101 on Living in Space
You have to Grow your own Food in Space
The Vegetable Production System (VEGGIE) primarily serves as a plant growth unit aboard the ISS. The state of the art low-power system develops fresh and nutrition-rich food for the astronauts. Fresh food provides psychological relaxation as well as the unique ability for continued nutritional sustenance.
The official objective of Veggie runs to the tune of: “The Vegetable Production System (Veggie) is a deployable plant growth unit capable of producing salad-type crops to provide the crew with a palatable, nutritious, and safe source of fresh food and a tool to support relaxation and recreation. The Veggie provides lighting and nutrient delivery and utilizes the cabin environment for temperature control and as a source of carbon dioxide to promote growth. Veggie is also used for fundamental space biology experiments such as the series Advanced Plant Experiments (APEX) and educational space biology activities.”
THE INSTRUMENT OF CHOICE
The present system supports two Veggie units and was constructed by ORBITEC. The technology itself was road-tested in NASA’s Kennedy Space Center before being installed on board the International Space Station through the CRS-3 SpaceX mission in 2014. The system was brought to life in the Columbus Laboratory Module on the 7th of May,2014. It is the largest volume available for plant growth on the ISS, having been installed in the EXPRESS (Expedite Processing of Experiments to Space Station) Rack.
WHAT’S UNDER THE HOOD?
At present, the Veggie unit uses 70 watts of energy for proper functioning. This is in pursuance of the low energy requirement of the system. A passive wicking system is used to water the seeds for the growth of the plant, wherein the seeds are affixed onto the wick itself. The glue used to attack the wick to the seed is guar gum, which is a common component of ice cream.
The growth medium is contained in a Kevlar-Nomex bag called Plant Pillows. It comprises calcined clay, attached to fertilizer and water through a quick-disconnect valve. The process by which the wicking system works is truly ingenious, utilizing a water reservoir called root mat to wick water into the plant pillow through the Nomex covering. Keeping in mind that each seed is besieged with myriads of reasons for failure, each Plant Pillow comprises three seeds each.
The plant pillows themselves with the seeds are installed onto the root mat, together being installed into the Veggie bellows
Watch in the video how Plants are watered in Space!
There are a million things which may go wrong in any experiments. However the VEGGIE system has been designed in a robust manner to persevere. The effects of microgravity alter the hydrodynamics and primarily convective flow. This issue is resolved through utilization of correctly sized granules of growth media, which equilibrates the concentration of water and air at the roots while fans draw in cabin air to provide the correct combination of humidity and oxygen with all diffusion parameters considered.
MILESTONES OF SUCCESS
The plant products obtained through this method are designed so that they can be easily cultivated and consumed, since there is no mode of cooking available yet aboard the ISS.
The first produce was planted on the 8th of May 2014 and comprised 6 plants pillows with seeds for Red Romaine Lettuce. After 33 days, three plants could be successfully harvested as one failed to germinated while two died of water stress. The analysis of the harvest yielded that the produce was far safer for consumption than those found in grocery stores.
In the second effort, initiated on the 8th of July 2015, 6 plant pillows containing Red Romaine Lettuce were germinated and harvested after 33 days. It was for the first time that half of the plant tissue from each plant was used as a consumable food source by the astronauts. In a flight of fancy, it was taken with a space cheeseburger too!
Plants also have been demonstrated to possess beneficial psychological effect. In pursuance of this aim, for the first time Zinnia seeds were planted in six plant pillows and allowed to germinate and flower.
This experiment also served as a precursor for the harvest of plants with fruiting bodies like tomato. The germination was carried out with seeds exposed to extra-terrestrial environment for a year and a half.
There was no depreciation in the quality of growth, and the plants were successfully sent back to earth to be analyzed and studied. It is of interest that seeds from these zinnia samples yielded more plants on earth too, indicating functional pollination in microgravity.
The various modules of the Veggie unit has yielded further plants for both human and non- human consumption. Apart from the Red Romain Lettuce, there was ‘Tokyo Bekana’ Chinses Cabbage, Mizuna Mastard, Waldmann’s Green Lettuce, Red Russian Kale, Dragoon Lettuce and Extra Dwarf Pak Choi.
These harvests were carried out with small variations in the protocols, as to the watering system, method of harvest, lights etc. In terms of experiments in plants which were not consumed, there was the first harvest of Red Romaine Lettuce, followed by Arabidopsis cultures, Zinnia, Lentil with mustard and Radish and Brachypodium. Of significance was the successful growth of Space Algae and Microalgae also.
The VEGGIE is an integrated system for successful harvest of plants in space. It has witnessed and yielded sufficient result to suggest that growing plants in long term Space Missions might not be a Herculean task anymore. Stay Tuned for the next update !