ESTCube-2 tähejälgija riistvaraarendus

In English: Star trackers are used on satellites for accurate attitude determination. This thesis focuses on developing and testing the hardware for the ESTCube-2 star tracker prototype. The workflow consisted of selecting suitable components, creating a schematic and a PCB layout, assembling and testing the hardware. The created hardware can take images with an image sensor and transmit the image data to a computer. Some software was written to ease the testing of the hardware. The software allows users to control power buses, update the FPGA configuration, configure the image sensor and view the captured images from a personal computer. The created hardware serves as a basis for future software development and the creation of the flight model of the ESTCube-2 star tracker. Eesti keeles: Tähejälgijaid kasutatakse satelliitide täpse asendi määramiseks. Käesolev bakalaureusetöö kirjeldab ESTCube-2 tähejälgija prototüübi riistvaraarendust ning selle testimist. Töö käigus valiti sobivad komponendid, koostati elektriskeem ja trükkplaadi disain, koostati ja testiti tähejälgija riistvara. Loodud seade on võimeline tegema pildianduriga pilte ja väljastama pildiinfot arvutisse. Riistvara testimiseks loodud tarkvara laseb arvutist lülitada tähejälgijal sisse/välja toitepingeid, uuendada FPGA konfiguratsiooni, konfigureerida pildiandurit ning laseb vaadata pildianduri tehtud pilte. Loodud riistvara on aluseks tulevasele tarkvaraarendusele ja tähejälgija lennumudeli valmistamisele

Coulomb drag propulsion experiments of ESTCube-2 and FORESAIL-1

This paper presents two technology experiments – the plasma brake for deorbiting and the electric solar wind sail for interplanetary propulsion – on board the ESTCube-2 and FORESAIL-1 satellites. Since both technologies employ the Coulomb interaction between a charged tether and a plasma flow, they are commonly referred to as Coulomb drag propulsion. The plasma brake operates in the ionosphere, where a negatively charged tether deorbits a satellite. The electric sail operates in the solar wind, where a positively charged tether propels a spacecraft, while an electron emitter removes trapped electrons. Both satellites will be launched in low Earth orbit carrying nearly identical Coulomb drag propulsion experiments, with the main difference being that ESTCube-2 has an electron emitter and it can operate in the positive mode. While solar-wind sailing is not possible in low Earth orbit, ESTCube-2 will space-qualify the components necessary for future electric sail experiments in its authentic environment. The plasma brake can be used on a range of satellite mass classes and orbits. On nanosatellites, the plasma brake is an enabler of deorbiting – a 300-m-long tether fits within half a cubesat unit, and, when charged with -1 kV, can deorbit a 4.5-kg satellite from between a 700- and 500-km altitude in approximately 9–13 months. This paper provides the design and detailed analysis of low-Earth-orbit experiments, as well as the overall mission design of ESTCube-2 and FORESAIL-1.Peer reviewe

Coulomb drag propulsion experiments of ESTCube-2 and FORESAIL-1

This paper presents two technology experiments – the plasma brake for deorbiting and the electric solar wind sail for interplanetary propulsion – on board the ESTCube-2 and FORESAIL-1 satellites. Since both technologies employ the Coulomb interaction between a charged tether and a plasma flow, they are commonly referred to as Coulomb drag propulsion. The plasma brake operates in the ionosphere, where a negatively charged tether deorbits a satellite. The electric sail operates in the solar wind, where a positively charged tether propels a spacecraft, while an electron emitter removes trapped electrons. Both satellites will be launched in low Earth orbit carrying nearly identical Coulomb drag propulsion experiments, with the main difference being that ESTCube-2 has an electron emitter and it can operate in the positive mode. While solar-wind sailing is not possible in low Earth orbit, ESTCube-2 will space-qualify the components necessary for future electric sail experiments in its authentic environment. The plasma brake can be used on a range of satellite mass classes and orbits. On nanosatellites, the plasma brake is an enabler of deorbiting – a 300-m-long tether fits within half a cubesat unit, and, when charged with - 1 kV, can deorbit a 4.5-kg satellite from between a 700- and 500-km altitude in approximately 9–13 months. This paper provides the design and detailed analysis of low-Earth-orbit experiments, as well as the overall mission design of ESTCube-2 and FORESAIL-1.</p