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Christopher Zahner

Publications and source records attributed to Christopher Zahner.

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Operation of the Urine Collection and Pretreatment System in the ISS US Segment Waste & Hygiene Compartment (WHC)

The US Segment Waste & Hygiene Compartment (WHC)provides the capability to collect crew urine for subsequent delivery to the Urine Processor Assembly (UPA). Urine collection in the WHC is accomplished with the urine collection and pretreatment system designed by RSC “Energia” and NIICHIMMASH and integrated into the WHC by Boeing and NASA. The WHC was installed in the US Laboratory Module in November 2008 and later transferred to the Node 3 in February 2010.As of February 1st 2021, the WHC has collected 25855 liters of pretreated urine. The system collects urine from astronauts, adds required pretreatment chemicals to maintain chemical and microbial control of the urine, and delivers the pretreated urine to the Urine Processor Assembly. This paper will summarize the twelve years of operation of the WHC on ISS, significant anomalies, and lessons learned from its operation.

D Layne Carter↗
NASA NTRSDate not supplied

Developing Mission Segment-Specific Clinical Data for Impact

Space exploration missions represent a significant future objective for NASA’s human spaceflight operations for the near and long term. By operating missions during longer periods and over further distances, NASA’s mission planning models, hardware systems, and medical capabilities will be stretched beyond their original design constraints. The necessity of medical training and medical supply manifesting for such missions is likely to become incredibly intricate as trade-space analysis is performed over varying mission profiles. For this purpose, IMPACT was created to extend and improve the Integrated Medical Model (IMM) which is used for International Space Station (ISS) medical predications and consists of a probabilistic risk assessment tool that simulates missions to calculate risks given the constraints on crew complement, mission duration and activity (such as Extravehicular Activities), power, communication, mass, volume, and evacuation consideration as well as to predict mission outcomes. Currently, the medical evidence used to support IMPACT remains static, addressing risks of a medical condition and the impacts of the condition during spaceflight only, but is only calculated for a small number of mission parameters. Extended missions will consist of new and varied living environments, changing gravitational loads, and dynamic working requirements. Medical risks are not typically constant but will change depending upon the physical and physiological environment of the body during all phases of a mission. Risks are likely to shift during different mission segments, and understanding how components of a mission profile change risks will assist mission planners to increase chances for mission success.

Christopher Zahner↗