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Hybrid peening is proposed to be applied with objective of improving gears fatigue life with low impact on part manufacturing time. This process consists of an alternative of a conventional dual peening, but with mixing two different media classes in only one stage. A procedure to define media classes’ selection as well as mix distribution is proposed considering the objective of enhancing part lifetime, background of gear failure modes and residual stress theory, by using known residual stress profile prediction models. Results showed that it was possible to reach maximum compressive residual stress target, without being far from its depth desired.

Among the different freezers needed for preservation of samples produced in the ISS with the various life science programs (e.g., biotechnology cell science, gravitational biology, ecology, … ), the Minus Eighty degrees Celsius Laboratory Freezer for the ISS, MELFI, will be the first freezer to be delivered to NASA as Laboratory Support Equipment (LSE) by the European Space Agency (ESA). From the beginning, the technology for a −80°C freezer was identified as very critical to develop. Throughout the design and development phases, the different technologies were improved and secured to have a freezer in time for the Space Station Utilization Flights. This paper will start with a system overview, showing the main features of MELFI. The different technical challenges will be then explained and the design choices highlighted. Details on the qualification program will show how those challenges are overcome.

The Minus Eighty (Degrees Celsius) Laboratory Freezer for the International Space Station (MELFI) is one of the freezers developed by ESA on behalf of NASA. Peculiar requirements for that facility are the long-term storage at low temperature, the rapid freezing of specimen to the required temperature, the large cold volume (300 l) and the low power consumption. To verify those requirements before the manufacturing of the flight hardware, a dedicated test campaign was performed on a ground model. This paper will start with a system overview, showing the main features of MELFI. The test set-up as well as their results will be presented and discussed, with particular emphasis on the methods used to predict the on-orbit (0-gravity) behaviour, by avoiding the sample internal convection and dewar internal convection during the test execution.

The Minus Eighty degrees Celsius Laboratory Freezer for ISS (MELFI) will be the first freezer to be delivered to NASA as Laboratory Support Equipment (LSE) by ESA. Among the MELFI thermal requirements, the rapid freezing of samples to a required temperature and the low power consumption that limits MELFI performance during re-cooling phases after power off, are ones of the most critical. This paper will present the thermal activities, which led both to a verification of those requirements and to a complete thermal characterization of MELFI.

The Minus Eighty degrees Celsius Laboratory Freezer for ISS (MELFI) is a freezer that will be delivered to NASA as Laboratory Support Equipment (LSE) by ESA. A first qualification test campaign was conducted with the DM (Development Model) Brayton Sub-System (BSS) installed in MELFI QM (Qualification Model) rack. This test campaign gave a lot of information on MELFI thermal system behaviour. Nevertheless, the lessons learned from these first performance tests raised questions about the tests to be performed with MELFI first flight model. Thus, this paper will present the qualification test results, the observations made after these tests and, in the light of these remarks, the logic followed to completely redefine the thermal test plan in order to fully cover the verification of the thermal requirements before MELFI first flight.

A new software tool, MELISSA, has been developed for the simulation of life-support systems and other network-type subsystems. MELISSA features an intuitive graphical modeling environment and interactive simulation execution. Applications of MELISSA range from the analysis and validation of new ECLSS designs, to parametric optimization studies, to failure mode effects and criticality analysis of life-support systems. Additionally, MELISSA can be employed for training ECLSS developers and users, and as a teaching tool for lectures and seminars on systems design. As a demonstration, an ECLSS similar to the one of the International Space Station has been modeled and simulated.

When a balanced diet of a crew is supposed to come from a biogenerative life support system (BLSS), such as MELISSA, it is necessary to conceive a “food management” system in order to match the food production capability of the LSS to the needs of the crew. The objective of this work is the development of a database including crew constraints, food production and preparation constraints, BLSS constraints (mass, crew time, energy consumption) as well as the nutritional data on food and dishes, with the aim to elaborate a selection of possible menus and recipes which satisfy nutritional requirements and acceptability over a long period for a crew. The database is managed by a web client interface developed in PHP, and the whole was called “MELiSSA Food Database” as MELiSSA was used to define the food production (i.e plants) capability of the BLSS.

MELiSSA is a micro-organism based ecosystem conceived as a tool for understanding the behaviour of artificial ecosystems and developing the technology for a future biological life support system for long term manned space missions. The driving element of MELiSSA is the recovering of oxygen and edible biomass from waste generated by the crew (CO2, faeces, urea). MELISSA is composed of four microbial compartments. A fifth compartment, a higher plant chamber (HPC), working in parallel with the Spirulina compartment was associated to the MELiSSA loop in order to improve the diet quality for the crew.

Initiated in March 1989, the MELISSA (Micro-Ecological Life Support Alternative) has been conceived as a micro-organisms and higher plants based ecosystem intended as a tool to gain understanding of the behaviour of artificial ecosystems, and for the development of the technology for a future biological life support system for long term manned space missions, e.g. a lunar base or a mission to Mars. The collaboration was established through a Memorandum of Understanding and is managed by ESA/ESTEC. It involves several independent organisations: IBP Orsay (F), University of Ghent (B), University of Clermont Ferrand (F), VITO Mol (B), ADERSA (F), University “Autonoma” of Barcelona (E), University of Guelph (CND). It is co-funded by ESA, the MELISSA partners, the Spanish (CIRIT and CICYT) and Canadian (CRESTech) authorities. The driving element of MELISSA is the recovering of edible biomass from waste (faeces, urea), carbon dioxide and minerals.

The MELiSSA (Microbial Ecological Life Support System Alternative) project was designed as an early model of a future artificial ecosystem for long-term space missions. It centres on the recovery of edible biomass from waste, CO2 and minerals, with direct use of light as a source of energy for photosynthesis. MELiSSA is composed of four axenic compartments colonized by microorganisms, and a fifth compartment formed by the crew on board the craft. Simulation of the entire MELiSSA loop had been performed to obtain mass fluxes and concentrations of microorganisms, and liquid and gas components in all the system streams. This first approach helped to define the process conditions necessary to obtain complete recycling of nitrogen or regeneration of the atmosphere. This paper reports on the simulation of the behaviour of the loop when the photosynthetic compartment is working under various light-limiting conditions.

The MELISSA (Microbial Ecological LIfe Support System Alternative) project has been set up to be a model for the studies on ecological life support systems for long term space missions. The compartmentalisation of the loop, the choice of the micro-organisms and the axenic conditions have been selected in order to simplify the behaviour of this artificial ecosystem and allow a deterministic and engineering approach. In this framework the MELISSA project has now been running since beginning 1989. In this paper we present the general approach of the study, the scientific results obtained on each independent compartment (mass balance, growth kinetics, limitations, compound conversions,..), the tests of toxicity already performed between some compartments and their effect on the growth kinetics. The technical results on instrumentation and control aspects, and the current status of the ESA/ESTEC hardware are also reviewed.

The MELISSA (Micro-Ecological Life Support Alternative) project was initiated in 1989. The recycling system is conceived as a micro-organisms and higher plants based ecosystem. As a matter of fact, it is intended as a tool to gain understanding of closed life support, as well as the development of the technology for a future life support system for long term manned space missions, e.g. a lunar base or a mission to Mars. The collaboration was established through a Memorandum of Understanding and is managed by ESA. It involves several independent organisations: University of Ghent, EPAS, SCK, VITO (B), University of Clermont Ferrand, SHERPA (F), University “Autonoma” of Barcelona (E), University of Guelph (CND). It is co-funded by ESA, the MELISSA partners, the Belgian (DWTC), the Spanish (CIRIT and CICYT) and Canadian (CRESTech, CSA) authorities. The driving element of MELISSA is the production of food water and oxygen from organic waste (inedible biomass, CO2, faeces, urea).

This paper introduces two modeling approaches in consideration for the MELiSSA Higher Plants Compartment. This includes an empirical light response curve modeling approach and the Modified Energy Cascade (MEC) model. The MEC model was translated into EcosimPro and evaluated for its performance under a range of environment conditions. The model demonstrated an adequate response to changes on the environmental conditions (temperature, CO2 concentration and light flux) predicting the gas exchange (O2 production, CO2 consumptions, and water vapor transpiration)

The transport of goods and people by sea, today, must meet the need to reduce the consumption of fuel oil. In addition, it has to ensure operational reliability and vessel availability, to reduce maintenance costs and comply with emission legislation. To this end, it is necessary to apply a marine engine combustion control system already widely used in engines for land transport. This will allow the ship's engines to operate reliably and in compliance with the best performance for which it was designed. The combustion control could also ensure a more balanced operation of the cylinders and reduce the torsional vibrations of the entire engine, as well as the management of the engine according to the adopted fuel: diesel, dual fuel, methanol, ammonia. Generally, the control of combustion in engines is carried out through the use of pressure sensors that face directly into the combustion chamber.

Oscillators are key components in automotive electronics systems. For example, a typical automotive camera module may have three or more oscillators, providing the clocks for microcontrollers, Ethernet controllers, and video chipsets. These oscillators have historically been built around a quartz crystal resonator connected to an analog sustaining circuit driving the crystal to vibrate at its resonant frequency. However, quartz-based devices suffer from poor performance and reliability in harsh automotive environments. SiTime has developed timing solutions based on silicon micro-electromechanical systems (MEMS) technology that exhibit better electromagnetic noise rejection and better performance under shock and vibration. In this paper, we first discuss the design and manufacturing of the MEMS-based device, with emphasis on the specific design aspects that improve reliability and resilience in harsh automotive environments.