{"group":"grow","pic":"living/pics/food-city.webp","question":"How do you feed a city where nothing grows outside?","answer":"Indoors, in its own room. Salad, tomatoes, wheat, peppers, potatoes, strawberries, rice, beans, sweet potatoes, soybeans and peanuts glow under lamps in one long buried hall, and glass domes catch the thin Martian sunlight.","play":{"label":"Walk the farm hall","href":"play/?era=city#hall"},"play_also":[{"label":"Walk into a farm dome","href":"play/?at=-68,-107,1.47,0.2,12&era=city&light=day"}],"plot":{"title":"One person's farm","line":"Feeding one person takes about {m2} m² of crops: more than the smallest one-bedroom flat England allows ({flat} m²).","air":"{o2_lo} to {o2_hi} m² of it also makes all the oxygen they breathe.","stack":"Stacked {tier_lo} to {tier_hi} shelves high, the whole farm fits on {f_floor_lo} to {f_floor_hi} m² of floor.","flat":"Lay it flat","racks":"Stack it on shelves","key_food":"Food","key_air":"Food and all their oxygen","flat_label":"Smallest one-bed flat"},"light":{"title":"Half the sunlight","line":"Sunlight at Mars is {f_sun_pct}% as strong as at Earth, so the domes are topped up by lamps and the buried farms run on lamps alone.","earth":"Earth","mars":"Mars","power":"Lamps, fans and pumps for one person's food use about {kw} kW, day and night: like {f_kettles} kettles boiling non-stop."},"crops_title":"What grows fastest","crops_line":"Grams of plant grown on each square metre every day, in NASA's sealed test farm.","soil":{"title":"Why not Mars soil?","text":"Mars soil carries perchlorate, a salt that harms the thyroid. Roots grow in stone wool instead: rock melted and spun into fibres, made here from Mars basalt."},"grown":"{grown_lo} to {grown_hi}% of every calorie in Arcadia City is grown on Mars.","earth_mars":{"earth":{"head":"Fields grow in the open"},"mars":{"head":"Nothing grows outside"},"pics":{"earth":"living/pics/em-food-earth.webp","mars":"living/pics/em-food-mars.webp"},"rows":[{"label":"Sunlight","icon":"sun","earth":"{earth_sun} watts on every square metre above the air.","mars":"{mars_sun} watts: {f_sun_pct}% of Earth's."},{"label":"Temperature","icon":"thermo","earth":"About {earth_c}°C on average across the planet.","mars":"A summer day swings from {sum_lo}°C at night to {sum_hi}°C."},{"label":"Air and soil","icon":"air","earth":"Air you can breathe and soil crops can root in.","mars":"{mars_co2}% carbon dioxide, and soil with salts that harm people."}]},"living":"The farm hall glows magenta, room by room, from the lettuce to the peanuts, and smells of wet leaves and ripe tomatoes. Farm shifts are the ones everyone wants, and dinner is picked the same day.","fact":"In {veg_year}, astronauts on the International Space Station ate the first lettuce grown in space: red romaine from a plant box using just {veg_w} watts.","card":"food","pin":[0.9,0.48],"scene":{"pic":"living/pics/scene-food.webp","look":"03-10","shot":"racks","focus":"48% 50%","spots":[{"at":[0.17,0.42],"label":"Racks to the ceiling"},{"at":[0.31,0.13],"label":"Red and blue grow lights"},{"at":[0.53,0.22],"label":"Daylight down a shielded shaft"},{"at":[0.47,0.55],"label":"A farmer at the shelves"}]},"proof":{"pic":"living/people/food-proof.webp","place":"International Space Station","when":"{veg_year}","head":"The first salad in space","credit":"Photo: NASA (public domain)"},"quiz":[{"q":"What do the crops' roots grow in?","a":["Stone wool spun from Mars rock","Mars soil, washed and sieved","Soil shipped from Earth"],"why":"Mars soil carries perchlorate, a salt that harms the thyroid. Stone wool is rock melted and spun into fibres.","more":"Stone wool is made by blowing air through rock melted at about {wq_wool_c}°C, copying the glassy strands Hawaii's volcanoes blow from their lava.","cite":"03-10 F-16, F-18","from":"problem","fig":0,"icon":"layers"},{"q":"How strong is sunlight at Mars?","a":["{f_sun_pct}% of Earth's","About the same as Earth's","A tenth of Earth's"],"why":"Sunlight at Mars is {f_sun_pct}% as strong as at Earth, so the domes are topped up by lamps.","more":"In Antarctica, the EDEN ISS greenhouse grew {wq_eden_kg} kg of food on {wq_eden_m2} m² in {wq_eden_days} days, all under red and blue lamps.","cite":"02-01 F-14, 03-10 F-22","from":"why","fig":0,"icon":"sun"},{"q":"Which crop grew fastest in NASA's sealed test farm?","a":["Wheat","Lettuce","Tomato"],"why":"Wheat grew {wq_wheat} g on every square metre each day, more than any other crop tested.","more":"In China's Lunar Palace, teams of {wq_lp_size} took turns living sealed inside for {wq_lp_days} days in all, eating crops and mealworms grown a few steps away.","cite":"03-10 F-06, F-21","from":"why","fig":1,"icon":"bar"}],"notes":[{"beat":"fix","text":"NASA's sealed test farm grew {wq_bpc_edible} kg of food on just {wq_bpc_m2} m² of shelves, and made {wq_bpc_o2} kg of oxygen while it was at it.","cite":"03-10 F-12"}],"from":"From the farm halls","everyday":{"title":"A day of food","items":[{"time":"07:45","head":"Picked this morning","text":"Salad leaves cut at dawn are on the table by lunch. Almost every bite here was grown on Mars.","tag":"{grown_lo} to {grown_hi}% grown here","pic":"living/pics/scene-food.webp","pos":"40% 55%"},{"time":"13:00","head":"A shift in the halls","text":"Shelves stacked {tier_lo} to {tier_hi} high glow magenta under the lamps, heavy with lettuce, tomatoes and peppers.","tag":"{m2} m² feeds one person","pic":"living/pics/food-city.webp","pos":"40% 55%"},{"time":"19:30","head":"Dinner for the table","text":"Potatoes, rice, beans, salad and tilapia, every one of them raised right here in Arcadia.","tag":"Grown in Arcadia","pic":"living/pics/food-far.webp","pos":"55% 55%"}]}}