Have you ever thought if plants can grow at the International Space Station in microgravity? Or does that sound impossible? If not impossible, what difference would growth of these plants have from the general ones on Earth?
At the ISS, NASA is conducting an experiment called Lada Validating Production Unit which uses a chamber similar to a greenhouse. The Lada greenhouse has been growing experimental plants since 2002. The research is based on plants, protocols, procedures and requirements for growing the plants at the space station. The purpose is to optimize production of clean and healthy food at the station to reduce the amount of food that needs to be carried to the station for consumption.
The question is, how does the microgravity of the ISS affect the plant growth. Plants use gravity only to orient themselves so that the sprouts go up and the roots go down. So, in the absence of gravity, the plant will not grow out of the soil. An astronaut reported that this problem could be solved by plucking the ends of the surface when the seed first sprouts. The roots simply grow away from the light, and the rest of the plant will orient itself to receive maximum light.
This way, the growth is normal just like the one on Earth. The only difference is that the plant will be very upright as there will be no dropping of leaves due to gravity.
Mizuna, a type of Japanese lettuce was grown on the ISS and brought to Earth through the space shuttle Discovery.
This fact gives rise to the questionable shape of trees if grown on the space station. Trees can only grow as high as their capability to draw nutrients and water to the top, working against the gravity. Once it reaches the limit, the tree stops growing. At the space station, with no restriction on water, nutrients, and space, theoretically, a tree could grow infinitely high as the resistance against gravity is minimal.
How tall do you think a tree can grow on the same station? Comment below!