This project supports the development and delivery of the Exploration Toilet Dose Pump (ETDP), the first hardware element for an exploration-class waste management system. The flight demonstration will take place on the International Space Station (ISS), where our team will deliver two flight-ready Dosing Assemblies and two auxiliary Dose Pump Controllers (Flight and Flight Spare). MSFC will develop and test all other associated hardware, including a Development UWMS Controller, an EDU auxiliary Dose Pump Controller, and one EDU Dosing Assembly. The Dosing Assembly, consisting of the ETDP and conductivity sensor, is designed to integrate directly into the existing UWMS enclosure and control system on ISS, requiring no modifications to ISS or UWMS hardware. The ETDP will operate as a drop-in replacement for the Collins Aerospace Dose Pump, utilizing the same physical interfaces and solenoid valve signaling to ensure full compatibility. The Development UWMS Controller will emulate the existing Collins UWMS Controller to support integrated hardware and software development and test activities. The auxiliary Dose Pump Controller will interface with the Collins Controller to operate the ETDP and conductivity sensor. Cable designs will support interfaces between the Dose Pump Controller and the Collins Controller, ISS LAN, ISS 28V power, and the ETDP itself. The effort also includes definition of controller requirements, command and telemetry content, and software design inputs to support development of application layer software.

All design, integration, and verification testing will be conducted at MSFC, leveraging its ECLSS Development & Test Facilities, Fluid Systems Test Labs, and Materials & Manufacturing Facilities. The ET Dose Pump will undergo functional, proof and leak, vibration, thermal cycle, EMI, acoustic, and Human Factors Integration Testing (HFIT) to meet SSP 57000 requirements. Once qualified, the flight units will be pre-filled with Pretreat-lite and shipped to CMC for integration before launch.

On orbit, the ISS crew will install the ETDP, which will autonomously respond to UWMS Controller signals for dosing operations, matching Collins Dose Pump flow rates to maintain operational consistency. The ETDP Controller will provide on-orbit tuning capability, system protections (e.g., over-temperature shutoff, current fault detection), and telemetry monitoring, with data routed to the UWMS Controller for analysis. The Dose Pump will not create backpressure on the Alternate Pretreat Concentrate (APC) tank, ensuring safe operation in microgravity.

Successful demonstration of the ET Dose Pump on ISS will provide valuable reliability data for the ETDP and enable continued operation of the UWMS, which is critical for supporting Orion system testing. While the Orion vehicle does not require the dose pump itself, its operation on the ISS contributes to reducing risk for Artemis missions by validating UWMS performance in a relevant environment. Lessons learned will be systematically documented to support future technology assessments and mission planning.