Browsing by Author "Niemelä, Petri"
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Item Aurinkopaneelien toiminnallisuuden verifiointi nanosatelliitteihin(2019-05-22) Kettunen, Ville-Valtteri; Niemelä, Petri; Sähkötekniikan korkeakoulu; Turunen, MarkusItem Calibration of RADMON radiation monitor onboard Aalto-1 CubeSat(ELSEVIER SCI LTD, 2020-07-01) Oleynik, Philipp; Vainio, Rami; Punkkinen, Arttu; Dudnik, Oleksiy; Gieseler, Jan; Hedman, Hannu Pekka; Hietala, Heli; Hæggström, Edward; Niemelä, Petri; Peltonen, Juhani; Praks, Jaan; Punkkinen, Risto; Säntti, Tero; Valtonen, Eino; University of Turku; NASU - Institute of Radio Astronomy; University of Helsinki; Department of Electronics and NanoengineeringRADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the ΔE-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed.Item Communications Subsystem Test Bench and Design Verification for Foresail-1 CubeSat(2021-12-13) Kettunen, Ville; Niemelä, Petri; Sähkötekniikan korkeakoulu; Praks, JaanNanosatellites, with weight less than 10 kg have become very popular with the help of the CubeSat standard, low launch prices and usage of cheaper electronic components. Many new countries have launched their first satellite in this category. Educational institutions and amateurs have been able to build and launch satellites with limited resources, and many new companies use nanosatellites to provide new services. Unfortunately, the rapid development times and inexperienced teams brings up a problem with reliability. Many satellites in this category never make contact to a ground station and are congesting the low Earth orbits as space junk. The aim of this thesis is to create a framework for CubeSat communications subsystem testing. In this work, a test bench is created from current methods in the CubeSat testing practices, as well as industry level standardized tests. The tests are applied to theForesail-1 satellite communications subsystem development. A part of successful testing is a good design and therefore, a part of the thesis is dedicated to simulating and implementing matching circuits and filters to radio frequency signal paths of the mentioned satellite. Proper filter design and impedance matching ensures high efficiency for the transmit side and a high sensitivity for the receive side. The test benches are used to confirm that the Foresail-1 communications subsystem not only meets the requirements set to the system by the mission, but the requirements set by the regulation from the International Telecommunications Union. Additionally important aspects such as the Doppler shift is considered. The developed approach is documented, and it can be adapted to future CubeSat projects.Item Coulomb drag propulsion experiments of ESTCube-2 and FORESAIL-1(Elsevier Limited, 2020-12) Iakubivskyi, Iaroslav; Janhunen, Pekka; Praks, Jaan; Allik, Viljo; Bussov, Kadri; Clayhills, Bruce; Dalbins, Janis; Eenmäe, Tõnis; Ehrpais, Hendrik; Envall, Jouni; Haslam, Sean; Ilbis, Erik; Jovanovic, Nemanja; Kilpua, Emilia; Kivastik, Joosep; Laks, Jürgen; Laufer, Philipp; Merisalu, Maido; Meskanen, Matias; Märk, Robert; Nath, Ankit; Niemelä, Petri; Noorma, Mart; Mughal, Muhammad Rizwan; Nyman, Samuli; Pajusalu, Mihkel; Palmroth, Minna; Paul, Aditya Savio; Peltola, Tatu; Plans, Mathias; Polkko, Jouni; Islam, Quazi Saimoon; Reinart, Anu; Riwanto, Bagus; Sammelselg, Väino; Sate, Janis; Sünter, Indrek; Tajmar, Martin; Tanskanen, Eija; Teras, Hans; Toivanen, Petri; Vainio, Rami; Väänänen, Mika; Slavinskis, Andris; Department of Electronics and Nanoengineering; Jaan Praks Group; Eija Tanskanen Group; Esa Kallio Group; University of Tartu; Finnish Meteorological Institute; Estonian Student Satellite Foundation - ESTCube; Department of Electronics and Nanoengineering; University of Helsinki; Technical University of Dresden; Jaan Praks Group; Ventspils University College; University of TurkuThis 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.Item Design of reliable Electrical Power System for Foresail-1 Small Satellite(2020-05-18) Cheremetiev, Kiril; Niemelä, Petri; Sähkötekniikan korkeakoulu; Praks, JaanThis thesis covers design and testing of electrical power system (EPS) for Foresail-1 3U CubeSat, which is will be launched to low-earth orbit for 5 years. EPS is a mission critical subsystem that provides electrical power to avionics subsystems for the lifetime of the mission. With extensive use of commercial-of-the-shelf components and heightened mission demands, ensuring reliability of the EPS through-out the mission will require sound engineering design choices and extensive testing. In the first part of the thesis, hardware design of the Foresail-1 EPS will be reviewed, covering circuit design for space environment and component selection. In the latter part of the thesis, Foresail-1 development and testing philosophy will be explained with test results. Test results will cover maximum power point tracking battery charging and total dose test campaign held in December 2019.Item Foresail-2: Space Physics Mission in a Challenging Environment(Springer, 2023-12) Anger, Marius; Niemelä, Petri; Cheremetiev, Kiril; Clayhills, Bruce; Fetzer, Anton; Lundén, Ville; Hiltunen, Markus; Kärkkäinen, Tomi; Mayank, Mayank; Turc, Lucile; Osmane, Adnane; Palmroth, Minna; Kilpua, Emilia; Oleynik, Philipp; Vainio, Rami; Virtanen, Pasi; Toivanen, Petri; Janhunen, Pekka; Fischer, David; Le Bonhomme, Guillaume; Slavinskis, Andris; Praks, Jaan; Department of Electronics and Nanoengineering; Jaan Praks Group; Department of Electronics and Nanoengineering; Jaan Praks Group; University of Helsinki; University of Turku; Finnish Meteorological Institute; Austrian Academy of Sciences; University of TartuEarth’s radiation belts are extremely important for space weather because they can store and accelerate particles to relativistic energies, which can have a potential impact on satellite functionality, communications, and navigation systems. The FORESAIL consortium wants to measure these high-energy particle fluxes to understand the dynamics of the radiation belts with its satellite mission Foresail-2. The mission aims to measure magnetic ultra low frequency waves and the plasma environment in the magnetosphere around Earth. The captured data will help to improve our understanding of space weather, and in particular the dynamics of Earth’s radiation belts during periods of large disturbances inside the magnetosphere. A mission design analysis and several trade-off studies are conducted to find the requirements for the science payloads and spacecraft avionics design. Deducted from these requirements, four different payloads are proposed to gather science data in a highly elliptical orbit such as a geostationary transfer orbit. The precision magnetometer uses flux-gate technology to measure magnetic waves from 1 mHz to 10 Hz. The spin scanning particle telescope is built around a detector stack to measure electron spectra in the range of 30 keV to 10 MeV. Additionally, this mission serves as a technology demonstrator for the Coulomb drag experiment which proposes a new kind of electric solar wind sail utilising the Coulomb drag force imposed onto a 300 m long tether. The fourth payload investigates multilayer radiation shielding and single event effects. All payloads will be supported by a newly developed 6U platform using mostly commercial off-the-shelf components. Its proposed avionics face several unique design requirements rising from the payloads and the preferred highly elliptical orbit for this mission.Item Nanosatelliittien lento-ohjelmistojen laadunvarmistus(2014-05-06) Niemelä, Petri; Leppinen, Hannu; Sähkötekniikan korkeakoulu; Forsman, PekkaItem Narrowband LTE in Machine to Machine Satellite Communication(2018-06-18) Niemelä, Petri; Praks, Jaan; Sähkötekniikan korkeakoulu; Praks, JaanRecent trends to wireless Machine-to-Machine (M2M) communication and Internet of Things (IoT) has created a new demand for more efficient low-throughput wireless data connections. Beside the traditional wireless standards, focused on high bandwidth data transfer, has emerged a new generation of Low Power Wide Area Networks (LPWAN) which targets for less power demanding low-throughput devices requiring inexpensive data connections. Recently released NB-IoT (Narrowband IoT) specification extends the existing 4G/LTE standard allowing more easily accessible LPWAN cellular connectivity for IoT devices. Narrower bandwidth and lower data rates combined to a simplified air interface make it less resource demanding still benefiting from the widely spread LTE technologies and infrastructure. %% Applications & Why space Applications, such as wide scale sensor or asset tracking networks, can benefit from a global scale network coverage and easily available low-cost user equipment which could be made possible by new narrowband IoT satellite networks. In this thesis, the NB-IoT specification and its applicability for satellite communication is discussed. Primarily, LTE and NB-IoT standards are designed only for terrestrial and their utilization in Earth-to-space communication raises new challenges, such as timing and frequency synchronization requirements when utilizing Orthogonal Frequency Signal Multiplexing (OFDM) techniques. Many of these challenges can be overcome by specification adaptations and other existing techniques making minimal changes to the standard and allowing extension of the terrestrial cellular networks to global satellite access.Item Vibration Testing for Small Satellites(2024-04-22) Haakana, Tatu; Niemelä, Petri; Insinööritieteiden korkeakoulu; Viitala, RaineVibration testing is a crucial aspect of environmental testing for satellites. Ensuring the structural integrity and functionality in the rocket launch environment is a requirement for accepting the spacecraft for launch. This thesis explores vibration testing methods used in the aerospace industry for small satellites, with a focus on CubeSats. A vibration test campaign of the Aalto-3 student satellite is presented as an example to demonstrate these methods in practice. The Aalto-3 team participated in a test campaign program organized by the European Space Agency (ESA) in the summer of 2023. The goal of the test campaign was to verify the structural integrity of the satellite structure model. The test campaign included Quasi-Static and random vibration tests for each axis. This thesis advances the execution and results of the Aalto-3 vibration test campaign, providing practical insights for future satellite missions.
