The “South Pole Food Growth Chamber” aka Greenhouse
Sometimes it’s easy to forget just how sterile it is here. We are all caught up in our jobs, our daily routine, but every now and then some small rocks and dust on a pallet from McMurdo or a bright bowl of freshies (apples, bananas, oranges, salad) in the galley brings it to mind. Walking through the station there are no plants, no windows overlooking green grass or trees, no animals…it’s just plastic and metal until you reach the Greenhouse. With the curtains drawn it’s almost easy to miss, but a bank of windows sits in the wall of the lower hallway between the Post Office and Quiet Reading Room (aka Library). Open curtains spill yellow sodium light onto the black hall floor…I push open the large freezer-type door and walk into the foyer – into a wall of humidity, warmth, and the smell of life and growing things. The sharp contrast between the dry, cool nothingness outside is almost overwhelming. The air feels thick, hard to breath at first. Approximately 10ft x 6ft, the foyer is filled with a blanket covered couch, small table, some edible flowers, and a stereo. This is separated from the “primary growth chamber” by large glass doors.
The "primary Growth Chamber" as seen from the small ante-room
At 70F and 60% humidity it’s a veritable sauna compared to the cooler 4% humidity air throughout the station. Just a few minutes of sitting in the antechamber relieves stress, renews energy, and generally lifts moods. Very rarely do I walk by and see the couch empty – many times it’s just one person with their head back, eyes closed, just breathing. Stepping into the Greenhouse calls up memories of tunneling through hay fields, climbing massive trees, rain drops on giant Pacific Northwest sword ferns, and the feeling of spongy bright green living grass beneath bare feet.
The Greenhouse is technically a NASA experiment; a hydroponic operation using water cooled sodium lights and a tightly controlled atmosphere with supplemented CO2. Consuming 140 litres of water and roughly 1.2 kg of CO2 per day, the system isn’t quite perfect, but it’s a HUGE moral booster.
The growth chamber consists of three rows of two tiered sliding trays. Carefully monitored nutrient/salt enriched water runs through the trays bathing the roots of the plants. To give structural stability to the roots they are grown in a matrix of vermiculite or more often, “rock wool.”
The trays can be pushed back underneath to make room to walk by
"Rock wool" provides structure for the roots and support for the leafy green above
At peak production the Greenhouse can produce up to 6kg per day of biomass, 2.8 of which is edible (the rest is a combination of roots/stocks/inedible leaves etc). This is enough for roughly 2 salads a day for the 40 people overwintering. During the summer with our population between 220 and 250 fresh greens augment flown in “freshies” – colorful nasturtium flowers, deep green waxy chard, and various types of curling crunchy kale are a welcome sight in the food line!
To protect this last continent from invasive species and to limit impact and disturbance the Antarctic Treaty prohibits growing anything inedible on the continent. You may laugh, but there are some places with exposed soil such as within the Dry Valleys and on some places along the Peninsula.
Some links to more info on the Greenhouse:
An interesting blog by our summer Greenhouse Tech John Rask: http://spacebiosciences.arc.nasa.gov/blog