Our methodology and our systemic and control models are used in the space industry sector through two projects mainly. These 2 major projects of the European and Canadian consortium led by the ESA (European Space Agency) are MELiSSA and ALISSE-MARS and both have been launched for scientific spatial missions . Sherpa Engineering participates to the consortium as modeling specialist.
ALISSE-MARS has the objective of developing a methodology and the necessary tools to compare and evaluate the human life related systems taking into account all possible criteria: mass, energy performance, matter transformation, power, reliability, crew risks, maintenance, operation and durability.
MELiSSA (Micro-Ecological Life Support System Alternative) is another ESA project that has the objective of building an artificial eco-system based on micro-organisms and plants to provide some technology needed for human life for long duration spatial missions. MELiSSA loop is in charge of revitalize breathing air, produce water and food from the crew’s organic wastes and released carbonic dioxide. This is possible thanks to a set of bacteria and plants treated by different processes to simulate in an artificial way the natural eco-system existing in a lake. More information about the MELiSSA project is available here :
ALISSE : Systemic modeling
The ALISSE program by the ESA (European Space Agency) is a representative example of a comprehensive systemic modeling project. We are in charge of the program management and the software platform development to allow all partners work together by using a model-based multi-view approach.
Our systemic modeling methodology lays on the General System Theory (GST) basis. This theory is well known and applies to many systems but is yet not widely used in the industrial sector. We are innovative because we use GST methodology to empower the design process globally and systemically.
MELiSSA : Control system design
From our deep knowledge on control systems, we have brought it to the spatial domain through our contribution to the MELiSSA program. This program is also led by the ESA and Sherpa Engineering is responsible for the hierarchical architecture of the control and its implementation in PLCs (Programmable Logic Controller).
Model-based predictive controls are essential and most relevant in this project due to its highest complexity. MELiSSA must provide answers to crew’s activity changes very quickly and consequently the control of the whole system must be extremely dynamic, robust and performing.
MELiSSA : Knowledge management
Another contribution of Sherpa Engineering to the MELiSSA program illustrates our competences in knowledge management. MELiSSA is very innovative as a concept and requires a high number of contributors. One of our roles in the project is to move from individual contributions to an fully organized and comprehensive program knowledge management.
During the program, lasting many years, there have been successive interactions of several aspects and the global competence framework has changed. We have been able to integrate evolutions of the project in our knowledge management program.