How far are we from developing fully self-sufficient space stations? originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights.
Answer by Robert Walker, Writer of articles on Mars and Space issues, on Quora.
We are a long way away from developing fully self-sufficient space stations. At least if you mean ones that are able to make and repair all the complex machinery, spacesuits, life support systems, computers, modules, etc.
Instead, what they are attempting is:
They are not attempting to make complex things like a spacesuit in space.
A spacesuit would cost around $2 million dollars to build from scratch (not including design costs). It would take someone who had all the necessary skills about two and a half years to build, given a supply of all the parts and materials needed. See Space suit evolution (NASA).
That's on the Earth with all our facilities. So, it is not likely that we can build them in space with 3D printers at present or in the near future.
Given those limited aims, they are making some progress. So far the ISS hasn't yet reached step 1, recycling all its oxygen. However, that is their aim for the next generation of life support systems, to generate a higher and higher percentage of their oxygen through recycling it.
Then some experiments on the Earth have got close to achieving the second aim - to grow much of their own food (BIOS-3 in Russia, also some in the US ). But these results have not yet been duplicated in the more challenging conditions in space.
These experiments used aeroponics (plants with their roots growing in air saturated with water vapour) and hydroponics (with their roots growing in water). In the BIOS-3 experiments, using multiple croppings of dwarf wheat, radishes, beet etc, they got the main bulk of their food from just 13 square meters of growing area per person.
Another way to grow most of their own food is to follow the MELiSSA approach. The main difference is that the BIOS-3 system burns plant wastes in an oven, while MELiSSA relies extensively on high tech "composting" basically - lots of microbes. They are already doing tests on the ISS of microbes that could generate oxygen from algae.
So, 1 and 2 eem feasible - but it is probably still a decade or two before we get to the point where you can grow most of your food actually in space.
For 3, they hope to be able to print out copies of some replacement parts in the future, which could be useful if a vital piece of equipment fails on a long journey. But they don't aim to make everything that way. Certainly not the spacesuits and the electronics and all the complex materials.
Then as well as that, we haven't yet been able to build a permanent space station. Instead every single module we've sent into space gets destroyed in the atmosphere within a few decades.
That's not because we can't keep them up there. Even when we can, as with the ISS, they have finite and rather short lifetimes. We still can't built modules that will last longer than a few decades in space. While on the ground houses can last for centuries. They need maintenance, but don't have to be completely destroyed and remade every few decades.
Space modules are of course far far harder to construct than ordinary houses. I don't know if it will be possible to build them in space, but if so this is a long way away yet. First we need to learn how to build long lasting habitats with all the facilities we have on Earth, ones that don't need to be replaced every few decades.
The idea of self sufficient space colonies that could make everything in space, including those expensive and complex spacesuits - and cooling s
Answer by Robert Walker, Writer of articles on Mars and Space issues, on Quora.
We are a long way away from developing fully self-sufficient space stations. At least if you mean ones that are able to make and repair all the complex machinery, spacesuits, life support systems, computers, modules, etc.
Instead, what they are attempting is:
- First, to recycle all the oxygen for breathing. At the moment they lose a lot of it into space as carbon monoxide or carbon dioxide. In the future, they could convert those gases to methane before they vent it, and so lose only carbon and hydrogen; saving the oxygen for recycling.
- Then, they could make all their food as well, using the recycled CO2 to grow plants or microbes.
- Use 3D printers to make some of the replacement parts.
They are not attempting to make complex things like a spacesuit in space.
A spacesuit would cost around $2 million dollars to build from scratch (not including design costs). It would take someone who had all the necessary skills about two and a half years to build, given a supply of all the parts and materials needed. See Space suit evolution (NASA).
That's on the Earth with all our facilities. So, it is not likely that we can build them in space with 3D printers at present or in the near future.
Given those limited aims, they are making some progress. So far the ISS hasn't yet reached step 1, recycling all its oxygen. However, that is their aim for the next generation of life support systems, to generate a higher and higher percentage of their oxygen through recycling it.
Then some experiments on the Earth have got close to achieving the second aim - to grow much of their own food (BIOS-3 in Russia, also some in the US ). But these results have not yet been duplicated in the more challenging conditions in space.
These experiments used aeroponics (plants with their roots growing in air saturated with water vapour) and hydroponics (with their roots growing in water). In the BIOS-3 experiments, using multiple croppings of dwarf wheat, radishes, beet etc, they got the main bulk of their food from just 13 square meters of growing area per person.
Another way to grow most of their own food is to follow the MELiSSA approach. The main difference is that the BIOS-3 system burns plant wastes in an oven, while MELiSSA relies extensively on high tech "composting" basically - lots of microbes. They are already doing tests on the ISS of microbes that could generate oxygen from algae.
So, 1 and 2 eem feasible - but it is probably still a decade or two before we get to the point where you can grow most of your food actually in space.
For 3, they hope to be able to print out copies of some replacement parts in the future, which could be useful if a vital piece of equipment fails on a long journey. But they don't aim to make everything that way. Certainly not the spacesuits and the electronics and all the complex materials.
Then as well as that, we haven't yet been able to build a permanent space station. Instead every single module we've sent into space gets destroyed in the atmosphere within a few decades.
That's not because we can't keep them up there. Even when we can, as with the ISS, they have finite and rather short lifetimes. We still can't built modules that will last longer than a few decades in space. While on the ground houses can last for centuries. They need maintenance, but don't have to be completely destroyed and remade every few decades.
Space modules are of course far far harder to construct than ordinary houses. I don't know if it will be possible to build them in space, but if so this is a long way away yet. First we need to learn how to build long lasting habitats with all the facilities we have on Earth, ones that don't need to be replaced every few decades.
The idea of self sufficient space colonies that could make everything in space, including those expensive and complex spacesuits - and cooling s