Design and characterisation of subsystems and software for ESTCube-1 nanosatellite
Date
2019-07-04
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Abstract
Elektrilise päikesepurje tehnoloogia võimaldaks kosmosesondidel navigeerida planeetidevahelises ruumis ilma kütuseta, kasutades vaid päikesetuult ja elektrienergiat. Küll aga on tehnoloogiliselt keerukas päikesepurje purjetraadi väljakerimine, mis eeldab kosmosesondi pöörlemapanekut.
2013. aasta 7. mail maalähedasele orbiidile läkitatud tudengisatelliit ESTCube-1 oli esimene satelliit elektrilise päikesepurje katsetusmooduliga. Satelliit seati edukalt vajaliku pöörlemiskiirusega pöörlema, kuid purje väljakerimine ebaõnnestus mehaanilise tõrke tõttu katsetusmooduli motoriseeritud purjepoolis.
ESTCube-1 pöörlemapanekut ja päikesepurje katsetusmooduli juhtimist võimaldasid satelliidi pardaarvuti ja seda ümbritsevad liidesed, mille arendamise ja valideerimise tulemustele keskendub antud väitekiri. Pardaarvuti kogus mõõdiseid satelliidi asendi anduritelt, juhtis magnetmähiseid ning lülitas missioonilasti purjepooli mootorit, purjepooli kõrgepinge toiteplokki ja elektronkiirgureid. Lisaks vahendas pardaarvuti pilte pardakaamerast ning salvestas mõõtmistulemusi satelliidi alamsüsteemidelt et need hiljem maajaamale edastada. Satelliidi kaheaastase eluea jooksul ei täheldatud missioonikriitilisi tõrkeid pardaarvuti ega selle liideste töös. ESTCube-1 missioon aitas edukalt tõsta elektrilise päikesepurje tehnoloogia komponentide valmidusastet tulevasteks missioonideks.
Electrical solar wind sail (E-sail) technology would enable propellantless interplanetary navigation of space probes, using just solar wind and electricity. One of the main challenges of the technology is E-sail tether deployment, for which the space probe would be spun to a high angular rate. Launched on May 7th, 2013, the Estonian student satellite ESTCube-1 was the first spacecraft with an E-sail experiment payload. While the satellite was successfully spun to the spin rate necessary for the experiment, the motorised reel technology used on the payload proved immature for tether deployment. ESTCube-1 spin-up and payload control were enabled by the spacecraft on-board computer. This thesis is focused on the results of the development and in-orbit validation of the on-board computer and its interfaces to other related systems on the satellite. The on-board computer collected measurements from spacecraft attitude sensors, controlled its magnetic torquers, mediated camera images and stored telemetry from various subsystems for later transmission. The on-board computer also toggled the tether reel motor, electron emitters and controlled the high voltage supply for the E-sail tether. Throughout the two-year lifetime of the spacecraft, no mission-critical issues were encountered in the operation of the on-board computer or its interfaces. The ESTCube-1 mission successfully improved the technological readiness of E-sail components for future missions.
Electrical solar wind sail (E-sail) technology would enable propellantless interplanetary navigation of space probes, using just solar wind and electricity. One of the main challenges of the technology is E-sail tether deployment, for which the space probe would be spun to a high angular rate. Launched on May 7th, 2013, the Estonian student satellite ESTCube-1 was the first spacecraft with an E-sail experiment payload. While the satellite was successfully spun to the spin rate necessary for the experiment, the motorised reel technology used on the payload proved immature for tether deployment. ESTCube-1 spin-up and payload control were enabled by the spacecraft on-board computer. This thesis is focused on the results of the development and in-orbit validation of the on-board computer and its interfaces to other related systems on the satellite. The on-board computer collected measurements from spacecraft attitude sensors, controlled its magnetic torquers, mediated camera images and stored telemetry from various subsystems for later transmission. The on-board computer also toggled the tether reel motor, electron emitters and controlled the high voltage supply for the E-sail tether. Throughout the two-year lifetime of the spacecraft, no mission-critical issues were encountered in the operation of the on-board computer or its interfaces. The ESTCube-1 mission successfully improved the technological readiness of E-sail components for future missions.
Description
Väitekirja elektrooniline versioon ei sisalda publikatsioone
Keywords
ESTCube-1, satelliidid (tehn.), kosmosetehnoloogia, tarkvara, süsteemitarkvara