{"group":"make","pic":"living/pics/factories-city.webp","question":"Where does a city get its steel when the nearest steelworks is on another planet?","answer":"From its own ships first, then from the ground. Old hulls are melted into bar and plate, and the red soil, which is full of iron, becomes new steel with hydrogen from the fuel plant.","play":{"label":"Walk the steel yard","href":"play/?era=city&light=dusk#yard"},"earth_mars":{"earth":{"head":"The shop is down the road"},"mars":{"head":"The city makes its own"},"pics":{"earth":"living/pics/em-factories-earth.webp","mars":"living/pics/em-factories-mars.webp"},"rows":[{"label":"A spare part","icon":"gear","earth":"Ordered today, delivered tomorrow.","mars":"Printed in the machine shop the same day, from plastic used again and again."},{"label":"Iron","icon":"layers","earth":"Dug from deep mines as ore.","mars":"Lying everywhere: the red soil is {fa_fe}% iron oxide."},{"label":"Old ships","icon":"rocket","earth":"Cut up for scrap at the end of their lives.","mars":"Melted down into the city's first steel."}]},"pin":[0.9,0.5],"sort":{"title":"Iron in every handful","line":"About {fa_fe_n} grains in every hundred are iron oxide. Tap the soil to sort them out.","button":"Sort the soil","again":"Mix it again","iron":"Iron-rich grains","rest":"Silica, alumina and the rest"},"steps_title":"From old ships to new steel","steps":[{"title":"Strip the ships","text":"Ships that will not fly again are cut into rings. Their stainless steel is the city's first metal."},{"title":"Melt","text":"An electric furnace melts the rings into bar, plate and wire. No coal and no smoke."},{"title":"Iron from soil","text":"Iron-rich grains are sorted from the soil and turned into iron with hydrogen from the fuel plant."},{"title":"Glass and wool","text":"What is left melts into dark glass, and spun into fibre it becomes the stone wool the farms grow in."}],"rust":{"title":"Steel from rust","line":"Hydrogen pulls the oxygen out of rust. What is left is iron.","boxes":{"soil":"Iron-rich soil","h2":"Hydrogen","furnace":"Hot reactor","iron":"Iron, then steel","water":"Water","split":"Split again at the fuel plant"},"text":"The water that comes off goes straight back to the fuel plant to be split into hydrogen again, so the loop barely needs topping up."},"energy":{"title":"Melting old steel is cheaper","line":"Electricity to make one tonne of steel, drawn to scale.","new":"New steel from soil, with hydrogen","old":"Old hull steel, melted down","unit":"MWh a tonne","text":"Melting old steel takes about {fa_x} times less power, which is why the ships become steel first."},"scene":{"pic":"living/pics/scene-factories.webp","look":"03-12","shot":"yard_dusk","focus":"50% 55%","zoom":1.6,"spots":[{"at":[0.23,0.6]},{"at":[0.4,0.54]},{"at":[0.68,0.42]},{"at":[0.87,0.6]}]},"proof":{"pic":"living/people/factories-proof.webp","place":"Meridiani Planum, Mars","when":"{fa_hs_year}","head":"Iron lying on the ground","credit":"Photo: NASA/JPL/Cornell, taken by the Opportunity rover (public domain)"},"fact":"In {fa_hs_year} the Opportunity rover found a rock {fa_hs_cm} cm across lying beside its own discarded heat shield. It was solid metal, {fa_hs_fe}% iron and {fa_hs_ni}% nickel: the first meteorite ever found on another planet.","quiz":[{"q":"Where does the city's first steel come from?","a":["Old ships that will not fly again","Iron mined deep underground","Steel bars shipped from Earth"],"why":"Ships that stay on Mars are cut into rings and melted in an electric furnace into bar, plate and wire.","more":"The first 3D printer reached the space station in {fa_p_year} and printed {fa_p_unique} different parts, including a working tool sent up as a file from the ground.","cite":"03-12 MF-03, F-08","from":"fix","fig":0,"icon":"rocket"},{"q":"What turns rust from the soil into iron?","a":["Hydrogen from the fuel plant","Heat from the Sun","Carbon dioxide from the air"],"why":"Hydrogen pulls the oxygen out of the rust and leaves iron. The water that comes off goes back to be split again.","more":"On {fa_hy_date} Sweden's HYBRIT project delivered the world's first fossil-free steel, made with hydrogen instead of coal.","cite":"03-12 MF-04, F-15","from":"why","fig":0,"icon":"flame"},{"q":"Why melt old steel rather than make new?","a":["It takes far less power","It comes out stronger","It comes out lighter"],"why":"Melting old steel takes about {fa_eaf} MWh a tonne. New steel from soil with hydrogen takes about {fa_dri} MWh.","more":"RepRap, a printer built to copy itself, printed a full set of its own printed parts on {fa_rr_date}: {fa_rr_pct}% of all its parts.","cite":"03-12 F-14, F-11","from":"why","fig":1,"icon":"bolt"}],"notes":[{"beat":"fix","text":"Window glass on Earth is about {fa_gl_si}% silica. Mars soil is already {fa_si}% silica, glass's main ingredient.","cite":"03-12 F-22, F-12"}],"everyday":{"title":"A day of making","items":[{"time":"08:05","head":"Printed before breakfast","text":"A cracked cupboard hinge? The machine shop prints you a new one while you eat.","tag":"Made in town","pic":"living/pics/factories-city.webp","pos":"30% 50%"},{"time":"14:30","head":"Sparks at the yard","text":"Out at the yard, a ship that carried families here becomes steel for their streets.","tag":"{fa_share_lo} to {fa_share_hi}% made on Mars","pic":"living/pics/scene-factories.webp","pos":"18% 60%"},{"time":"19:40","head":"Dinner grown in rock","text":"Tonight's salad grew in stone wool, spun from the plain's own volcanic rock.","tag":"Stone wool from Mars","pic":"living/pics/scene-food.webp","pos":"40% 55%"}]},"living":"Nothing here waits for a ship. Break a part and the machine shop prints you a new one by lunch, and out at the yard the ships that carried the first families become the steel of their streets.","from":"From the machine shop","later":{"pics":{"city":"living/pics/factories-city.webp","far":"living/pics/factories-far.webp"},"city":{"tag":"Ships into steel","text":"Old hulls melt into bar and plate, soil becomes iron and glass, and the machine shop prints the rest."},"far":{"tag":"Made on Mars","text":"Great bright halls make steel, glass and solar panels from the plain itself."}}}