Certainly, apart from light and water and gasses, plants may require certain physical soil properties and nutrients, and possibly other lifeforms to thrive.
A small centrifuge won't work; you get a strong coriolis effect. A large centrifuge could, but the ISS doesn't have one of those. It would need to be huge to be absolutely sure your data is accurate.
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.
While that is true, plant roots and stems use gravity to know in which direction to grow (roots down and stems up), so that will cause problems in space.
NASA has succeeded to grow some plants on the ISS, by making them grow towards a source of light (i.e. LEDs), but until now this has worked only for some very low-growing plants, like lettuce and some varieties of cabbage, not for plants with deep roots and high stems.
It should be much easier to grow algae in the absence of gravity, but those are not as tasty as terrestrial plants.
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.
We are only talking about "fast" relative to normal planetary timescales.
My understanding is that it would still take hundreds of years for the solar wind to strip away the atmosphere. If a civilisation had the technology to quickly put an atmosphere on the moon, it has the technology to continually replenish the atmosphere as long as that civilisation lasts.
It would never be practical (or a good idea) but a post-scarcity society could pull it off as a vanity project.
You don't absolutely need to put your base somewhere it'll have a night. There's a large mountain chain on Moon's south pole that's in constant sunlight.
Maybe there's a joke here that I'm not aware of, but my question was mostly why they think dairy is necessary. I do believe that potatoes isn't enough, but you don't need dairy products.
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.
I thought there are some regions in the North Pole that are constantly illuminated. Presumably the temperature is significantly more stable in those regions.
That's not a reason to do something below ground on the moon. It would be a reason not to do something above ground, which, as I noted, we already don't do.
I've moved beyond not doing things on the moon. That's so passé. I'm already not doing things above ground (or below ground on Mars) and have no plans for the moons of Venus after that.
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.
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?
> 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.
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.
I find it interesting that he thinks being nuked every two years is a benefit to being so far from an out of control Earth. I’ve seen BSG and know nukes can fly in space.
He also baked in an out for himself. Now, if Kamala Harris wins the Presidency, he can say that she prevented from totally doing the thing he said he was going to do.
5 unmanned mission in the 2026 launch window, manned mission to follow in 2028 if the unmanned are successful is the most recent statement (though some reports garbled that into all 6 happening by 2026.)
I'm not saying 5 successful unmanned missions are impossible in 2 years, but I think Elon may have slightly underestimated the difficulty of the task. There is a lot of stuff left to develop still and very little time to do it.
Elon is not great at estimating how long tasks will take. He originally promised that full self driving would be complete by 2018.
Note that its not so much five in two years as five in a narrow window that opens in two years; they’d be near-simultaneous missions, on whose success would depend the manned mission when the subsequent launch window opened.
But, yeah, Musk timelines are not something I would put a lot of faith in.
Vastly under-estimating the magnitude of the task is how the crazy things get done.
Christopher Columbus wasn't unique in believing the world was round, he was rather unique in his vast under-estimation of the distance to Asia. The only reason he survived is dumb luck that the Americas were about where he thought Asia was. All of his doubters were correct that he would die before reaching Asia.
Of course, this way, way far down the list of reasons not to take Christopher Columbus as a role model.
Certainly, apart from light and water and gasses, plants may require certain physical soil properties and nutrients, and possibly other lifeforms to thrive.
Is the radiation not similar to the one you get in space? seems like that would be a cheaper place to test the effects of radiation.
They're also testing the effects of reduced gravity.
from the article:
> 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.
I’m sure they have considered this and/or doing it already but you’d only need a small centrifuge to simulate gravity for an experiment.
A small centrifuge won't work; you get a strong coriolis effect. A large centrifuge could, but the ISS doesn't have one of those. It would need to be huge to be absolutely sure your data is accurate.
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.
While that is true, plant roots and stems use gravity to know in which direction to grow (roots down and stems up), so that will cause problems in space.
NASA has succeeded to grow some plants on the ISS, by making them grow towards a source of light (i.e. LEDs), but until now this has worked only for some very low-growing plants, like lettuce and some varieties of cabbage, not for plants with deep roots and high stems.
It should be much easier to grow algae in the absence of gravity, but those are not as tasty as terrestrial plants.
How much energy would be required to provide a localized magnetosphere to protect the garden from cosmic rays?
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.
Cover your garden with a few dozen meters of rock. In fact, build your base in a cave.
We are only talking about "fast" relative to normal planetary timescales.
My understanding is that it would still take hundreds of years for the solar wind to strip away the atmosphere. If a civilisation had the technology to quickly put an atmosphere on the moon, it has the technology to continually replenish the atmosphere as long as that civilisation lasts.
It would never be practical (or a good idea) but a post-scarcity society could pull it off as a vanity project.
How tolerant are plants to cosmic rays?
This is what the test covered in the article is set to discover.
Seems like solar could easily supply?
Easily, assuming you have solar panels that could survive the temperatures of the lunar night.
You don't absolutely need to put your base somewhere it'll have a night. There's a large mountain chain on Moon's south pole that's in constant sunlight.
Plants grow in radioactive soil around Chernobyl just fine though.
Those radiation liking mushrooms could be an interesting test for the next batch of plants to the moon. :)
All we need is a bunch of potatoes, but don't figure to have a healthy stock of ketchup on board.
BizarroLand wins the award for getting the joke (reference to the movie "The Martian"). Please forgive my taste for very nuanced humor. :-)
Potatoes aren't enough by themselves, you need dairy to hit all the nutritional requirements.
you still haven't properly implemented nachos.
Why do you think so?
https://www.snopes.com/fact-check/potato-butter-diet/
Could keep you alive long enough but eventually you'd want some other nutrients.
Maybe there's a joke here that I'm not aware of, but my question was mostly why they think dairy is necessary. I do believe that potatoes isn't enough, but you don't need dairy products.
> you don't need dairy products.
You generally need animal products for B12, but you can use supplements, I think. B12 deficiency can take a year or more to manifest severe symptoms.
In the movie "The Martian" Matt Damon grew potatoes on Mars. Lived off of them and ketchup for a long time, and the ketchup ran out.
lol I wondered how long it would be before someone got it
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.
[1]: https://gardenculturemagazine.com/growing-hydroponics-in-spa...
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?
Yes, but it requires said imaginary window.
Underground just requires LEDs and solar panels. Both of which we can make quite cheaply.
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.
I thought there are some regions in the North Pole that are constantly illuminated. Presumably the temperature is significantly more stable in those regions.
> There's absolutely no reason to do anything above ground on the Moon
Is there a reason to do anything below ground? We already aren't doing anything above ground.
Radiation is a serious problem. It tears apart DNA & RNA. Blocking radiation takes lots of material, hence, underground.
That's not a reason to do something below ground on the moon. It would be a reason not to do something above ground, which, as I noted, we already don't do.
I've moved beyond not doing things on the moon. That's so passé. I'm already not doing things above ground (or below ground on Mars) and have no plans for the moons of Venus after that.
> Ideally, you'd seal a lava tube and put in air and you could live in it with the plants being natural oxygenators.
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.
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.
[1] https://www.youtube.com/watch?v=xWRkzvcb9FQ
> Because you'd grow things underground
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?
> 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.
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.
How hard would it be to find and de-orbit a carbonaceous asteroid or two?
I thought Musk said some time back that SpaceX was sending people to Mars next year. How did they not already know this?
You can choose any year from the calendar, and there would be a Musk statement that says we'd be on Mars that year.
You might as well ask a fortune teller instead of listening to what Musk has said
Truth doesn't matter to him as long as it brings hype.
Maybe he did, but not recently.
He posted this several days ago: https://x.com/elonmusk/status/1837908705683059166
I find it interesting that he thinks being nuked every two years is a benefit to being so far from an out of control Earth. I’ve seen BSG and know nukes can fly in space.
He also baked in an out for himself. Now, if Kamala Harris wins the Presidency, he can say that she prevented from totally doing the thing he said he was going to do.
Sending humans to mars is difficult.
5 unmanned mission in the 2026 launch window, manned mission to follow in 2028 if the unmanned are successful is the most recent statement (though some reports garbled that into all 6 happening by 2026.)
I'm not saying 5 successful unmanned missions are impossible in 2 years, but I think Elon may have slightly underestimated the difficulty of the task. There is a lot of stuff left to develop still and very little time to do it.
Elon is not great at estimating how long tasks will take. He originally promised that full self driving would be complete by 2018.
Note that its not so much five in two years as five in a narrow window that opens in two years; they’d be near-simultaneous missions, on whose success would depend the manned mission when the subsequent launch window opened.
But, yeah, Musk timelines are not something I would put a lot of faith in.
"Next year" in Musk years means they have at least 6 years to get it right.
Snark aside, SpaceX may be thinking of MREs instead of growing food.
I think he said an unmanned mission in two years and humans in 4 or 6 years.
And you have to at least double any Musk time estimate.
Vastly under-estimating the magnitude of the task is how the crazy things get done.
Christopher Columbus wasn't unique in believing the world was round, he was rather unique in his vast under-estimation of the distance to Asia. The only reason he survived is dumb luck that the Americas were about where he thought Asia was. All of his doubters were correct that he would die before reaching Asia.
Of course, this way, way far down the list of reasons not to take Christopher Columbus as a role model.
Could SpaceX make a Starlink that revolves around the moon and could transmit imagery back to Earth?
What you are describing is a satellite.
Well, then there’s the beaming back to Earth. Maybe that’s easy…I wasn’t sure. Thx for the snark, tho.
No I get it. The words we use to describe things change over time with what we are exposed to. Starlink made satellites sexy again.
...and there have been a few satellites in lunar orbit, and even a private/commercial orbiter (capstone) recently https://www.advancedspace.com/missions/capstone/