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Accelerator-based tests of radiation shielding properties of materials used in human space infrastructures.

Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their known ability to protect human space infrastructures from meteoroids and debris. We measured the response to simulated heavy-ion cosmic radiation of these shielding materials and compared it to polyethylene, Lucite (PMMA), and aluminum. As proxy to galactic nuclei we used 1 GeV n−1 iron or titanium ions. Both physics and biology tests were performed. The results show that Kevlar, which is rich in carbon atoms (about 50% in number), is an excellent space radiation shielding material. Physics tests show that its effectiveness is close (80–90%) to that of polyethylene, and biology data suggest that it can reduce the chromosomal damage more efficiently than PMMA. Nextel is less efficient as a radiation shield, and the expected reduction on dose is roughly half that provided by the same mass of polyethylene. Both Kevlar and Nextel are more effective than aluminum in the attenuation of heavy-ion dose.

Impact of Spacecraft-Shell Composition on 1 GeV/Nucleon

Through the use of experimental data and Monte Carlo simulations we investigate the shielding properties of spacecraft-shell compositions exposed to 1 GeV/nucleon 56Fe ions, representative of the worst part of the Galactic Cosmic Ray (GCR) spectrum. Through the use of the Geant4 Radiation Analysis for Space (GRAS) tool, the dose reduction and the 56Fe-fragmentation induced by those structures currently used to protect part of the International Space Station (ISS) or designed for future inflatable habitats, are analyzed. The possible effects on spacecraft electronics are discussed.

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Abstract The Bioregenerative Life Support program CAB (Controllo Ambientale Biorigenerativo) is a key element of the Italian Space Agency (ASI) Medicine & Biotechnology scientific program, set forth in the ASI Activity Plan 2006–2008. The CAB program started in October 2006, under the prime partnership of Thales Alenia Space Italia, with a feasibility study of a controlled biological system, allowing the regeneration of resources and the production of food for life support in long duration missions. Main constituents of the CAB program are: (a) Higher plants as basic elements for food and oxygen production, CO2 regeneration and water purification via the photosynthetic and leaf transpiration processes, and (b) biological & physico-chemical systems for environmental control, monitoring, power & data distribution, etc. The sectors of technological and scientific concern are practically all the ones typical for life support systems in the frame of long duration human missions; i.e., food production, in particular via the cultivation of higher plants, and food management; air regeneration (production of O2, removal of CO2, trace gas control); water regeneration (urine processing, gray water processing, potable water management); solid waste processing; resources allocation and storage; control of environmental conditions (Thermal-hygrometric, light, pressure, radiation, etc).

Fe Ion-Fragmentation and Dose Reduction

A key function required of any infrastructure to support people in space for a considerable time is the ability to reproduce, as far as possible, the Earth’s natural ecosystem, aiming at the “closure” of the air, water and food cycles in a so-called Closed Ecological Life-support System (CELSS). The higher plant compartment is the largest element in a CELSS.

Plant bioregenerative life supports: The Italian CAB Project

Potable water is undoubtedly one of the most critical resources for the International Space Station (ISS) crews. The amount and quality of this resource, mainly provided to the ISS by the Space Shuttle and Progress, and in the near future by logistic vehicles Automated Transport Vehicle (ATV) and HTV, must be compatible with the crew consumption needs and health-related requirements. For this purpose, potable water must satisfy very stringent quality requirements from chemical and bacteriological point of view. The definition of such requirements, resulting from medical studies, lessons learned, technical constraints, is reached in agreement among ISS International Partners. Two different quality standards are defined, one for the ISS Russian Segment, the other for the US Segment and other International Partners. The ATV, a program under European Space Agency (ESA) contract and EADS Space Transportation (EST) prime contractor-ship, is the only logistic vehicle requested to transport and deliver potable water to ISS according to both quality standards. Significant efforts have been spent in Alenia Spazio, responsible for the ATV Integrated Cargo Carrier, to define all the activities necessary to accomplish this task. The main aspects under consideration have been: selection of materials in contact with water, identification of suitable potable water sources, water preparation and disinfection, and pre-conditioning of equipment. This paper focuses on preparation and quality of potable water as obtained in dedicated ground facilities. The quality and stability of source water are an essential pre-requisite to attain the required standards. Disinfection techniques using colloidal silver and iodine are discussed, and their implementation in the ATV Water Preparation Facility at Societa Metropolitana Acque Torino (SMAT) premises is presented. The results of chemical and micro-biological analyses performed on potable water batches treated with the defined techniques show that the requirements are fully satisfied.

Greenhouse: A Strategic Element to Support Humans in Space

Detection and identification of surface molecular contamination is important for improving process and product yields in a wide range of industrial applications. In particular, molecular compounds can easily deposit on the surface of hardware, optical components, semiconductor devices, medical devices, etc. with the risk of impairing their functionality. In this work, qualitative and quantitative metrological methodologies for surface molecular contamination detection based on Fourier transform infrared spectroscopy and micro-Raman spectroscopy are presented. The specificity of detection of two ubiquitous industrial contaminants i.e. poly(methylphenylsiloxane) and paraffin oil by infrared and Raman fingerprints is first demonstrated. Moreover, in order to obtain homogeneously contaminated surfaces that can be used as standard materials for Raman calibration, films of different thicknesses of contaminants were prepared on calcium fluoride windows, within a contamination range of 70–900 ng cm−2, by a spin coating method. The amount of contaminants spread on the surface was quantified by applying a pre-set FT-IR calibration curve in accordance with the European Cooperation for Space Standardization procedure (ECSS-Q-ST-70-05C) and it was subsequently used to calibrate the Raman equipment which demonstrated a sensitivity up to 10−8 g cm−2. A real case study of industrial contaminated surfaces i.e. a glass lens for a laser cutting machine is also presented to assess the applicability of both techniques in molecular contamination monitoring. In the discussed case Raman analysis turned out to be particularly useful for punctual investigation of the surface, especially when the sample is not transparent to the infrared radiation.

Quality of ATV Potable Water for ISS Crew Consumption

Bio-regenerative Life Support Systems (BLSS) uses biological processes to support an astronaut crew, and includes atmosphere revitalization, water recycling, food production, and organic waste recycling. The University of Arizona Controlled Environment Agriculture Center (UA-CEAC), Systems and Industrial Engineering Department, Sadler Machine Co. (USA) and Italian collaborators, Thales Alenia Space Italia (TAS-I), Aero-Sekur, SpA, and University of Naples Federico II are developing BLSS for future Lunar/Mars surface missions. Current efforts at UA-CEAC include operation of four BLSS Lunar Greenhouse (LGH) Prototype Units with the primary purpose of demonstrating poly-culture production of food crops in a semi-closed gaseous cycle, and preliminary efforts of waste DWEComposting, Solar Concentrating Plant Lighting/Power System, and System Monitoring/Telepresence Support. TAS-I, the University of Naples, and Aero-Sekur BLSS efforts in Italy include operation of Recyclab, the EDEN chamber, and the development of space plant growth chambers. UA-CEAC efforts are supported by NASA Ralph Steckler Phase II Space Grant while the Italian collaborators have been supported by ESA, ASI, and regional, and internal sources. Based on NASA crop production area estimates the LGH with its four modules will support a four person crew with 100% of their water/atmosphere

Direct detection and quantification of molecular surface contaminants by infrared and Raman spectroscopy

With concurrent interests on Bio-regenerative Life Support Systems (BLSS), Italian and USA industrial and academic institutions, including Thales Alenia Spac e Italia (TAS-I), the University of Arizona (UA) an d the Sadler Machine Company have teamed in a collaboration effort. The collaboration has been providing personnel exchanges, sharing accumulated experiences and complementary competencies to establish synergies in the multi-dis ciplinary field of BLSS. The initial phase has linked aerosp ace engineering and system design competences together with other professional fields of plant sciences, controlled e nvironment production systems, mathematical modeling and computational analysis. The overriding theme of our activities is the succe ssful crop production, with effective resources uti lization, such that sufficient edible biomass will be continu ously provided to supply the desired percentage of the crew food calories from the system. The focus is mainly with crops targeted for space such as lettuce, sweet pot ato and tomato. Using available data and existing models, crop prod uction studies have been designed and implemented to achieve production results within a semi-closed structure t hat will be useful for correlation studies, as well as for strengthening the experiences with an operational p rototype BLSS. While the EDEN controlled plant growth chamber sited at TAS-I Recyclab has been operated to focus TAS-I engineers attention on the critical physical and biological aspects on a small scale demonstrator, the 22 m 3 Lunar Greenhouse (LGH) Prototype, sited at the Controlled Environment Agriculture Center (CEAC) at the University of Arizona (UA), has been upgraded and prepared for 9months of extensive utilization, supported by the N ASA Steckler Space Grant (Phase 1, January ‐ October 2010). Data will be evaluated within a TAS-I implemented model for the plant-life-support element, based on t he NASA Modified Energy Cascade (MEC) Model for Crop Growth 19,21 . Testing is in progress and data acquisition, management, utilization and improvements of the models will be completed. The subsequent system simul ations will be used for developing future designs of such facil ities. This paper describes the collaboration, focusing on the available facilities improvement, the definiti on of the data gathering, storage and elaboration strategies, the discussion of the preliminary results achieved and the illustration of the forthcoming activities.

Bio-Regenerative Life Support System Development for Lunar/Mars Habitats

Onboard the International Space Station (ISS), water is well known to be an essential resource for life support: purification and recycling water systems are used to minimize its consumption. Nevertheless, it is necessary to provide periodically additional water through logistical support missions. With the dismissal of the Shuttle, procurement of equipment and supplies was delegated to the pressurized cargo modules, which transport rigid or flexible containers filled with potable water for crew consumer. This work shows the preliminary study results focused on the realization of flexible bags which can operate in commercial space missions for different operative scenarios. In one case the described bags would supply the two potable water qualities coexisting on the ISS with different bactericidal agents (iodine and silver for respectively American and Russian waters) and once drained they could be refilled or contain other fluids (e.g. waste water). The bags are foreseen to be collocated and transported inside modified Cargo Transportation Bags, starting from what already designed for the Cygnus commercial cargo, but adapted to the different needs. In addition, this paper briefly reports the related contribute to the study of the Reconfigurable Cargo Transportation Bags under development at NASA Ames.

Evaluation of Bio-regenerative Life Support Systems in the frame of a Concurrent International Cooperation

2. Moreover, in order to complete the investigation several batches of latent condensate have been produced in the RecycLAB laboratory. The wastewaters ersatz were obtained adding the needed chemical reagents in demineralized water according to the BVAD 2 recipe. In order to investigate the efficiency of the water treatment and revitalization via multi-filtration and membranes technology, a demonstrator has been designed, developed and acquired. The facility provides a pre-treatment unit (activated carbon, ion exchange resins, and filtration modules), an ultra-filtration ceramic module, two reverse osmosis modules, an UV-light disinfection and a post treatment module (active carbon, ion exchange resins). In order to minimize the consumables replacement, it has been verified that it is possible to regenerate latent condensate wastewater using only the reverse osmosis treatment stage. Chemical and physical properties of the regenerated water were found to be similar to demineralized water ones except for the TOC value.