Lesson 5 Exploring the Universe
How to Grow Greens in Space
In the ____ The Martian, the hero Mark Watney is an astronaut struggling to stay alive on Mars.
In order to survive, he grows potatoes in the Martian ____.
Could it really be ____ to grow plants in space on Mars or on the moon?
The answer is partly no, because we have not had the opportunity to ____ growing any plants on Mars or on the moon.
But the answer is also yes, because we have been growing plants in space in the ____ environments of various spacecraft for several years.
In the early days of space travel, plants were grown on spacecraft primarily for research purposes —- to better understand how they functioned and ____ they grew under different conditions, such as in microgravity and closed environments.
In recent years, however, NASA has seriously started investigating the potential of space-grown plants as a food source for ____.
Fresh food provides valuable nutrients as well as variety from the dried and packaged food that makes up most of an astronaut’s ____.
Therefore, finding a way to continually supply astronauts with fresh food ____ long been a desire for NASA.
In the movie The Martian, the hero Mark Watney is an astronaut struggling to stay ____ on Mars.
In order to survive, he grows potatoes in the ____ soil.
Could it really be ____ to grow plants in space on Mars or on the moon?
The answer is partly no, because we have not had the opportunity to try growing any ____ on Mars or on the moon.
But the answer is also yes, because we have ____ growing plants in space in the confined environments of various spacecraft for several years.
In the early days of space travel, plants were grown on spacecraft primarily for research purposes —- to better understand how they functioned and how they grew under ____ conditions, such as in microgravity and closed environments.
In recent years, however, NASA ____ seriously started investigating the potential of space-grown plants as a food source for astronauts.
Fresh food provides valuable nutrients as well as variety from the dried and ____ food that makes up most of an astronaut’s diet.
Therefore, finding a way to continually ____ astronauts with fresh food has long been a desire for NASA.
In addition to health benefits
In addition to ____ benefits, a bit of space gardening can also offer psychological benefits for astronauts.
Observing and caring for ____ can relieve their stress and improve their moods.
Plants are a living, ____ piece of Earth; therefore, their smell and color can inject a bit of sensory variety into an artificial lifeless environment.
With the sun rising and setting as many as sixteen times a day on the ISS, ____ suffer from sleep disorders.
Space gardening can minimize this problem by ____ astronauts mark the passing of time.
While it is not yet happening on a large scale, plants grown on a spacecraft may be used to potentially reduce carbon ____ and produce oxygen, as well as provide water for drinking through transpiration.
In this ____, growing plants in space may help to provide a more habitable environment for humans.
Still, there are questions that need to be answered.
First, what essentials are needed for plants to be able to grow, and ____, in what ways can these essentials be provided on a spacecraft?
Plants must have water, soil, gravity, and ____, all of which are in short supply on a spacecraft.
Experiments over the years have ____ slowly but surely developing ways of growing plants in space with very little of these essential requirements.
____ is especially scarce on the ISS, and the amount used is controlled and recycled as much as possible.
About 93 percent of all water on the ISS is reclaimed from the collected breath, sweat, and even urine of the ISS inhabitants. It’s a ____ story with soil.
A spacecraft is not going to be able to carry around masses of heavy, dirty stuff that can be ____ to grow plants in.
In addition, soil and water ____ to float away because of the lack of gravity.
For these reasons, NASA has developed a special container called a Veggie, which is ____ designed for space-gardening on the ISS.
The Veggie creates a suitable artificial environment for plants to ____ and flourish under conditions of weightlessness.
It contains plant pillows and a reservoir. Plant pillows are ____ of dirt, fertilizer, and nutrients.
Small wicks that seeds are glued ____ are inserted into the bags to soak up the water.
A reservoir of water is at the Veggie’s base, and it is ____ with a fabric that allows the water to pass through it.
A ____ fabric on the bottom side of the plant pillow allows the water to soak into the soil.
What about gravity?
On Earth, gravity has been thought to be necessary for roots to grow in the right direction —- down and ____ from the leaves.
In a weightless environment, ____ is no up or down, so roots grow in all directions.
Research ____ in 2010 on the ISS, however, showed that gravity is not an important factor for plant growth.
This research proved that plants do not need gravity in order to grow normal ____ patterns and send their leaves upward toward the light.
____ grow more slowly, but as long as they have a light source above them, they are able to grow in the right direction.
The light source, however, needs to be sufficiently ____ and directed.
This intense light source is indispensable for ____.
On Earth, ____ plants get this light from an obvious, abundant source, the sun.
But in a spacecraft, the sun’s solar radiation is usually not best for plant growth because the position of the ____ is constantly changing.
Thus, NASA has adopted LEDs for the light source. LEDs use less ____ and last longer than old-fashioned lights.
LEDs emit little heat, so moving them closer to the plants ____ cause the plants to dry out or be burned.
Knowing how to grow plants in confined ____ is not just of benefit to salad-hungry astronauts.
Experiments with ____ production on the ISS have also proven valuable for agriculture on Earth, especially for areas in which water is scarce, soil is poor, or space is limited.
For example, vertical farming with an electric ____ source is now widely used in many countries.
Continued experiments in space gardening will give more insight ____ how plants can be grown successfully in challenging environments.
Space gardening is good not only for ____ in space but also for people on Earth, helping to solve the problems of how to face a changing climate and a growing world population.