In this episode of Voices from DARPA, synthetic biologist and program manager Justin Gallivan of the Agency’s Biological Technologies Office (BTO) shares his vision of leveraging biology’s astonishing, evolution-honed abilities for making molecules and materials (think here of protein and wood) into powerful new technologies that fall into the emerging category of synthetic biology. Among the potential payoffs he discusses include pre-toughening warfighters’ guts for the microbial challenges they face in faraway missions and growing the structures of military installations from what could be thought of as seeds. Be warned: blue poop and interplanetary construction come up in this engaging discussion.