Analysis and simulation of a synergetic environmental control and life support system for long duration spaceflight
- Autores: Gisela Detrell Domingo
- Directores de la Tesis: Eulàlia Griful (dir. tes.), Ernst Messerschmid (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2015
- Idioma: inglés
- Tribunal Calificador de la Tesis: Ernst Messerschmid (presid.), Jasmina Casals-Terré (secret.), Stefanos Fasoulas (voc.)
- Programa de doctorado: Programa Oficial de Doctorado en Ingeniería Mecánica, Fluidos y Aeronáutica
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Manned missions carried out in the las t decades were either clos e to Earth or s hort m is s ions . In contras t, Space Agencies future plans include m anned exploration m is s ions to as teroids , the Moon and finally Mars . The expected m is s ion durations ris e s ignificantly and the greater dis tance from Earth m akes a res upply or res cue m is s ion alm os t im pos s ible. Thes e future plans m ake it neces s ary to develop a new Environm ental Control and Life Support Sys tem (ECLSS), which ens ures the survival of the as tronauts for s uch m is s ions . Thes e fram e conditions will im pos e a high degree of clos ure and a high reliability for the ECLSS. In this thes is , firs tly, the different ECLSS technology/com ponent options are pres ented, and its s uitability for a long duration hum an s paceflight is analyzed. From all technologies the m os t prom is ing, regenerative s ys tem s for atm os phere, water and was te m anagem ent are s elected in order to exam ine them as part of a com plete ECLSS. Different approaches to evaluate the reliability of com plex s ys tem s are analyzed. Since the failure of a com ponent within the s ys tem does not neces s arily lead a failure of the entire ECLSS, as the s ys tem is able to com pens ate for s om e failures , the Stochas tic Dynam ic Dis crete Sim ulation (SDDS) m ethod is s elected. To carry out an SDDS, a robus t and adaptable ECLSS m odel s im ulation is required. A new s oftware is developed, bas ed on the s im ulation tool Environm ent for Life-Support Sys tem s Sim ulation and Analys is (ELISSA) from the Ins titute of Space Sys tem s - Univers ity of Stuttgart. As a res ult of as tochas tic s im ulation a lis t of failure tim es is obtained, which can be treated us ing the Maxim um Likelihood Es tim ation (for param etric m odels ) or the Kaplan-Meier m ethod (for non-param etric m odels ), to define the reliability of the s ys tem . The input data required to apply the SDDS are the reliabilities of each pos s ible com ponent of the ECLSS. The reliability of each com ponent is defined by the failure rate or its parts . It can be s een, that the us e of redundancies (s pare parts ) is es s ential for long duration m is s ions , as the reliability of the s ys tem without them after 60 days is lower than 50%. The analys is of all com ponents , including their s pare parts , is carried out with the Multi-Opbjective Optim ization Problem to achieve a high reliability with the lowes t pos s ible mass. Both m ethodologies , SDDS and MOOP have been im plem ented creating the us er-friendly new s oftware RELISSA. Finally, as an exam ple, RELISSA is us ed to analyze a m anned Mars m is s ion. With this analys is , technologies currently in us e (on board ISS) are com pared with new technologies (currently under developm ent), with the potential to reduce the s ys tem m as s . The res ults clearly s how that the new technologies can s ignificantly reduce the m as s of the s ys tem , for res ults of s im ilar reliability. With thes e res ults , the need of developm ent efforts of ECLSS technologies for m anned m is s ions beyond Low Earth Orbit is corroborated.
