The development of a test facility for satellite experiments

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: This thesis addresses the problem of designing and implementing a planar air bearing test facility for satellite experiments. The test facility’s purpose is to provide a testbed for researchers to validate their projects and to perform experiments related to the fieldof spacecraft and space systems.The scope of the project includes the design and implementation of an air bearing vehicle, a pose estimator which measures the states of the vehicles being operated on the test facility, and a demonstration payload which can perform a control manoeuvre with the vehicle to showcase the test facility’s capabilities. An air bearing vehicle was designed and constructed, which successfully facilitated low friction movement on a glass platform. This low friction movement emulates the orbital dynamics of satellites withthree degrees of freedom.A supporting propellant refill station was also designed and constructed to enable the refilling of the vehicle’s gas supply between experiments.The air bearing vehicle carries a payload which typically consists of an on-board computer (which can control the vehicle), along with any other hardware which is specific to the experiment being conducted on the test facility. A custom cold gas thruster nozzle was designed for use on the air bearing vehicle. This nozzle was manufactured usinga fused deposition modelling 3D printer. The nozzles used on the vehicle were characterised using a custom-built test rig andwere found to meet all specifications required for the vehicle. A feedback and communication system (FCS) was designed and implemented, which is responsible for measuring the positions and velocities of the vehicles on the table. This data is logged and displayed to the user in near-real time. The FCS can also wirelessly communicate pose information to the payloads carried by the vehicles and can receive relevant info from the payloads to display and log. A demonstration payload was designed to showcase the capabilities and functioning of the test facility. This payload includes a control system that controls the vehicle to perform a manoeuvre to move from an initial coordinate to a target coordinate.The demonstration payload successfully showcased the test facility.Aside from some minor issues, the practical implementation of the test facility performedwell and successfully met all requirements. The test facility will provide many advantages for future researchers, allowing them to validate and demonstrate their projects, as well as give them valuable practical experience.
AFRIKAANSE OPSOMMING: Hierdie proefskrif behandel die probleem van die ontwerp en implementering van 'n lugdraende toetsfasiliteit vir satellieteksperimente. Die doel van die toetsfasiliteit is om 'n toetsbed aan navorsers te bied om hul projekte te bekragtig en om eksperimenteuit te voer wat verband hou met die veld van ruimtetuie en ruimtestelsels. Die omvang van die projek sluit in die ontwerp en implementering van 'n lugdraende voertuig, 'n orientasie-afskatterwat die toestande van die voertuie wat op die toetsfasiliteit gebruik word, meet, en 'n demonstrasie-loonvrag wat 'n beheervan die voertuig kan uitvoer om die funksies van die fasiliteitte vertoon.'nLugdraende voertuig is ontwerp en gebou, wat lae wrywing op 'n glasplatform suksesvol moontlik gemaak het. Hierdie beweging met lae wrywing boots die wenteldinamika van satelliete met drie vryheidsgrade na. 'nOndersteunende dryfstofvulstasie is ook ontwerp en gebou om die hervul van die gastoevoer tussen eksperimente moontlik te maak. Die lugdraende voertuig dra 'n loonvragwat gewoonlik bestaan uit 'n aanboordrekenaar (wat die voertuig kan beheer), saam met enige ander hardeware wat spesifiek is vir die eksperiment wat op die toetsfasiliteit gedoen word. nSpesiale spuitkop vir 'n stuweris ontwerp vir gebruik op die lugdraende voertuig. Hierdie spuitkop is vervaardig met behulp van 'n versmelte neerslagmodelle 3D-drukker. Die spuitpunte wat op die voertuig gebruik word, is gekenmerk deur 'n pasgemaakte toetsbuis en daar wasgevind dat dit aan alle spesifikasies voldoen.'nTerugvoer-en kommunikasiestelsel is ontwerp en geïmplementeer wat verantwoordelik is vir die meting van die posisies en snelhede van die voertuie op die tafel. Hierdie data word aangeteken en in die regte tyd aan die gebruiker vertoon. Die Terugvoer-en kommunikasiestelsel kan ook draadlose posisie-inligting kommunikeer aan die loonvragte wat deur die voertuie vervoer word en kan relevante inligting van die loonvragte ontvang om te vertoon en aan te meld.'nDemonstrasie-loonvrag is ontwerp om die funksies en funksionering van die toetsfasiliteit ten toon te stel. Hierdie loonvrag bevat 'n beheerstelsel wat die voertuig beheer om van 'n aanvanklike koördinaat na 'n teikenkoördinaat te beweeg. Die demonstrasie-loonvraghet die toetsfasiliteit suksesvol ten toon gestel.Afgesien van 'n paar klein probleme, werk die praktiese implementering van die toetsfasiliteit goed en voldoen dit aan alle vereistes. Die toetsfasiliteit bied baie voordele vir toekomstige navorsers, wat hulle in staat stel om hul projekte te bekragtig en te demonstreer, sowel as waardevolle praktiese ervaringte verkry.
Description
Thesis (MEng)--Stellenbosch University, 2021.
Keywords
Satellites -- Experiments, UCTD, Astronautics -- Communication systems, Air-bearing vehicles, Space shuttles -- Payloads
Citation