Modeling and experimental evaluation of membrane distillation aimed at urine treatment for direct potable reuse in space stations

Improving wastewater reuse systems represents a game changer for the economy of space exploration activities. The goal of this research is to evaluate direct contact membrane distillation for the treatment of urine aimed at direct potable reuse in space stations. A transient, 2-D model able to predict the membrane distillation system behavior under different operating conditions is developed. The model is validated by experimental tests conducted with a synthetic urine-like feed solution, considering both productivity and final water quality. The water flux and quality analyses imply high rejection of soluble salts and organics. However, direct water reuse may be compromised by the ammonia passage. A sensitivity analysis is thus performed to investigate the effects of feed pH, temperature, and cross-flow velocity on water flux and ammonia passage. The system shows the capability of treating 8 L of urine up to 90–95 % recovery rate, during 10 h of daily operation at 40 °C feed and 20 °C distillate inlet temperatures. This amount is sufficient to satisfy four crew members while meeting high system compactness. Concurrently, the ammonia passage may be limited by lowering the feed pH, thus easing the post-treatment steps necessary for safe direct reuse

The preliminary design of the EDEN ISS Mobile Test Facility - An Antarctic greenhouse

EDEN ISS is a European project to investigate cultivation techniques of plants in space for future bio-regenerative life support systems. The technologies will be tested in a laboratory environment as well as at the highly-isolated German Antarctic Neumayer Station III. A small and mobile container-sized test facility will be built in order to provide realistic mass flow relationships. This paper provides a summary of the activities performed in the early design phase of the project. The design phase started with the kick-off meeting in March 2015 and focused on the requirements definition and design of the greenhouse. The EDEN ISS partners met for a design workshop from September 7th to September 18th, 2015 in the Concurrent Engineering Facility of DLR’s Institute of Space Systems in Bremen, Germany. The purpose of the workshop was the generation of a preliminary design for the Mobile Test Facility. The Mobile Test Facility will be built later in the project and used to conduct an over one year long experiment campaign beginning in December 2017 in Antarctica. During the two week workshop, the consortium members worked on their respective subsystems and on how their systems can be integrated in the overall greenhouse. The design of each subsystem was greatly improved. System budgets (e.g. mass, power) were calculated, engineering drawings created and estimates with respect to inputs and outputs made. A very important step was the consolidation of the system and subsystem requirements. This paper summarizes the results of the design work-shop and describes the preliminary design of the EDEN ISS Mobile Test Facility

Introducing EDEN ISS - A European project on advancing plant cultivation technologies and operations

Plant cultivation in large-scale closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The EDEN ISS project foresees development and demonstration of higher plant cultivation technologies, suitable for future deployment on the International Space Station and from a long-term perspective, within Moon and Mars habitats. The EDEN ISS consortium will design and test essential plant cultivation technologies using an International Standard Payload Rack form factor cultivation system for potential testing on-board the International Space Station. Furthermore, a Future Exploration Greenhouse will be designed with respect to future planetary bio-regenerative life support system deployments. The technologies will be tested in a laboratory environment as well as at the highly-isolated German Antarctic Neumayer Station III. A small and mobile container-sized test facility will be built in order to provide realistic mass flow relationships. In addition to technology development and validation, food safety and plant handling procedures will be developed. This paper describes the goals and objectives of EDEN ISS and the different project phases and milestones. Furthermore, the project consortium will be introduced and the role of each partner within the project is explained

SCALISS: A European tool for automated SCAling of LIfe Support Systems

Designing the Environmental Control and Life Support System (ECLSS) for exploration missions to the interplanetary space is a complex task beginning from the definition of the needs (e.g. diet, safety, radiation level,..) up to the selection of technology possibilities. In this context a major issue is the influence of crew number and mission duration to the ECLSS design. These are the main reasons why during mission studies the design of the ECLSS system mostly starts from scratch. Uncertainties about requirements, functions and technologies most suitable for the mission lead to a high number of iterations before a baseline design can be achieved. The aim of the SCALISS (Scaling of Life Support Systems) study was to understand and investigate in ECLSS functionality, technologies and scalabilities in order to produce a robust initial design starting point for future Phase-A studies with an automated tool. The developed Java-based ECLSS sizing tool is described in this paper together with the validation case study results. The possible evolutions and interactions with the ALiSSE tool are also described

Main performance results of the EDEN ISS rack-like plant growth facility

Plant cultivation in large-scale closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The Horizon2020 EDEN ISS project aims at development and demonstration of higher plant cultivation technologies, suitable for near term deployment on the International Space Station (ISS) and from a long-term perspective, within Moon and Mars habitats. The EDEN ISS consortium, as part of the performed activities, has designed and built a plant cultivation system to have form, fit and function of an European Drawer Rack 2 (EDR II) payload, with a modularity that would allow its incremental installation in the ISS homonymous rack, occupying from one-quarter rack to the full system. The construction phase is completed, and the developed system is being tested in a laboratory environment, planned for further validation at the highly-isolated German Antarctic Neumayer Station III, in a container-sized test facility to provide realistic mass flow relationships and interaction with a crewed environment. This paper describes the system as built and the key results of the first ISPR plant growth facility laboratory tests

Status of the EDEN ISS Rack-like food production unit after five months in Antarctica

Plant cultivation in large-scale closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The Horizon2020 EDEN ISS project aims at development and demonstration of higher plant cultivation technologies, suitable for near term deployment on the International Space Station (ISS) and from a long-term perspective, within Moon and Mars habitats. The EDEN ISS consortium, as part of the performed activities, has designed and built a plant cultivation system to have form, fit and function of an European Drawer Rack 2 (EDR II) payload, with a modularity that would allow its incremental installation in the ISS homonymous rack, occupying from one-quarter rack to the full system. The developed system has been completed and tested in a laboratory environment in early 2017. The system was then integrated and tested at DLR Bremen into the main transport container (MTF). In the last 5 months the system was operated also in the highly-isolated German Antarctic Neumayer Station III, in the container-sized test facility to provide realistic mass flow relationships and interaction with a crewed environment. This paper describes the key results of the Bremen test phase as well as initial ISPR plant growth facility tests in Antarctica as space-analogue environment

EDEN ISS Rack-like food production unit: results after mission in Antarctica

Plant cultivation in large-scale closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The Horizon2020 EDEN ISS project aims at development and demonstration of higher plant cultivation technologies, suitable for near term deployment on the International Space Station (ISS) and, in a longer term perspective, within Moon and Mars habitats. The EDEN ISS consortium, as part of the performed activities, has designed and built a plant cultivation system having form, fit and function of a European Drawer Rack 2 (EDR II) payload, with a modularity that would allow its incremental installation in the ISS homonymous rack, occupying from one-quarter rack to the full system. The developed system, named RUCOLA (Rack-like Unit for Consistent on-orbit Leafy crops Availability) was completed and tested in a laboratory environment in early 2017. The system was then operated in the highly-isolated German Antarctic Neumayer Station III, in a container-sized test facility to provide realistic mass flow relationships and interaction with a crewed environment. This paper describes the key results of the RUCOLA plant growth facility tests in Antarctica as a space-analogue environment

The EDEN ISS Rack-Like Plant Growth Facility

Plant cultivation in large-scale closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The Horizon2020 EDEN ISS project aims at development and demonstration of higher plant cultivation technologies, suitable for near term deployment on the International Space Station (ISS) and from a long-term perspective, within Moon and Mars habitats. The EDEN ISS consortium, as part of the performed activities, has designed a plant cultivation system to have form, fit and function of an European Drawer Rack 2 (EDR II) payload, with a modularity that would allow its incremental installation in the ISS homonimous rack, occupying from one-quarter rack to the full system. The construction phase is started, and the developed system will be tested in a laboratory environment as well as at the highly-isolated German Antarctic Neumayer Station III, in a container-sized test facility to provide realistic mass flow relationships and interaction with a crewed environment. This paper describes the goals and system general design status of EDEN ISS ISPR plant growth facility

Overview of the EDEN ISS Project. Mobile Test Facility: Analogue Testing of Plant Cultivation

Plant cultivation in closed environments is challenging and several key technologies necessary for space-based plant production are not yet space-qualified or remain in early stages of development. The European-funded Horizon H2020 EDEN ISS project has the goal to develop and demonstrate higher plant cultivation technologies and procedures, suitable for future deployment on the International Space Station and from a long-term perspective, within Moon and Mars habitats. Over the last four years, the EDEN ISS consortium designed and tested essential plant cultivation technologies using an International Standard Payload Rack cultivation system for potential testing on-board the International Space Station. Furthermore, a Future Exploration Greenhouse was designed with the focus on future planetary bio-regenerative life support system deployments. A dedicated greenhouse system, called the Mobile Test Facility, was designed, built and deployed to the German Neumayer III research station in Antarctica. In Addition to producing biomass that will be returned to partner laboratories for analysis the facility provides the overwintering crew of 10 people with fresh vegetables during their isolation phase. The presentation gives an overview of the EDEN ISS research objectives, associated milestones and reports on the status of the analogue mission in Antarctica. In addition, the designed and implemented subsystems are described. Further, an overview of the assembly, integration, and test phase that took place in 2017 at the DLR Institute of Space Systems is given