Growing Plants In Lunar Gravity

smooth wombat writes "If everything goes according to plan, an experiment designed to test whether plants can grow in the limited lunar gravity will hitch a ride with a competitor for the Google Lunar X Prize. 'The current prototype for the greenhouse is a 15-inch-high (37.5-centimeter-high) reinforced glass cylinder that's about 7 inches (18 centimeters) wide on the bottom. Seeds for a rapid-cycle type of Brassica plant — basically, mustard seeds — would be planted in Earth soil within the container.' The press release from Paragon Space Development Corporation outlines its partnership with Odyssey Moon to be the first to grow a plant on another world. In addition to the experiment, Paragon will be helping Odyssey with the thermal control system and lander design. To win the prize, Odyssey must land its craft on the lunar surface by the end of 2014."

Comments

Paragon Firsts

[quercus.aeternam]

I'm somewhat surprised that I hadn't heard of Paragon - they seem to have done some very interesting experiments.

I was interested in seeing if it was like a biosphere, or how much regulation would be required. Unfortunately (according to TFA), they haven't actually designed anything yet.

It will also be interesting to see how the plants handle having a lunar day to complete their life cycle. It would be very cool if the plants were able to perpetuate for a while - even if only for a few days/cycles.

I for one will be quite interested in how this develops...

Rapid growth

[Joebert]

Has anyone else ever wondered if it would be possible to grow something almost instantaniously if the conditions were absolutely perfect ?

I would think that plants would grow faster with little to no gravity.

Why?

[SmallFurryCreature]

The splitting of the cells, the growing of said cells, keeping the cells supplied with nutrients, that is what limits the growth of a plant. Not silly gravity. Gravity has an effect (perhaps) on the shape of the plant. I could imagine that with less gravity a tree would be more upright, its branches not bending down by their own weight. There might be a reduction in the cost to pump the sap around although you got to wonder if gravity is not actually used in this process.

But hey, smarter people then me and you have tried thinking about this, didn't come up with a clear answer so they decided to do an experiment. Soon we will know or have another hole in the moon.

Re:Why?

[Takichi]

The direction of gravity and the direction of light both have an effect on plants ability to grow "up". They're labelled gravitropism and phototropism respectively. With gravity, they believe that starchy balls sink with gravity, put pressure on the cell membrane, and start a chemical chain of messages. So gravity does have an effect on the direction of growth, although it might not be as noticeable if there is a strong phototropic effect. As for cell growth, I'm not sure about the effects. At least, that's what I can remember from my plant physiology course.

Re:Why?

[Takichi]

Actually, I should add that the gravitropic effect is relevant to the root system of the plant. It helps the plant push down into soil, finding more nutrients, so low gravity definitely could affect plant growth if it is has a poorer ability to find and absorb resources.

Re:Why?

[WindBourne]

How are you certain of that? Some plants grow upside down just fine, while others fail. More likely than not, when this was first tried, I would bet that most ppl thought that ALL plants would fail, or succeed, not just some of them. Simply put, we do not know UNTIL it is tried. I am guessing that some plants will do just fine, and others will fail miserably.

Lunar sunshine and lunar soil

[DeltaQH]

Rather than answering the question about if a plant can grow in lunar gravity, I think it would be far more interesting to know if a plant can grow on lunar soil and with lunar sunshine.

Not directly of course! But what kind of soil treatment, additives and sunshine/radiation filtering would have to be done to be able to grow plants on a moon based greenhouse.

The question is. How much of what the moon offers can we use to grow plants there, and what adaptations must be done both to lunar based greenhouse and plants to use as much of moon resources as possible?

Sunshine during the day doesnt seem to be a problem in the moon ;-)

But those cold long nights :-(

What about a near polar location with eternal sunlight? For example along the rim of the crater Peary

Re:Lunar sunshine and lunar soil

[rts008]

There's no weathering on the moon; the "soil" is dust and grit with very sharp points and edges.[...]
The point is, you'd have to process your lunar resource of choice somehow; you can't use it "straight up."

I was wondering about that myself.
I also would think the fine dust that is present in large amounts would cause something similar to 'root rot' due to lack of air space between the soil granules/particles.
Once that fine dust becomes wet, it will pack tightly. I think this could pose a significant problem under low gravity conditions.

We may have to also rethink some of our 'dirt working' techniques. Most of our soil processing and our 'earth-moving' equipment/machinery utilizes both gravity and kinetic effects. Low gravity will have an effect here.
Having lived on a farm, and operated front-end loaders and dozers, I do have a little practical experience with both growing plants and 'dirt work'.

But, botany and geology are not my fields, so I may be just chasing my tail here.

Re:Plants grow in microgravity.

[Maelwryth]

Yes, that was my thought to. I was thinking more about larger plants though. Would fruit still grow the same shape under lunar gravity? Would you have to ration water to the plants so they don't suck up to much water and collapse? Would they have similar problems with nutrient loss as we do with calcium? Could be a very interesting experiment indeed.

It does appear there have been some preliminary studies done. Including growing Arabidopsis thaliana on the ISS. And rice on the Space Shuttle STS-95 mission. The abstract does mention some elongation in the coleoptile of the rice. I would imagine the bigger the plant, the bigger the changes that would develop. It is, after all, studying the effect of gravity.

Re:What about...

[ortholattice]

With a centrifuge, the experiment could be done on the Space Station, rotating at the right speed to emulate the moon's gravity. Still expensive, but not as much as a lunar surface version.

On the other hand, it might be useful to run a centrifuge on earth and emulate say 1g + n*0.1g for n = 0 to 10. We could look at the resulting curve and extrapolate backwards. That of course assumes the extrapolation is meaningful, but it might give a rough indication of what to expect with very little expenditure.

Sealed fate in a carboy

[G3ckoG33k]

In August 1997, I sealed a 20L glass carboy (http://en.wikipedia.org/wiki/Carboy) with desinfected soil and watertrumpet plants (http://en.wikipedia.org/wiki/Cryptocoryne). The water is only 40 mm deep just covering to root system. It just thrives!

There are seasonal deaths of individual leaves and various succesions of fungus growths, in white, yellow and brown. The "ecosystem" has not crashed yet on me.

However, I have not yet tested low gravity. That would be an effort beyond my budget...

.

Re:Bio power source.

[sketerpot]

NASA's miniature nuclear reactor for the moon would be more practical. It's about the size of a trash can.