Pioneer Labs announced sPL.001 today which is a microbe engineered to grow on Martian dirt & turn it into building material. The organism is Cupriavidus necator, a bacterium that naturally stores carbon as PHB, a bioplastic. The recipe is genuinely elegant: 40 grams of Martian regolith per liter of water supplies nitrogen & phosphorus, while the carbon comes from acetate made from atmospheric CO2 using a small electrocatalysis device. Dirt, water & air in, printable plastic out. The reason regolith is hard: it's heavily salted & contains 0.5 to 4% perchlorate, a bleach-like compound that kills most lab strains. Getting a chassis organism to grow in that at all is the achievement here. The idea isn't new, which is a point in its favor. A 2015 study estimated that C. necator producing PHB on Mars could cut the shipped mass needed to 3D-print a six-person habitat by 85%. Pioneer Labs is trying to actually build the organism. Now the caveats. This is a company announcement with no paper and no peer review yet. The claim that one rocket's equipment yields a small city's worth of material in four years is a model, not a demonstration. Despite the terraforming language, the microbe lives in sealed heated bioreactors - their own roadmap describes indoor biomanufacturing as a stepping stone toward an outdoor organism, which is a much harder problem. Still, the framing is right. You cannot ship a city. You can ship a bacterium and let it eat the planet.