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‘I sprouted, thrust into this world without anyone consulting me...I am

utilitarian, hearty vegetative matter that can thrive under harsh conditions. I am zucchini — and I am in space.’

The year was 2012. Don Pettit, an astronaut, initiated a strange writing project on NASA’s website named Diary of a Space Zucchini. The blog took the perspective of an actual zucchini plant on the International Space Station. Entries were insightful but strange.

Almost a year later, NASA planned to send romaine lettuce planters to the International Space Station. The project was to investigate the feasibility of crop production in Mars-like environments with a longer-term objective to grow soybeans and grains. Such space-farmed products would cut down the supplies astronauts need to carry with them; offer them with a tastier and more nutritious diet; and even afford some psychological comfort.

According to Howard Levine, project scientist for NASA’s International Space Station and Spacecraft Processing Directorate, it costs roughly $10,000 to send food to space. As such, success of growing food in space will potentially solve one of the biggest issues of space travel: the price of eating.

The microgravity farm system, nicknamed Veggie, produced its fi rst round of crops about one year ago. Veggie is a 1.5 foot-long capsule that glows like purple jellyfi sh. Its unique design

is collapsible for transport and storage. Inside the capsule there are provisions for growing six romaine lettuce plants.

Orbital Technologies Corporation (ORBITEC) in Madison, Wisconsin, developed Veggie in collaboration with NASA. NASA and ORBITEC engineers at NASA’s Kennedy Space Centre in Florida designed the unit in a fl ight-certifi ed fashion to allow use on the space station. The weird purple glow results from the lights similar to those used in greenhouses on Earth. To get the plants going in the right direction, Veggie has been provided with 132 red, 32 green and 32 blue LED lights, says Gioia Massa, the scientist in charge.

RIDDHI DATTA

Within the Veggie, plants can grow well with just the red and the blue lights and carry on photosynthesis. However, under this condition, the plants look pretty unappetizing to humans – grey-purple in colour. The green lights solve this problem.

With all conditions adjusted, Veggie has successfully produced lettuce in the orbits. “If you can get the environmental conditions correct, there’s no reason why plants won’t grow pretty well in space,” says Massa.

The main hurdle for growing plants in space is the lack of gravity. The soil tends to fl oat away. The solution has been

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Romaine lettuce growing inside the Veggie at International

Space Station.

Science Reporter, JUNE 201647

of weightlessness on plant growth, rather than focussing on how to provide the crew with a food source. With the success of the Veggie program, there will be a massive change in the research thrust in NASA. If NASA is ever going to send astronauts to Mars, they will have to be self-suffi cient because the missions will last for at least three years and astronauts will not be able to carry enough food supplies.

The Veggie project has helped the NASA scientists to learn how to grow fresh food for the crews of impending space missions. Future experiments will embrace new plants such as dwarf tomatoes and dwarf peppers.

Growing vegetables in space might have additional advantages too. “The psychology of having something growing you can eat, it’s very satisfying — most of the time, when you’re not fi ghting off pests or something,” Massa says. However, whether they have as yet spotted any pests to spoil the extra-terrestrial garden has not been disclosed.

NASA scientists are planning for a two-way deal: astronauts will nourish their salad crops with their own waste fl uids. Each Veggie module will scavenge chemicals from astronaut urine to produce fertilizer. The system will be tested in the unfriendly wastes of Antarctica in 2016.

Ms Riddhi Datta is an Assistant Professor at the Government General Degree College, New Town, Rajarhat, Kolkata. She is an alumnus of Presidency College, Kolkata and Gold medallist in Botany in B.Sc. (Hons.) as well as M.Sc. courses from University of Calcutta. She is pursuing PhD in Plant Biology at the CSIR-Indian Institute of Chemical Biology, Kolkata. Address: R-40, Kamdahari, Garia, Kolkata-700084, West Bengal; Email: riddhi.bot@gmail.com

to design something comparable to a grow bag or a root-mat. The space agency calls these ‘plant pillows’.

Another obstacle is watering the plants in weightlessness. Instead of draining away, the water pools around the roots, effectively overwatering the plant. Veggie has a simple yet effi cient strategy to solve this problem. There is a reservoir of water at its base, which is covered with a permeable fabric. A similar fabric is also present on the underside of the plant pillow and allows water to seep into the soil. A system of wicks then guides the water to the individual plants. The wicks also keep the plants upright. Normally, plants sense gravity and orient their growth accordingly. But there is no gravity in space. Hence, the seeds are glued on the wicks in the right direction. After germination, light is used to direct growth.

There is also a fan, drawing air from the station’s internal atmosphere up and passing it out through a vent, sending

oxygen out and carbon dioxide in. The system is called ‘bellows’ and provides a bonus air cleaner for the International Space Station.

Since there is no way to wash vegetables on the space station, Massa and her colleagues had to verify that the produce is safe to eat. Therefore, inside the special growth chamber, seedlings were placed on the Veggie root-mat pillows, and their growth was scrutinized for health, size, amount of water used, and the micro-organisms that grew on them. The fi rst batch of the space-farmed lettuce was sadly sent back to Earth un-tasted for necessary analysis.

“We test for E. coli and Salmonella, the standard food pathogens. We also test total fungi, yeast and molds,” says Massa. The space lettuce’s microbes matched up closely with those found on a control group grown on the ground. “In general, I’d say these plants are cleaner than what you’d get at the grocery store,” she added.

For the second round, once the new lettuce fi nishes growing, the astronauts will be given a chance to try few leaves after wiping them down with sanitising wipes. “The last thing you’d want is to get food poisoning in space,” Massa says. They will set aside half of the harvest and ship them back to Earth for further tests.

Until now, USA had directed their plant experiments in space towards understanding the effect

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Lettuce growing inside the bellows of a prototype Veggie

fl ight pillow

A scientist checks the lettuce growing inside the Veggie

The extra-terrestrial lettuce appears purple under the LED light inside the Veggie chamber but green when taken out