This is cool. I look forward to seeing the results of this experiment. In case you were curious, this is routinely done on the ISS [1] so I don't expect low-g on the Moon to be an issue. The one issue is radiation (which is mentioned) because the Moon is exposed to this in a way the ISS isn't (thanks to the Van Allen belt).
Should this become necessary however, it won't even be an issue long-term. Why? Because you'd grow things underground. There's absolutely no reason to do anything above ground on the Moon. We have pretty strong evidence of ancient lava tubes so there's no need to excavate either.
Ideally, you'd seal a lava tube and put in air and you could live in it with the plants being natural oxygenators.
Long-term you'd probably want to see if you could manufacture growth medium on the Moon from available materials.
From the article, I believe the effects of the radiation are what's being tested. Which is an important thing to know if we want to put people on Mars as it also has a huge amount of radiation and food is heavy to transport.
If we can grow plants above ground, that can free up resources for an underground colony.
> Why? Because you'd grow things underground. There's absolutely no reason to do anything above ground on the Moon
If you grow stuff on the surface and in the sun (with some imaginary window that let the good parts of the sun rays go through, without any of the bad stuff through), wouldn't that be at least slightly more energy efficient, compared to growing stuff underground with lots of strong lights?
The problem with the Moon is the 28 Earth day day/night cycle. It takes the Moon from blistering heat (~250F) to bone-chilling cold (-200F) so anything on the surface has both a cooling problem and a heating problem.
There's no atmosphere so the only way to get rid of heat is to irradiate it away into space or pump it away and do the same thing. Likewise, heating is a big problem and an energy waster as you're irradiating away heat.
Going underground just avoids the heating problem, the cooling problem and the radiation problem. It also avoids the issue of meteor impacts on the surface. Those craters came from somewhere.
Excavation is expensive but it depends on what you're working with. Is it loose? is it hard rock? I don't think we have good knowledge of the geology of the Moon because we'd have to go there and start drilling cores to find out. The presence of ancient lava probably means we'd be dealing with some hard stones too like basalt or granite. But that's just a guess.
Lava tubes, if sufficiently large, just solve so many of these problems.
It's just easier to collect power and produce the light you want to grow somethin gunderground.
Living on the moon works, because we can send supplies frequently like we do with the ISS. Meanwhile mars is so far away that anyone who goes there signs up for a suicide mission.
Every single mars mission proposed by musk relies on a pyramid scheme where every round of launches sends more and more people until one day self sufficiency is achieved and the first guy sent to mars will have a chance of returning to earth.
Here's a fun youtube video on just how much it'd take to survive on plant life alone. [1]
Spoilers: Can't be done without a huge amount of vegetation. Algae, on the other hand, can work, but it still takes a boat load of algae for just 1 person.
> Ideally, you'd seal a lava tube and put in air and you could live in it with the plants being natural oxygenators.
There's a LOT of oxygen on the Moon (basically in every rock). There's effectively no carbon. If you want to grow plants there - you need to take carbon with you (probably in the form of coal you'll burn once there to generate the CO2 needed for plants).
1 person eats about 1000 kg of food per year, which is about 500 kg of carbon. If you grow plants in a yearly cycle you need to sent half a ton of coal for every colonist. The ones born on the Moon too.
This sounds very off. Dried rice is 400 kcal per 100g. That is 500g of uncooked rice per day or 180kg of uncooked rice. What you are counting as "food" is the cooking water being absorbed into it.
Those humans are also producing CO2 so it will have some self-sustainability. The 5% CO2 of human breath is a lot more than the ~0.04% in the atmosphere.
I have no idea how to calculate the steady state or what the losses would be.
Is the radiation close to normal light on earth, so that maybe fiber glass tubes could be used to route the light in a controlled manner into underground caves?
Too bad they are going to remain on the surface. Maybe next time they will set up all the hydroponics in a lunar cave. There are shaded areas in craters that supposedly remain a constant 63F (17C) year round.
If the soil has no nutrient capacity, there's no reason to use it. Hydroponics work well enough. I just don't see the case for immersing roots in a medium, where the question is whether the medium would be quite toxic enough to kill them entirely, when roots can grow in air.
Certainly, apart from light and water and gasses, plants may require certain physical soil properties and nutrients, and possibly other lifeforms to thrive.
Besides elements that should be present, there are elements that should rather be absent; you don't want to grow potatoes in a soil rich in arsenic or lead.
IIRC, most analyzed samples of Moon regolith contain something that plants don't exactly like, but can tolerate. Some selection and / or genetic engineering may be required to produce plants that grow readily on regolith-based soils.
This is not correct. Most plants get their N from nitrates or ammonia salts, and only some plants (mostly leguminous ones) use a direct symbiosis with nitrogen-fixing bacteria to produce these from atmospheric N2. Most of the N in natural ecosystems comes from decay of proteins (from vegetable or animal origin), and in agriculture of course it is added as fertilizer.
Depends where in space. From the article: "the International Space Station orbits within the Earth’s magnetic field, and so it is exposed to much lower radiation levels than the lunar surface".
Plant roots don’t need gravity to draw water! Plants use evaporation and the tensile strength of water (yes, really!) to draw water up against gravity.
When people think of radiation protection, they think of the magnetosphere. But they really need to be thinking of the atmosphere. There's a reason traveling on a plane gets you a higher dose of radiation and it's not a weaker magnetosphere.
Perhaps a thick shell of water suffices. In the order of meters, perhaps one to four meters. Perhaps combine it with lead, in the order of centimeters, perhaps ten centimeters, then one meter of water would suffice.
There will never, ever be such atmosphere on Moon as its on Earth. Too low gravity for example, solar winds would scrub it pretty fast even if you would somehow create it 100% with a snap of fingers.
Its nice dreaming about options but this aint realistic.
There doesn't seem to be any single food that is alone nutritionally complete, but potatoes are certainly one of the closest... many people seem to do well with just potatoes for a month or two. A few supplements (B12, etc.) would likely allow potatoes to work long term.
Readit News
Should this become necessary however, it won't even be an issue long-term. Why? Because you'd grow things underground. There's absolutely no reason to do anything above ground on the Moon. We have pretty strong evidence of ancient lava tubes so there's no need to excavate either.
Ideally, you'd seal a lava tube and put in air and you could live in it with the plants being natural oxygenators.
Long-term you'd probably want to see if you could manufacture growth medium on the Moon from available materials.
[1]: https://gardenculturemagazine.com/growing-hydroponics-in-spa...
If we can grow plants above ground, that can free up resources for an underground colony.
If you grow stuff on the surface and in the sun (with some imaginary window that let the good parts of the sun rays go through, without any of the bad stuff through), wouldn't that be at least slightly more energy efficient, compared to growing stuff underground with lots of strong lights?
There's no atmosphere so the only way to get rid of heat is to irradiate it away into space or pump it away and do the same thing. Likewise, heating is a big problem and an energy waster as you're irradiating away heat.
Going underground just avoids the heating problem, the cooling problem and the radiation problem. It also avoids the issue of meteor impacts on the surface. Those craters came from somewhere.
Excavation is expensive but it depends on what you're working with. Is it loose? is it hard rock? I don't think we have good knowledge of the geology of the Moon because we'd have to go there and start drilling cores to find out. The presence of ancient lava probably means we'd be dealing with some hard stones too like basalt or granite. But that's just a guess.
Lava tubes, if sufficiently large, just solve so many of these problems.
It's just easier to collect power and produce the light you want to grow somethin gunderground.
Is there a reason to do anything below ground? We already aren't doing anything above ground.
Underground just requires LEDs and solar panels. Both of which we can make quite cheaply.
We've tried that on earth and it doesn't really work. You need a lot of plants and a wide variety of plants.
Living on the moon is a fantasy. It won't happen in any of our lifetimes. Mars is an even greater fantasy.
Every single mars mission proposed by musk relies on a pyramid scheme where every round of launches sends more and more people until one day self sufficiency is achieved and the first guy sent to mars will have a chance of returning to earth.
Spoilers: Can't be done without a huge amount of vegetation. Algae, on the other hand, can work, but it still takes a boat load of algae for just 1 person.
[1] https://www.youtube.com/watch?v=xWRkzvcb9FQ
There's a LOT of oxygen on the Moon (basically in every rock). There's effectively no carbon. If you want to grow plants there - you need to take carbon with you (probably in the form of coal you'll burn once there to generate the CO2 needed for plants).
1 person eats about 1000 kg of food per year, which is about 500 kg of carbon. If you grow plants in a yearly cycle you need to sent half a ton of coal for every colonist. The ones born on the Moon too.
I have no idea how to calculate the steady state or what the losses would be.
Is the radiation close to normal light on earth, so that maybe fiber glass tubes could be used to route the light in a controlled manner into underground caves?
https://en.wikipedia.org/wiki/Aeroponics
TIL
IIRC, most analyzed samples of Moon regolith contain something that plants don't exactly like, but can tolerate. Some selection and / or genetic engineering may be required to produce plants that grow readily on regolith-based soils.
They certainly require other lifeforms. The vast majority of plants depend on microbes for nitrogen fixation.
> Growing plants on the ISS is a complex business, and Porterfield says a chief concern is that plant roots depend on gravity to draw water.
So while the radiation might be similar (I'm not sure), other variables are different.
Its nice dreaming about options but this aint realistic.
Deleted Comment
Deleted Comment