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67

Right now, almost 100% of existing research on growth in gravity fields is basically at 0g (ISS/Mir/Skylab/whatever) or 1g. There are a lot of questions of what happens at 1/6g or 2/3g? No good experiments to demonstrate. Thus the Chinese lander is testing 1/6th g. SpaceX is likely to brute force test 38% g when they get to Mars. It is entirely possible ...


22

Some of the rocks on Mars aren't too bad for growth of plants or bacteria. They contain a considerable amount of clay minerals (about 20%), and several other minerals which are considered as essential and sufficient for bacteria to survive, at least. Probable chlorinated salts, e.g. perchlorates, which are likely and wide-spread in Martian soil, don't ...


17

The higher plants are less efficient, so the entity will probably be not a bush, but a jar of algae. 30-40 liters of Сhlorella suspension could provide for a gaseous exchange of a single person. Grishin Yu. I. "Artificial Space Ecosystems" Cosmonautics, Astronomy 7/1989


17

So far the studies that have been performed in orbit have shown that plants grow perfectly normal (shoots up, roots down--so to speak) in microgravity. They also produce healthy offspring which can grow new plants in orbit. Experiments have been performed on Arabidopsis and other Brassicaceae. Aboard the ISS a special “plant growth chamber” called Advanced ...


16

This is a remarkably interesting exchange. I would like to add a few concerns (as an engineer, I go straight for the problems)... Full culm bamboo is a remarkably inefficient product to transport and thus any use in space would require bamboo to be grown in space. On Earth, we consider bamboo inefficient if it is not grown within about 200 km of its end use....


15

This article addresses much the same question. The quick summary is about 300 to 500 typical domestic houseplants per person, with significant caveats, more like 700 to be safe. So 6-14 thousand such plants for 20 people. Another approach based on some data from other answers on this site is to observe that the net amount of oxygen produced by a plant is ...


14

Plants don't just need carbon dioxide; like most organisms, they need oxygen to survive as well. They can produce oxygen from carbon dioxide, but that doesn't help cells that aren't exposed to sunlight; if you put a plant in a very low-oxygen environment, it will die. There are organisms that can survive on little to no oxygen (e.g. cyanobacteria, which can ...


14

There are certain plants that are more efficient in removing and adding Oxygen to the surrounding environment, but the main disadvantage is that they need soil with comfortable acidity otherwise the roots of the plants would die. That prevents them from being used on other planets where the acidic contents in the soil is more (but there are a few exceptions)....


13

It depends on your definition of exploration missions. Talking about human space flight into low Earth orbit, yes, there have been plenty of plants and successful experiments involving growing plants in space. Some are still going on on-board the ISS. Astronauts also, intentionally or unintentionally, let stuff grow which is actually part of their food ...


12

How different are Mars soil from Earth's soil? Mars has no soil. Soil has an organic component, which (so far as we know) is lacking in Mars regolith. Actually, the Viking probes may have found signs of organic compounds in the Martian soil, but even until today the results of the experiment are in dispute. Interestingly all Martian landers since, with the ...


12

Mars' atmosphere scale height is, depending on who you ask, 10.8 to 11.1 km. Pressure at the bottom of Hellas Planitia: 1.16 kPa Earth sea level: 101.3 kPa Earth 6km altitude: ~50 kPa. So we need air pressure to increase by a factor of about 43; ln 43 = 3.76 scale heights -- so we need a trench about 41km deep. Start digging! This gets equivalent air ...


11

We don't really know. A study from 2012 suggests that lichens and cyanobacteria could indeed survive the "obvious" perils of Mars, including radiation, low pressure, and temperatures dropping as low as $-50°\text{C}$. In 2012 the Planetary Society reports a two-stage experiment performed at the German Aerospace Center, in which (1) organisms were ...


10

All life as we know it requires liquid water as a medium (a polar solvent) in which the chemistry of life can take place. Mars surface conditions pretty much preclude the existence of liquid water. The atmospheric pressure is at or below the triple point of water, meaning that water can only exist as ice or gas (vapor). Even though Martian soil probably ...


10

They did it for propaganda or pride mostly. What sprouted quickly died because it froze. They did not have a method to protect the biosphere from the temperature swings. This is what they expected and admit. The Chang'e-4 probe entered a "sleep mode" on Sunday as the first lunar night after the probe's landing fell. The temperature could drop as ...


10

Perchlorate contamination is a problem on Earth. Essentially, there is a series of water treatments and bioremediation, the process of using biological systems to fix the problem. Here is a detailed summary of one effective approach. The short answer is this: Engineers know how to do this on Earth, and the Martian solution is likely to be an adaptation of ...


9

Despite the fact that on Earth, Nitrogen is the most abundant element in the atmosphere, plants do not get their nitrogen from the air - it is just too hard to get it. A plant would need to expend lots of energy to break the N2 bonds. Instead, they get all their nitrogen from the soil, where bacteria in the soil have already converted N2 to NH3 (nitrogen ...


9

Generally, without any external disturbance, cohesive forces of the materials in use will be sufficient to keep them together, since they all share the same inertial frame. But sure, to prevent soils from scattering around when moved around, worked with or perhaps due to air circulation, they can be contained in growing pots or similar containers that would ...


8

Looking at the information on what plants were taken in to space, it appears that the criteria include: Size: initially small plants were taken. This makes sense from a weight perspective Well studied: the list of plants aligns well with those studied extensively in universities. Again, this makes sense - it may be easier to identify odd growth in a well ...


7

Life may once have existed on Mars, which is largely why so much exploration of it is being done now. There is evidence of flowing water, which implies a warmer climate and thicker atmosphere. But that atmosphere was stripped away as the sun grew hotter, and now Mars is frozen. It doesn't have enough gravity or a magnetic field strong enough to hold in an ...


7

In addition to the gravity, an important influence for plant growth is light (cf. Photoperiodism). So, in microgravity plants still "know" which direction to grow - leafs towards the light (for Photosynthesis), roots away from it, towards water/nutrients. As others pointed out, space experiments confirm that plants do grow in microgravity.


7

The announcement was first made by the vice principle of Chongqing University (the primary designer of the growth module) on the 15th of January and you can find the original article summary from their university website here (in Chinese of course). The first image is from the lunar module (the actual time the photo was taken was 7th January around 10am). ...


6

From "The Case for Mars", using Viking data, it can be shown that the soil is similar, although we don't know about the nitrogen content. Iron in particular is higher, Potassium is lower. They also contain smectite clays. Bottom line is, there are probably parts of Mars that have enough minerals to grow plants, and those things that are lacking could ...


6

Plants produce oxygen by photosynthesis, where they convert light and CO2 into sugars which they can use to grow. Luckly for us, the oxygen is a waste stream which we can use. $${{6\ CO_{2}+6H_{2}O+energy\longrightarrow C_{6}H_{{12}}O_{6}+6\ O_{2}}}$$ This process requires light, so the amount of light the plants are able to receive is an important factor. ...


6

Yes. While Mars only receives about half of the light that Earth does, it doesn't have clouds or other similar items to deal with. Assuming you can have a dome that is very clear, you should have about 600 W/m^2, while the surface of Earth has 1000 w/m^2 (source). The site linked to has some great pictures, I'm not sure if I can use them here. Assuming ...


6

Apart from perchlorate treatment mentioned in @Chris's answer, there are some other methods which could be able to remove the perchlorate from the martian soil: Rinsing the soil with water. Perchlorate dissolves in water. Heating the soil. Perchlorate decomposes giving oxygen as byproduct. Using perchlorate eating bacteria which produce oxygen as a ...


5

Roughly speaking Mars gets between 1/2 and 1/3 the light that Earth gets (depending on time of year) meaning you could probably grow plans that handle full shade on earth pretty well but most crop plants are more on the full sun side of things. Growing crop plants would probably require concentrated light if you were going to use natural light. LED grow ...


5

Allow me to give the obvious answer of spirulina. Here's a NASA report from 1988 on the subject of growing food during space missions. I don't know if it's particularly different from any other NASA report on the subject: http://ntrs.nasa.gov/search.jsp?R=19890016190 The abstract is unhelpful, but the entire introduction is highly relevant to your question,...


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