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Arthur T Knackerbracket has found the following story:
You may've heard that astronauts on the International Space Station recycle their own pee into drinking water, but space travelers could also one day upcycle their own urine into tools and other useful items.
Researchers from Clemson University are exploring ways that strains of yeast can be used to convert nitrogen from urine and carbon dioxide from astronauts' breath (or perhaps the atmosphere of Mars) into useful substances like nutrients or polymers. One strain of engineered yeast creates polyester polymers that could be used in 3D printers to create needed tools or parts for a long space mission.
The researchers presented their work Tuesday at the 254th National Meeting & Exposition of the American Chemical Society (ACS) in Washington.
[...] Having "a biological system that astronauts can awaken from a dormant state" and start using to produce what they need, when they need it, is the project's motivation, Blenner said.
See also: EurekAlert.
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(Score: 2) by theluggage on Sunday August 27 2017, @05:52PM (4 children)
Ever seen a tree?
Yes, ultimately the mass comes from the food that they take with them, but they need to scrub the CO2 from the air and urea from urine (to recycle the water) anyway so why not look into ways of using it rather than spacing it? Especially if the "equipment" is a pinch of dried yeast, and even more so if they have an unlimited CO2 source (as they would on Mars).
The only question is whether CO2 and nitrogen would be better used growing plants for food.
(Score: 2) by vux984 on Sunday August 27 2017, @08:57PM
Well put!
(Score: 2) by ledow on Monday August 28 2017, @11:29AM (2 children)
You mean those things that take hundreds of years to grow, enormous resources from the soil, literally tons of water, huge amounts of solar power, and then produce a few lengths of timber for all that effort? (Oh, and a functioning ecosystem of fungi, soil bugs, insects, pollinators, mosses and all sorts of other things)
Exactly my point.
If they were that efficient, we wouldn't be worried about destruction of the rainforest, we'd just plant trees all over and come back next year.
Trees are only efficient on geological timescales, we just don't have that kind of time in space. In the time it takes even the smallest tree to mature, we could have synthesised almost anything from almost any other source, using much less energy. Technically, if you extrapolate enough, your answer also applies to oil. That's just sunlight and air crushed for a few million years. This is also one of the reasons we are trying to cut back on using that stuff. It's incredibly convenient - if it's been growing for thousands of years - and we can cut it down back to bare soil in only a few hundred. It doesn't mean it's sustainable.
Most of that trees survival is also based on seriously nutrient-rich soil and water. Not air.
(Score: 2) by theluggage on Monday August 28 2017, @12:48PM (1 child)
Tell that to the bloody leylandii that completely overran my garden and blocked the sun when I turned your back on for a few years. Or the the fast-growing conifers that they plant for "sustainable*" paper and cheap furniture. Or the scrubby stuff they can plant and harvest to burn for carbon-neutral* energy. Or old techniques such as pollarding [wikipedia.org] that have been used since forever to get regular crops of wood products.
All Giant Sequoias are trees. All trees are not Giant Sequoias.
...the sort of nutrients that only make up a fraction of the tree's mass, and which are replenished by the action of bacteria, fungi etc. on dead foliage and animal waste (sound familiar?) Exactly the sort of processes you need to study (and improve) if you want to build a long-term sustainable space habitat (of course, no closed system is going to be infinitely sustainable . planets only get past that on scale - but copious solar energy helps buy off the second law of thermodynamics for a while, and you have to aim to do better than depending entirely on having bought along everything you'll ever need ready-made).
(* to avoid arguments, let's acknowledge that "sustainable" and "carbon neutral" claims also depend on rather complicated and confirmation-bias-prone full-lifecycle analyses, including whatever you ploughed up to build your sustainable biomass farm, and how much oil you burned doing that)
(Score: 2) by ledow on Wednesday September 06 2017, @10:16AM
The mass of the leylandii grown would be no less than the mass of the fertilizer present, the nutrients removed from the soil, and amount of gases consumed.
Literally, you would have to have JUST AS MUCH MASS AS THE TOOL YOU WANT. Plus more. Sometimes as much as 3 times more mass in soil than the tree/plant itself in order to support it. The amount of gas - over a decade or so - is a lot, but it's operating 24 hours a day in an environment with tons of that gas produced. Your astronaut are putting out grams-per-day. Even 100% efficient conversion means your tools won't be ready for a few months each, probably years. And most of that mass would actually be wasted / expended in things you CAN'T use as tools. And much more of that mass would come from the supporting functions, which all need the same resources to feed from.
It's a zero-sum game. The mass added to the system has to equal the mass removed (i.e. the mass of the tool), plus a bit more for losses/conversions/unused gases/support structures/etc. or you end up depleting things rather quickly.
You are enclosed and we're assuming you can't use the local resources (i.e. no fertile soil just laying around, wrong kind of atmosphere, etc.). Talking about using people's breath is pointless. It would literally be lost in the noise of the rest of the infrastructure to sustain it, let alone start it.
You can ship: trees, bacteria, fungi, soil, etc. etc. etc. and use a pittance of gas that you collect alongside the mass of gas that you need... to create a small tool. Or you could just send a tool. Over time, everything you ship will deteriorate and need replenishing (I don't know how much fertilizer / water a tree would need, even genetically engineered to grow into a perfect flat bit of wood with no waste, but it's not trivial and not less than the mass of the tool you want to make from it. In an enclosed area, it will need a lot more than it would in a massive planet-sized self-sustaining eco-system.
It's literally just down to mass. Everything you ship to make a self-sustaining system has come from somewhere. The fungi consumes mass itself and may contribute a vital element, but it's not self-sustaining either.
If the mass required has come at cost from Earth, it's almost immediately a loss-maker unless it's directly usable. And these things are only self-sustaining in huge bulk, not small colonies. Literally shipping forests.
It's a nonsense to suggest that we can grow tools, and do so profitably, when most gardens weigh more than entire space payloads like Apollo I (20 tonnes). That's just 12 cubic metres of soil. "It has been estimated that 300 to 400 cubic feet of soil is required to support a medium-sized shade tree" - i.e. you'd need to lose 20 tonnes of payload to grow one tree in Earth conditions, let alone all the stuff that's required in a hostile-to-life environment like space/other planets. Are you going to get 20 tonnes of tools out of it? Are you going to have to water it with hundreds of tons of water? Are you going to be able to sustain it in less than 20 tonnes of support equipment, etc.?
It's a nonsense. And it's a nonsense just by sheer mass alone. Even without working out how much fuel you'd need to lift off that much mass in the first place / maneouvure it even between "space ports" or safely land and use it.