Overview of the Space Toilet History

One of the most critical parameters of life support for receiving, storing, and disposing of human waste has been provided throughout the history of manned spaceflight by the development and application of a wide variety of toilet systems, ranging from disposable equipment in short-term spaceflights to complex systems with waste pre-treatment as part of the regeneration complex of orbital stations. The history of space toilet development and application from 1961 to the present is part of the history of life support system development, including the vast experience of successful solutions, elimination of errors and shortcomings, and development along with improvements in space technology. Knowledge of this history is useful to design engineers, operations engineers, and astronauts, and is critical to the successful design of toilet systems for new space missions. The paper provides an overview of space toilet means and systems, their design and operational history from the first manned missions, the Apollo and Soyuz spacecraft, the Skylab, Salyut and MIR orbital stations, the Space Shuttle and Crew Dragon spacecraft, to the ISS. The paper also provides a comparative analysis of the principle schemes, designs, and technologies used for urine and feces collection, urine separation, storage and pre-treatment, and waste disposal. Specific features of in-flight operation of space toilets from the point of view of reliability and comfort are considered separately, examples from the history of failures of in-flight toilets and their elimination are given, with conclusions on the results of operation on the directions of further improvement of such systems.