Lunar astronauts could potentially make hummus with moon-grown chickpeas

Nov 25, 2019
45
16
4,535
Visit site
All these "how to grow food in space" articles are pointless. OK maybe the science is interesting but in practical terms a human needs about 2000 kilo-calories per day to live. and that works out to about one million Kcal per year, allowing for some waste.

How many chickpea plants must you grow to get a million calories? OK you don't like Hummus, what about =wheat or rice or tomatoes or potatoes or corn. How many plants must you grow to make a million calories?

It works out to roughly one football field sized farm per =astronaught. more or less.

This is not surprising because on Earth out farmland ios MUCH larger than out "city land'. A city on Mars or the Moon would be trivial compared to the farm that feeds the city because every person needs a million Calories per year.

It gets worse... The part of the plant you eat is not even close to 100%, You need space to recycle the stems and leaves and let them decompose. Worse, you can't use natural sunlight because the thin window that lets in light also lets in radiation that will kill the plants. You need a few meters of rocjk and dirt over the planet to shield them and then grow lamps over you entire farm to allow photosynthesis. The nuclear power for the lights and heaters to keep the plant alive.

A cheaper solution is to get a glass tube and glow algae inside. The tubes can be dense-packed with lamps and a water pumps circulated the algae to a processing plant where is is made to something a person would want to eat. But still You need to make literally "truckloads" of food for each human.

The better solution is robots. In time robots can do any task and humans will not be needed in space. Except for tourism. Tourism is the only task a robot can't do for you.

On Earth and in space, farms will always be MUCH larger than cities.
 
  • Like
Reactions: motie and billslugg
Sep 1, 2020
14
5
4,515
Visit site
All these "how to grow food in space" articles are pointless. OK maybe the science is interesting but in practical terms a human needs about 2000 kilo-calories per day to live. and that works out to about one million Kcal per year, allowing for some waste.

How many chickpea plants must you grow to get a million calories? OK you don't like Hummus, what about =wheat or rice or tomatoes or potatoes or corn. How many plants must you grow to make a million calories?

It works out to roughly one football field sized farm per =astronaught. more or less.

This is not surprising because on Earth out farmland ios MUCH larger than out "city land'. A city on Mars or the Moon would be trivial compared to the farm that feeds the city because every person needs a million Calories per year.

It gets worse... The part of the plant you eat is not even close to 100%, You need space to recycle the stems and leaves and let them decompose. Worse, you can't use natural sunlight because the thin window that lets in light also lets in radiation that will kill the plants. You need a few meters of rocjk and dirt over the planet to shield them and then grow lamps over you entire farm to allow photosynthesis. The nuclear power for the lights and heaters to keep the plant alive.

A cheaper solution is to get a glass tube and glow algae inside. The tubes can be dense-packed with lamps and a water pumps circulated the algae to a processing plant where is is made to something a person would want to eat. But still You need to make literally "truckloads" of food for each human.

The better solution is robots. In time robots can do any task and humans will not be needed in space. Except for tourism. Tourism is the only task a robot can't do for you.

On Earth and in space, farms will always be MUCH larger than cities.
Agreed. If you build a greenhouse on the surface of the moon or Mars, the covering will need to be transparent to visible light (which is what the plants need); it will need to block short wavelengths; it will need to block high-energy particle radiation; it will need to survive a pressure difference of about one atmosphere from inside to outside; it will need to keep the inside at the right temperature while the outside temp is varying by hundreds of degrees. Good luck with that. An underground growing tunnel is probably the only good solution. Then there are the infrastructure requirements (water, energy, etc.).

On Mars, there is the problem of toxic perchlorates in the soil.

If you carry seeds on a spaceship to Mars, and it takes six months, will the seeds still be viable? Or will their DNA be fried by radiation? I don't know.

Mars as a backup planet is a nice thought, but IMO we are not nearly ready to pursue it at present. Meanwhile, robotics and AI are improving fast.
 
Nov 25, 2019
45
16
4,535
Visit site
Mars as a backup planet is a nice thought, but IMO we are not nearly ready to pursue it at present. Meanwhile, robotics and AI are improving fast.
"Mars as a backup is not even logical. Let's say there is a disaster scenario on Earth like this: Global warming. is left unchecked and it gets to the point where agriculture is impossible in many places of the world. War breaks out as starving people fight over the remaining water and livable land, this leads to a global six-way nuclear war. Industry and cities are gone and much of the world is radioactive. People are using self-made stone tools and eating bugs and roots. Few people live to be 30 years old. 95% of the human population was killed in the war or the after effects. Pandemics like a resurgence of the Black Death run unchecked. Dead bodies are common with no means to dispose of them. Then as luck would have it an asteroid of the size that killed dinosaurs impacts the Earth and makes things even worse.

The above scenario is not good. But even if it all came to be, the Earth would still be like paradise compared to Mars. On Earth at least there is air pressure and liquid water and a magnetic field and to survive all you need is stone-age technology. On Mars without advanced 22nd-century technology, you'd be dead in seconds.

Or to say it differently, if you could build an underground city and underground farms on Mars all powered by Fusion energy and maintain artificial closed ecosystems on Mars. Then with far less effort, you could do all of those things on Earth. In fact you would have to. Who would build such things on Mars without first testing the technology on Earth?

I think Mars and the Moon will be like Antarctica, places where some scientists go to and live for some time then come home and a place where rich tourists can go. We don't build cities in Antarctica because no one really wants to live there forever and it's too expensive.

Again, it is hard to think of a way that Earth could ever be a worse place to live than Mars and if it does happen then whatever technology you would use to live on Mars could be used on Earth.
 

Latest posts