Space Toilet Technologies and Their Applicability to Various Human Space Missions

Receipt and disposal of human waste, urine and feces, in space is provided by various waste management systems and disposal and sanitary devices, "space toilets" on space stations and vehicles. Several factors, such as microgravity, mission duration, life-support structure, and waste disposal or recycling capabilities, determine the choice of technologies and the design of space toilets. The paper analyzes space toilet technologies based on the experience of their development and operation on orbital stations and space vehicles for main functions. Various schemes of waste reception and separation, urine pretreatment and quality control of pretreatment, urine transfer for temporary storage or processing, variants of urine and solid waste tank designs are considered and their advantages and disadvantages are analyzed. Based on the results of the analysis, the paper gives recommendations for the choice of optimal technologies and types of space toilets design for space vehicles, orbital stations, landing modules and planetary surface stations.