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I was part of the USU team mentioned in the article. There are a lot of variables to take into account when growing plants in micgrogravity: Particulates, like

I was part of the USU team mentioned in the article. There are a lot of variables to take into account when growing plants in micgrogravity: Particulates, like soil, are actually considered a hazardous material in space because it can float into and clog up the ventilation. Capillary action is a dominant force in microgravity and water will coat everything. Roots are respiratory and will absorb the oxygen in the water around them, but the bubbles of CO2 they create won't naturally rise to the surface. This can cause the roots to suffocate. Hydroponics are the logical route because regular soil will deplete its nutrient supply, but you still need a root growth substrate. The current "Veggie" system uses vermiculite clay chips contained in a pouch. They had to use the right gauge of particle diameter though: too small and it will saturate with water and suffocate the roots, too big and there won't be enough pressure gradient from the capillary action and the roots will dry out. Also, if you don't have your hydroponic nutrient solution just right, salts will build up in your substrate, so the pouches are typically single use. Our team developed a method for 3D printing a growth substrate. This eliminates the problem with particulates and it also allows you control the gauge of the holes in the material to get the right air/water ratio. You can even vary the hole sizes so the water is pulled by the capillary action more at the dry end and fills the medium more evenly with water. It's not a perfect solution. The hydrophilic nylon filament we used liked to warp when it was printed. It also doesn't work for root vegetables like potatoes and stuff. However, it is reusable, cleanable, recyclable, scalable, largely passive, and safe. Plus, everyone loves 3D printers. TL;DR Microgravity creates a lot of problems for growing plants in space, many of which aren't immediately obvious. 3D printed growth mediums might be a solution.

mtchtrnr 10y ago
(BTW... I recently graduated and am looking for a job. If anyone has any leads for a mech/aero engineer with some programming background, please get in touch via my profile )
- grouplinkdave 10y ago
  Reading through the comments from the main article it seems the commentators are in two camps: 1) "...let's improve our engineering capabilities to solve this intriguing challenge..." [and later enjoy all the other side-benefits that come from being great engineers and problem-solvers]; and 2) why challenge ourselves in the first place [?]. I like to encourage and invest in visionary [and realistic] problem-solvers. Let's connect on that.
sfifs 10y ago
Serious question. Given all the difficulties with impact of microgravity on human beings and in this case plant cultivation, why isn't there more serious research/testing of generating artificial gravity through rotation? We only seem to see that in science fiction, never in real life.
- zardo 10y ago
  There was a project to install a small rotating ring module on the ISS, but it never came to fruition. A capsule tethered to a second stage, or a pair of capsules is the low-cost* way to do it. The technique was demonstrated during the Gemini missions (at very low g). *Compared to rotating space station As to why... I suspect non-ISS life science research in orbit just has no where to get funding or support.
- Mikeb85 10y ago
  I imagine building such a spacecraft is a relatively large undertaking. More centrifugal force means a larger diameter spacecraft and a force that is trying to rip it apart (that's what's generating the gravity after all). With NASA's current budget, they probably figure it's easier to just deal with microgravity for a spaceflight with a limited duration (like to Mars). Generating gravity only really makes sense for spaceflights of longer/unlimited duration (interstellar travel).
- mtchtrnr 10y ago
  Well, for humans it's because you'd need a really big ring to make it actually feel right. If the ring is too small, the difference in outward force created in your head and your feet will be different enough that your blood will rush to your feet and make you pass out. For the most part, your garden variety of plants wouldn't be affected too much by the force gradient. There actually has been quite a bit of research put into this. I'm trying to find a source for this, but a few years back the Japanese burned a bunch money on this kind of research and didn't end up with anything substantial. If you do it on a smaller scale, just for the plants, it also creates the issue of extra angular momentum added to your spacecraft. This is manageable, but definitely something to take into account. But, you're right. If you created gravity on a scale large enough for humans, it would definitely get rid of most of the problems for the plants.
grouplinkdave 10y ago
Reading through the comments from the main article it seems the commentators are in two camps: 1) "...let's improve our engineering capabilities to solve this intriguing challenge..." [and later enjoy all the other side-benefits that come from being great engineers and problem-solvers]; and 2) why challenge ourselves in the first place [?]. I like to encourage and invest in visionary [and realistic] problem-solvers.
- dekhn 10y ago
  camp 3 (I'm in this one): instead of spending money on humans in space, let's spend that money on robots in space. Once you don't have to deal with all the ugly details of keeping humans alive in space, you have a lot more budget for exploration, discovery, science. You can cover a lot more areas, and the likely payoffs are higher. Growing crops in space has no real scientific benefits for the nearterm future. It's a "nice to have" not a "visionary" thing.
  - Arizhel 10y ago
    We already have robots in space, such as the Mars rovers. It doesn't work that well: the round-trip communication time is very long, so it takes a long time for mission controllers on the Earth to get data from the robots, make a decision, and send that back. By contrast, a geologist walking around on Mars can make his own decisions on the spot and get a lot more done, much more quickly.
    - dekhn 10y ago
      I've heard the same about the moon (https://en.wikipedia.org/wiki/Harrison_Schmitt https://en.wikipedia.org/wiki/Harrison_Schmitt specifically """While on the Moon's surface, Schmitt — the only geologist in the astronaut corps — collected the rock sample designated Troctolite 76535, which has been called "without doubt the most interesting sample returned from the Moon".[8] Among other distinctions, it is the central piece of evidence suggesting that the Moon once possessed an active magnetic field.[9]""" . It was true at that time only because we didn't have good robots. The science resulting from our robot exploration is astounding. Nearly all photos of outer space objects beyond the earth and moon are robot driven, and the high quality photos of Jupiter, etc are entirely robot driven. Compare that to a Mars rock. BTW, we can't send a human to Mars right now. It's technically impossible- well, I mean, we could deliver their dead body to the surface, but that's not super useful. A single geologist on Mars would constantly have to check back in on their plans.
IndianAstronaut 10y ago
Do you have a link to your 3D printed growth substrate or an info page?

mtchtrnr 10y ago

(BTW... I recently graduated and am looking for a job. If anyone has any leads for a mech/aero engineer with some programming background, please get in touch via my profile )

grouplinkdave 10y ago
Reading through the comments from the main article it seems the commentators are in two camps: 1) "...let's improve our engineering capabilities to solve this intriguing challenge..." [and later enjoy all the other side-benefits that come from being great engineers and problem-solvers]; and 2) why challenge ourselves in the first place [?]. I like to encourage and invest in visionary [and realistic] problem-solvers. Let's connect on that.

sfifs 10y ago

Serious question. Given all the difficulties with impact of microgravity on human beings and in this case plant cultivation, why isn't there more serious research/testing of generating artificial gravity through rotation? We only seem to see that in science fiction, never in real life.

zardo 10y ago
There was a project to install a small rotating ring module on the ISS, but it never came to fruition. A capsule tethered to a second stage, or a pair of capsules is the low-cost* way to do it. The technique was demonstrated during the Gemini missions (at very low g). *Compared to rotating space station As to why... I suspect non-ISS life science research in orbit just has no where to get funding or support.
Mikeb85 10y ago
I imagine building such a spacecraft is a relatively large undertaking. More centrifugal force means a larger diameter spacecraft and a force that is trying to rip it apart (that's what's generating the gravity after all). With NASA's current budget, they probably figure it's easier to just deal with microgravity for a spaceflight with a limited duration (like to Mars). Generating gravity only really makes sense for spaceflights of longer/unlimited duration (interstellar travel).
mtchtrnr 10y ago
Well, for humans it's because you'd need a really big ring to make it actually feel right. If the ring is too small, the difference in outward force created in your head and your feet will be different enough that your blood will rush to your feet and make you pass out. For the most part, your garden variety of plants wouldn't be affected too much by the force gradient. There actually has been quite a bit of research put into this. I'm trying to find a source for this, but a few years back the Japanese burned a bunch money on this kind of research and didn't end up with anything substantial. If you do it on a smaller scale, just for the plants, it also creates the issue of extra angular momentum added to your spacecraft. This is manageable, but definitely something to take into account. But, you're right. If you created gravity on a scale large enough for humans, it would definitely get rid of most of the problems for the plants.

grouplinkdave 10y ago

Reading through the comments from the main article it seems the commentators are in two camps: 1) "...let's improve our engineering capabilities to solve this intriguing challenge..." [and later enjoy all the other side-benefits that come from being great engineers and problem-solvers]; and 2) why challenge ourselves in the first place [?]. I like to encourage and invest in visionary [and realistic] problem-solvers.

dekhn 10y ago
camp 3 (I'm in this one): instead of spending money on humans in space, let's spend that money on robots in space. Once you don't have to deal with all the ugly details of keeping humans alive in space, you have a lot more budget for exploration, discovery, science. You can cover a lot more areas, and the likely payoffs are higher. Growing crops in space has no real scientific benefits for the nearterm future. It's a "nice to have" not a "visionary" thing.
- Arizhel 10y ago
  We already have robots in space, such as the Mars rovers. It doesn't work that well: the round-trip communication time is very long, so it takes a long time for mission controllers on the Earth to get data from the robots, make a decision, and send that back. By contrast, a geologist walking around on Mars can make his own decisions on the spot and get a lot more done, much more quickly.
  - dekhn 10y ago
    I've heard the same about the moon (https://en.wikipedia.org/wiki/Harrison_Schmitt https://en.wikipedia.org/wiki/Harrison_Schmitt specifically """While on the Moon's surface, Schmitt — the only geologist in the astronaut corps — collected the rock sample designated Troctolite 76535, which has been called "without doubt the most interesting sample returned from the Moon".[8] Among other distinctions, it is the central piece of evidence suggesting that the Moon once possessed an active magnetic field.[9]""" . It was true at that time only because we didn't have good robots. The science resulting from our robot exploration is astounding. Nearly all photos of outer space objects beyond the earth and moon are robot driven, and the high quality photos of Jupiter, etc are entirely robot driven. Compare that to a Mars rock. BTW, we can't send a human to Mars right now. It's technically impossible- well, I mean, we could deliver their dead body to the surface, but that's not super useful. A single geologist on Mars would constantly have to check back in on their plans.

IndianAstronaut 10y ago

Do you have a link to your 3D printed growth substrate or an info page?