Abstract This master thesis is divided into two parts, one pedagogical and one engineering. The purpose of the pedagogical part of this master thesis was to investigate how students learn during projects. At the Royal Institute of Technology in Stockholm, three larger student projects occurred where the students themselves developed an probe that was launched into the atmosphere. The supervisors of the projects wanted to find out how the students learn during the project. The thesis includes in-depth interviews with current and former university students. In order to compare and gain new perspectives on learning, the study also included interviews with high school students to identify their corresponding experiences of learning in their final projects in Swedish upper secondary school. The result from this study shows that the students learn through participating in activities, collaboration and communication. Giving the students responsibility, a mutual goal and an important assignment makes them collaborate and learn from experience through reflection. The purpose of the engineering part of this master thesis was to investigate samples that were collected during the Arctic Summer Cloud Ocean Study in the summer of 2008. The samples were studied by using a scanning electron microscope. The results of the thesis are consistent with former studies on samples collected in Arctic. The images from the microscope showed microgels and how the gels assembled into larger particles, particles which can play a crucial role in the formation of clouds.

This bachelor's thesis aims to implement a wave propagation experiment on Field-Programmable Gate Array to detect the signal strength at pre-defined frequencies for use in sounding rocket experiments. This includes the choice of suitable components such as analog to digital converters, filters, voltage regulators, and amplifiers. The board prototype was designed by keeping in mind the need for a miniaturized solution that would still provide the wanted results, by following design guidelines. The second part of the project involves the design of the software in a hardware description language. An analysis in MATLAB® was done to determine the parameters needed to successfully reconstruct the transmitted signal on the receiver, while still being able to fit on the given FPGA. To make sure of that, a simulation was performed on ModelSim a tool for simulation and debugging for VHDL. From the simulations, it can be concluded that this design is feasible and that this project gives the basis for further development, to create a viable solution for a wave propagation experiment with a miniaturized payload. / Denna kandidatuppsats syftar till att implementera ett vågutbredningsexperiment på Field-Programmable Gate Array för att detektera signalstyrkan vid fördefinierade frekvenser för användning i sonderingsraketexperiment. Detta inkluderar val av lämpliga komponenter som analog till digital omvandlare, filter, spänningsregulatorer och förstärkare. Kortprototypen designades genom att ha i åtanke behovet av en miniatyriserad lösning som fortfarande skulle ge önskat resultat, genom att följa designriktlinjerna. Den andra delen av projektet involverar design av programvaran i ett hårdvarubeskrivningsspråk. En analys i MATLAB® gjordes för att bestämma parametrarna som behövs för att framgångsrikt rekonstruera den sända signalen på mottagaren, samtidigt som den fortfarande kan passa på den givna FPGA. För att säkerställa det gjordes en simulering på ModelSim ett verktyg för simulering och felsökning för VHDL. Från simuleringarna kan man dra slutsatsen att denna design är genomförbar och att detta projekt ger grunden för vidareutveckling, för att skapa en hållbar lösning för ett vågutbredningsexperiment med en miniatyriserad nyttolast. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

With the help of sounding rockets, the Earth’sionosphere can be studied by ejecting cylindrical units thatmeasure various electromagnetic properties while falling. Theseunits are also known as Free Falling Units (FFUs). The goal of thisproject is to turn the FFUs into autonomous gliders by designingdeployable wings. A spring-loaded Scissor Structural Mechanism(SSM) was chosen as the main deploying mechanism. Furthermore,the conceptual wing design was simulated in Siemens NXand a structural analysis was performed in NASTRAN. Finally, aprototype was manufactured to confirm if the SSM would workas intended. Initial simulation results showed great promise withthe proper choice of materials. Due to resource limitations, theprototype could not be compared to the simulation. Based onthe prototype results, the design must be reinforced or alteredto become stronger and more rigid. / Med hjälp av sondraketer kan jordensjonosfär studeras genom att skicka ut cylindriska enhetersom mäter diverse elektromagnetiska egenskaper medan defaller. Dessa enheter är också kända som FFUs (Free FallingUnits). Målet med detta projekt var att förvandla dessa enhetertill autonoma glidare genom att designa utfällbara vingar.En fjäderbelastad saxmekanism valdes som den huvudsakligautfällningsmekanismen. Vidare simulerades den konceptuellavingdesignen i Siemens NX och strukturen analyserades i NASTRAN.Slutligen tillverkades en prototyp för att bekräfta omsaxmekanismen skulle fungera som avsedd. De första simuleringsresultatenvisade sig vara lovande med rätt materialval.På grund av begränsningar i resurser, kunde inte prototypenjämföras med simuleringen. Baserat på prototypresultaten måstedesignen förstärkas eller ändras för att bli starkare och mer styv. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

The aim of this bachelor’s thesis is to design theelectronics for an autonomous glider to be used in a soundingrocket experiment with return to launch site functionality. Theelectronics includes a battery solution, servos and a hardwareplatform for communication and control software. All of theseparts need to be suited for a specified form factor and someextreme environments such as low temperature and vacuum. Theelectronics have been designed based on calculations for powerconsumption and temperature dependency. The system had to bepower efficient since the space for batteries is limited. Servos werecustom designed with motors and drivers to optimize both spaceand efficiency. Based on testing, simulations and calculations ofthe design the following can be concluded. The proposed systemhas the capability to meet the requirements to control and flythe glider all the way back to launch site even in a worstcasescenario. Thus an electronics system for the autonomousglider solution is feasible even with the strict requirements andconditions. / Syftet med detta kandidatexamensarbete äratt designa elektroniken till en autonom glidflygare vars uppgiftär att återföra experiment uppskjutna med en sondraket. Elektronikeninnefattar en batterilösning, servos för styrning samten hårdvaruplattform för kommunikation och kontrollsystemet.Alla dessa delar ska implementeras i ett begränsat utrymmeoch klara av låga temperaturer samt vakuum. Beräkningar avenergiförbrukning och temperaturberoende hos de olika komponenternahar gjorts för att designen ska klara förhållandena.Elsystemet måste vara effektivt nog för att kunna drivas medett batteri kompatibelt med det givna utrymmet. Egendesignadeservon är framtagna med motorer och drivare för optimeradeffektivitet och storlek. Tester, simulationer och beräkningarvisar att det föreslagna systemet är kapabelt att för de angivnakraven flyga glidflygaren tillbaka till basen. Elsystemet haräven marginaler nog att klara detta under de mest påfrestandeförutsättningarna. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

The B2D2 student experiment aims to study theEarth magnetic field by releasing a free falling unit (FFU) from asounding rocket. The power system of the FFU needs to supply allsubsystems with sufficient power and energy during the flight.This is achieved with two lithium cells and voltage regulatorsthat produce the required voltages and can deliver the necessarycurrent. The voltage regulators are tested on prototype PCBsand their performance evaluated. An attitude determination andcontrol system is needed to stabilise the FFU after release. Motordrive systems are custom designed for this purpose. The powerconsumption of the FFU is computer-simulated based on mea-surements on existing hardware. According to tests conducted,switching regulator designs with inductors are the best candidatesfor the power system. The chosen designs have sufficient marginsin current capacity to power the experiment during the durationof the mission with the chosen battery cells. / Målet med studentexperimentet B2D2 är att studera det jordmagnetiska fältet genom att släppa en experimentmodul från en sondraket. Strömförsörjningssystemet i experimentmodulen behöver kunna leverera tillräcklig strömstyrka och energi till alla delsystem under experimentets varaktighet. Detta åstadkoms med två litiumceller och spänningsomvandlare som producerar de spänningar som behövs vid den strömstyrka som krävs. Spänningsomvandlarna testas på prototypkort för att utvärdera deras prestanda. Ett attitydkontrollsystem behövs för att stabilisera experimentenheten efter dess att den släppts. Till detta attitydkontrollsystem utvecklas ett motordrivsystem. Strömförbrukningen av experimentenheten simulerades utifrån mätningar på existerande hårdvara. Utifrån utförda tester bedöms de induktorbaserade switchande spänningsomvandlarna vara de lämpligaste. De valda kretsdesignerna har tillräcklig strömkapacitetsmarginal för att kunna strömförsörja experimentenheten under experimentets varaktighet med de valda battericellerna. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

This master thesis is divided into two parts, one pedagogical and one engineering. The purpose of the pedagogical part of this master thesis was to investigate how students learn during projects. At the Royal Institute of Technology in Stockholm, three larger student projects occurred where the students themselves developed a probe that was launched into the atmosphere. The supervisors of the projects wanted to find out how the students learn during the project. The thesis includes in-depth interviews with current and former university students. In order to compare and gain new perspectives on learning,the study also included interviews with high school students to identify their corresponding experiences of learning in their final projects in Swedish upper secondary school. The result from this study shows that the students learn through participating inactivities, collaboration and communication. Giving the students responsibility, a mutual goal and an important assignment makes them collaborate and learn from experience through reflection. The purpose of the engineering part of this master thesis was to investigate samples that were collected during the Arctic Summer Cloud Ocean Study in the summer of 2008. The samples were studied by using a scanning electron microscope. The results of the thesis are consistent with former studies on samples collected in Arctic. The images from the microscope showed microgels and how the gels assembled into larger particles, particles which can play a crucial role in the formation of clouds.

Space exploration drives the human expansion inthe universe. Succeeding in this challenge demands familiarityof the near earth space environment, achieved through soundingrocket experiments that often are lost upon return from space. Afuture proof solution is needed and this study aims to investigatethe aerodynamics of a modular self returning glider attachment.To aid conceptual design, simulations were first performedusing potential theory in the software XFLR5. The resultingdesign was then analysed further using Computational FluidDynamics (CFD) in Simscale after which a glider prototype wasbuilt and tested.The study shows that while it is possible to fulfill the projectrequirements when only modelling the wing surfaces, the gliderfuselage contributes to a destructive drag and pitching moment.Consequently, future prototypes demand increasing the lift orreducing the drag, as well as ensuring longitudinal stability. Moreresources need to be invested into further CFD modelling andprototype testing. / Utforskning av rymden driver denmänskliga expansionen ut i universum. För att lyckas meddet krävs dock kunskap om rymden närmast oss, vilketuppnås genom experiment i sondraketer som ofta förlorasvid återkomst. En framtidssäker metod behövs och därförundersöks aerodynamiken av en modulär och självåtervändande glidarlösning.För att underlätta genomförandet av den konceptuella designen så gjordes först simuleringar i XFLR5 med potentialteori.Den resulterande glidaren analyserades sedan vidare iflödesmekaniska beräkningsprogram (CFD), vartefter en prototypbyggdes och testades i verkligheten.Studien visar att det är möjligt att uppfylla projektkravengenom att modellera vingarna, men glidarens flygkropp bidraremellertid till ett destruktivt luftmotstånd och longitudinelltvridmoment. Därför måste framtida prototyper designas föratt uppnå större lyftkraft, minska flygkroppens dragkraft ochsamtidigt uppnå longitudinell stabilitet. Mer resurser måsteläggas på djupare CFD-modellering och prototyptestning. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm