Additive manufacturing, specifically inkjet printing (IJP) and aerosol jet printing (AJP), have shown great potential for rapid prototyping and direct writing of electronic sensors. These additive techniques provide the developer with much flexibility in controlling the sensor response through materials selection and system design. Recently, the research community has started exploring applications of additive manufacturing for extreme environments, such as space and nuclear applications. In this work, we explore both IJP and AJP of sensors for applications in human performance monitoring onboard the International Space Station and field property measurements inside nuclear test reactors. We use IJP of custom graphene inks on flexible substrates to sense pH and electrolyte concentrations, with potential applications in flexible and wearable electronic sensors for real-time analysis of various biological functions. We also explore the utility of AJP in conjunction with commercial nanoparticle inks for temperature melt arrays for in-pile nuclear sensors capable of measuring peak temperatures achieved during long-term irradiation experiments. Our results highlight the importance of structure-property-processing correlations in additively manufactured sensors to their performance in relative extreme environments.