Inspiration Mars a few years ago and that made the national news. People were making the joke about putting baggies of poop on the wall to stop radiation.

R: Matt Damon’s character in The Martian uses poo as fertiliser for potato crops. So that’s not quite true?

G: Well, I mean you can. What he did, it’s called night soil in the in the farming world. And you can do that. There is no reason really why you can’t put poop in your own compost pile in the backyard. It would be a little smelly, I mean, we have a different poop than say like a ruminant, which is a like a cow. And the way they digest cellulose and stuff.

G: If you’ve done a compost pile, they say don’t throw in fatty things, don’t throw in bacon grease and all that type of stuff. Well, all that stuff’s in your poop and it takes a different microbial thing. Generally, human poop you want to [add] some anaerobic microbes to that they don’t need air. It’s much more odorous as it was implied in that movie.

R: Going on from the composting discussion, in 2015 NASA indicated that a potential deliverable of an ECLSS demonstration would be a clear application to Earth in pursuit of a more sort of sustainable planet. Water conservation is of particular interest to us because I’m not sure if you know, but SA is the driest state on the world’s driest inhabited continent. Do you think ECLSS has a potential for use at home?

G: Well I should say I live in Tucson, AZ, so I’ll battle you for who’s drier, you know.

G: There’s a bunch of things, NASA just supported a space food challenge. which was “How do you produce food in space?”

G: I was a judge for that for over 2 years. There was a surprising number of entries that were about microbial stuff and fungi and growing.

There is a boomlet now of continuous harvesting in a city setting in buildings.

G: Maybe you have a part of the of the of the city or somewhere where for economic reasons, there’s not any supermarkets. You can actually rent a building [like] a warehouse, put in a whole bunch of stacks of stuff and run it.

G: Food, water and stuff is so valuable in space, like our system that recycles 98% of the water out of urine on the Space Station. It costs almost, you know, $1000 per kilogram, which is never going to be viable for local use.

G: I’m from Iowa originally, which is a farming state. If you go there is just fields of beans and corn and you know it’s just efficient because you have the space.

But in certain parts of the world that’s not true. Being able to consolidate and miniaturise, that gives us more ways to do stuff.

I think NASA’s contributing part to that, not the only one, but a long part of it.

I will say going to doing food in space, one thing I can definitely see is that the microbial, the apps that you’ll use to make the basic food products, amino acids and so on. The only place that a 3D printer really makes sense in space is in food, so you can print a steak and then print a tomato.

G: I think the vast majority of the benefits are good of what we do, what NASA is trying to do, how it pushes the technology, how has it changed the thinking, I know that we’re working on a new space toilet. Again, nobody likes the space toilet, so it’s an opportunity.

I think my team has come up with some fairly innovative things that like I mentioned. Beginning in fact, my first challenge to them was, well, the toilet seat. I said “Hold it, why are we talking about a toilet seat? We don’t have gravity. You’re not sitting on anything, figure out another way to do it.”

G: We may come out with the ideal reusable diaper for a child, for all we know.

You never know, but you have to keep an eye out. Paragon has a very active intellectual property programme. .

R: You could really market that reusable children’s diaper by saying tested on astronauts, you know.

G: Yeah, yeah, that might do. If we can hold an astronaut, it’ll hold your child.

I’ve raised three kids, and I can tell you, they will come out with things that the just the diaper will not hold. That’s part of the fun again of having to design around, you have to design for all physical capabilities.

The Waste and Hygiene Compartment uses suction to get waste away from the astronauts and processed through the closed-loop ECLSS, without the use of gravity or water.

You may be surprised to learn that waterless toilets aren’t just for space missions though. For some, they’re a current daily reality.

back down on earth...

For those who attended our Roadshows, you might have heard the Office of the Technical Regulator talk about waterless composting toilets with urine diverters. By definition, waterless toilets or ‘dry sanitation’ systems do not use water to treat or transport human waste.

As well as reducing water use, waterless toilets can keep pollutants out of waterways. According to the Department of Climate Change, Energy, the Environment and Water, they are particularly appropriate for rural settings, but can be used anywhere, depending on local government regulations.

Joshua Knight from the Office of the Technical Regulator has verified “Yes, as the everyday consumer is looking to do their bit for the environment, we have had increased enquires into the use of waterless composting toilets with urine diverters. Diverting the urine helps to increase the capacity of a composting toilet and can help reduce issues with odour.”

SA Water has approved a number of waterless composting toilets, with AS/NZS 1546.2 Certification. However, under the Wastewater Regulations in South Australia, all composting toilets are the subject of product approval by SA Health.

If you were planning on acting out The Martian’s potato growing scene, your dreams may be on hold: The Department of Climate Change, Energy, the Environment and Water has stated that the compost from composting toilets should not be used to grow vegetables.

Joshua Knight from the Office of the Technical Regulator has also said “Currently there is no compliant way to connect a urine diverting toilet to a Sanitary drainage system. They are also not WaterMark approved, so please confirm with your local council environmental health officer before installing.”

It is important to note, it’s legal to sell non-WaterMark certified plumbing and drainage products in Australia. But if the product type is listed on the Schedule of Products but is not WaterMark certified, a licensed plumber is not permitted to install it.

The question remains: Whether it’s in outer space or South Australia, who knows what the future of plumbing will bring?