Urine Monitoring System


Overview | Description | Applications | Operations | Results | Publications | Imagery

Facility Overview

This content was provided by Mark S. Clarke, Ph.D., and is maintained in a database by the ISS Program Science Office.

Brief Facility Summary

The Urine Monitoring System (UMS) is a system designed to collect an individual crewmember's urine void, gently separate liquid from air in that void, accurately measure the liquid volume of the urine, allow for void sample acquisition, and to then discharge the remaining urine into the Waste and Hygiene Compartment (WHC) on board the International Space Station.

Facility Manager(s)

  • Mark S. Clarke, Ph.D., University of Houston/JSC Space Center, Houston, TX, United States
  • Co-Facility Manager(s)

    Information Pending

    Facility Developer(s)

    Johnson Space Center, Human Research Program, Houston, TX, United States

    Sponsoring Agency

    National Aeronautics and Space Administration (NASA)

    Expeditions Assigned


    Previous ISS Missions

    The UMS is a successor design to the existing Space Shuttle Urine Monitoring System, which flew on seven Shuttle flights after its initial development in 1979.

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    Facility Description

    Facility Overview

    • The Urine Monitoring System (UMS) is a successor design to the existing Space Shuttle system and will resolve anomalies such as: liquid carry-over, inaccurate void volume measurements, and cross contamination between void samples.

    • During Increment 29/30, the crew will perform a functional validation.

    • Following successful completion of the functional validation, the UMS will replace Urine Collection Devices as the primary means of urine sample collection to provide PIís with experimental data.

    • In the future, the UMS may be used to facilitate non-invasive methods for monitoring crew health, evaluation of countermeasures, and implementation of a variety of biomedical research protocols on future exploration missions.


    The International Space Station (ISS) Urine Monitoring System (UMS) is an upgrade to the previous Space Shuttle system. The UMS is capable of collecting and accurately measuring void volume, separating urine from air in the void, and allowing acquisition of individual, uncontaminated urine samples from ISS crewmembers, with samples being collected using frozen urine syringes and/or ambient preserved urine syringes containing a mixture of thymol and thimerosal. The UMS is designed to operate in conjunction with the airflow of the Waste and Hygiene Compartment (WHC) of the ISS; the hardware consists of a laptop computer and a mechanical module. The laptop serves as the primary crew interface, while the mechanical module contains a liquid/air separator, a motor, solenoid valves, fluid plumbing and the sample acquisition port. While deployed, the mechanical module resides in the Waste and Hygiene Compartment in Node 3 of the ISS.

    A safe, accurate and reliable means of obtaining representative urine samples and total void volume measurements from the ISS crewmembers is essential to human research. Use of the UMS substantially reduces the launch mass and volume of consumables required for urine collection, eliminates the need for on-orbit stowage and disposal of large quantities of leftover urine, avoids the loss of urine to the water reclamation system when urine samples are required, resolves gender issues with the current system, and provides ease of operation.

    The UMS also facilitates the performance of future investigations requiring urine sample collection by automatically measuring void volumes which is required to enable future real-time analysis of samples. Operational deployment of the UMS will reduce the number of samples requiring return to Earth for analysis and provides more timely results to investigators along with feedback to medical personnel regarding crew health.

    During the equipment checkout, the UMS hardware is functionally tested to determine its efficacy at eliminating liquid carry-over between cycles, inaccurate void volume measurements, and cross contamination between void samples. Samples obtained as part of the checkout return aboard STS-134/ULF6 for postflight analysis. Once proper functioning is verified, the UMS will be available for use by experiments that require urine collection and determination of urine volume. Results concerning accurate void volume measurements will be quickly analyzed via downlink of log files. Once the volume accuracy is determined to be satisfactory, the UMS will be immediately available for use by experiments that require urine collection. Analysis of liquid carry-over and cross-contamination will be determined by ground analysis of samples returned from the checkout. Results of the ground analysis will be communicated to the PI teams already using UMS for sample collection for their information and evaluation.

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    Facility Operations

    The crew installs and activates the ISS UMS. One crewmember acts as both operator and subject to perform the following tasks:

    • Functional validation sequence is intended to validate accurate individual void volume measurements across a range of volumes and sample specific gravities. The operator injects each pre-filled validation syringe containing a non-toxic urine simulant or distilled water into the ISS UMS urinal hose, simulating various micturition (urination) volumes. Certain validation syringes are injected one per cycle and treated as single micturitions, while others are injected in sets per cycle. The operator also acquires samples for post-flight analysis to determine carryover volumes and cross-contamination. A total of 37 validation syringes are utilized for the evaluation. Two additional validation syringes are flown to serve as controls.

    • Nominal usage will begin after successful validation. For nominal use, the crew voids into the UMS which allows collection of urine samples for an experiment.

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    Results/More Information

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    Information Pending

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    Results Publications

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

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    Related Websites
  • ISS UMS GFE Website
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    image Computer generated depiction of the mechanical module portion of the Urine Monitoring System (UMS). Image courtesy of the Johnson Space Center, Human Research Program, Houston, TX
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    image Photograph of the mechanical module portion of the Urine Monitoring System (UMS). Image courtesy of the Johnson Space Center, Human Research Program, Houston, TX
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