MEFISTO is a scientic instrument for the measurement of the low frequency electric eld in Mercury'smagnetosphere. It is a double probe electric eld instrument which will y onboard the MMO module of the BepiColombo mission, deploying a 15 m long wire boom in order to place the two probes for themeasurement of the electric eld far enough from the region electrostatically perturbed by the spacecraft.In the same way as any other mechanical system to be sent to space, MEFISTO needs to be deeplyinvestigated and tested in order to maximize the chances of a successful operation, but also to provethat the design requirements are satised. This Master Thesis describes the work carried out for theunderstanding and analysis of the torque dissipation on the mechanism, analyzing dierent features ofMEFISTO aecting its eciency, such as the geometrical accuracy of the dierent components or its tribological characteristics, providing results that have allowed to identify and evaluate the torque sinksof the wire boom system and a more detailed understanding of the behavior of the mechanism.

A novel Inatable Aerodynamic Decelerator (IAD) and platform for multi-pointmeasurements in the ionosphere, has been evaluated in the REXUS (Rocket-bourneEXperiments for University Students) program. The experiment, named LAPLander(Light Airbag-Protected Lander), was launched from Esrange 4th of March 2010 to analtitude of 88 km. LAPLander is a 3.043 kg right-circular cylinder with a diameter of24 cm and a length of 8.4 cm when the IAD is folded inside. At ejection LAPLanderis spin stabilized around its polar axis with 3.5-4 Hz. Contact was lost after ejectionwhich points to an electrical failure.This thesis presents an evaluation of the LAPLander IAD and a 6 Degrees-Of-Freedom (6-DOF) ight analysis. The 6-DOF simulation indicates that LAPLanderwould start to wobble, but if the rotation around its polar axis is decreased morethan estimated, it will start to autorotate. Perhaps with high enough angular rate todemand special precautions if a parachute is to be used as a mean of recovery. TheLAPLander IAD is designed to deploy at 6 km altitude. If the IAD was inated inspace instead, the resulting reduction in the ballistic factor at reentry would save masson the heat protection system, and thus save mass on the overall recovery system. AnIAD derived from the LAPLander IAD capable of a 250 km apogee reentry will beprovided.The IAD incorporate CO2 cartridges to inate the system, these do each containa CO2 valve. A pre-launch valve failure resulted in that LAPLander ew without aworking IAD. The valves are based on the principle that resistors heat Field's metalabove 62C (the melting temperature). The main mechanism of the valve failure seemsto be brittle creep in the Field's metal at this point. Some IAD ination-problematicshave been detected and this report provides a few recommendations.

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This thesis report describes the development of the optical system ALBERT (Alfvén Laboratory Baloon ExpeRimenT) that will fly from ESRange in 2011 as an auroral diagnostic unit for the PoGO-Lite mission. ALBERT has been developed at KTH in collaboration with the University of Southampton. ALBERT consists of two main systems. A support structure (mechanical system) and two spectrometers (optical system). The development started with a conceptual CAD assembly and the end objective was to have ALBERT manufactured. The mechanical system has been developed and manufactured in house and the parts are mainly manufactured from aluminum. The mechanical system was codeveloped with the thermal engineer to make sure the etalon temperature would be kept at a stable 20°C to ensure the performance of the spectrometers. The thesis also aimed to optimize the photometers for the use in the PoGO-Lite mission. The photometers have been designed to detect auroral oxygen emissions at´777.4nm and 844.6nm. The photometers consist of one interference filter, one Fabry-Pérot Etalon filter, two lenses, an aperture and one photomultiplier tube. The Fabry-Pérot Etalon filter is mounted on a tilting mechanism which enables the photometer to become a spectrometer. Extensive testing has been performed throughout this project with the objective to optimize the spectrometers. Knowhow about the system and its components enables the design of the aperture, a critical component that determines the performance of the´spectrometer. After extensive testing of the Fabry-Pérot Etalon filters and the interference filters with an Michelson interferometry spectrometer a final characterization of the Fabry-Pérot Etalon could be done using an Argon lamp and a high-end EMCCD camera. It could then be concluded that one of the etalons was not to specification and was rendered useless for ALBERT. The other etalon could be used and the optimization of the aperture for that spectrometer concluded in that a banana shaped aperture was the optimal. The inner and outer radii of the aperture corresponded to the radii of the rings from the interesting spectrum in the characteristic ring pattern produced by an etalon.

“Rocket deployed Atmospheric probes conducting Independent measurements in NorthernSweden” (RAIN) is a project where the team developed and constructed an experiment formultipoint sampling of aerosol particles in the middle atmosphere. The experiment is launchedwith a sounding rocket from Esrange in Kiruna March 2012. It consists of two probes which aremounted in the rocket cylinder. They will be ejected from this and fall from about 80 km height.During the fall through the atmosphere the probes collect samples on different heights. The postexperiment analysis is done with a scanning electron microscope (SEM). Atmospheric aerosolparticles play an important part in cloud formation and have impact on both climate andenvironment on earth. Sample-taking of them in high altitudes is a problem though and thereexists no good technique for this today.This Master thesis has two parts, one technical and one pedagogical, since it is written within theframes of the program Master of Science in Engineering and of Education. The technical partcovers the test of aerosol particle collection at ground level and the post-test SEM analysis ofthis. The pedagogical part describes the work with spreading interest for science and technologyby school visits presenting project RAIN.

Solid Rocket Motors (SRMs) are employed in many space launch applications from the booster rockets onthe now retired Space Shuttle to the new European launch vehicle Vega. Preliminary design of thesecomplex three dimensional SRMs, given certain requirements and limitations can be considered as anoptimization process where a best geometrical solution is sought resulting in a desirable thrust profile. Inthis project, a derivate free direct search package titled NOMAD is employed together with the internallydeveloped numerical burnback analysis tool SRP-GEO and ballistic solver SRP. An analytical model for theburnback analysis tool is also developed to take advantage of the support for surrogate functions withinNOMAD. Due to the local nature of the optimizer, the results for complex geometries are shown toconverge toward configurations different from the globally optimal geometries. Yet in most instances, theresulting calculated thrust profiles are shown to correlate well with the desired counterpart. This highlightsthe importance of carefully chosen initial values and boundaries while also emphasize the many possiblesolutions to a single problem.

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The HPEP (High Performance Electric Propulsion) thruster is expected to be the outcomecof an innovative project initiated by the Swedish Space Corporation. It combines the concept of a 10 kW electrodeless plasma thruster designed by the Elwing Company and the ADN based monopropellant LMP-103S developed by ECAPS and used in the HPGP thrusters of the Prisma Satellites. Using a chemically energetic propellant in an EP thruster will allow mass and cost reduction by providing two propulsion systems sharing the same tank. This thruster will be suitable for the apogee raising manoeuvre of geostationary satellites; it will allow to carry more transponders and to obtain a better return on investment than with a classical apogee kick motor. This Master Thesis focuses on the design and test of the injector that will thermally decompose the liquid LMP-103S so it can enter in the plasma chamber in a gaseous state. The heating power required by the injector is calculated, which leads to a final design composed by a cartridge heater of 400 W inserted in a stainless steel cylinder. The liquid flows through seven other holes drilled around the heater. This injector is tested at both atmospheric and low pressure with deionized water. Results regarding the power required to vaporize water confirm the theoretical estimation. Steam flow without any liquid droplets is achieved in steady state at low pressure with a maximum temperature on the surface of the injector between 230°C and260°C.

The Polarized Gamma-ray Observer Lite (PoGOLite)  is a balloon experiment which will  measure polarization of soft gamma rays in the energy range of 25 - 80 keV. Together with PoGOLite will also an auroral diagnostics package called Alfvén Labo- ratory Balloon ExpeRimenT (ALBERT) fly to measure auroral emissions as well as the surrounding background. The main part of ALBERT is two spectrophotometers that consist of a photo multiplying tube, lenses and a Fabry-Perot etalon. The Fabry-Perot etalons are mounted in a lens mount  that  is angle adjustable with  a stepper motor based linear actuator.  To support the instruments and to keep the etalons at a stable temperature  there are an multitude  of sensors and controllers at work.  The sensor data is collected organized and stored in a onboard memory as well as sent down to ground for real time analysis. This thesis covers the design and construction of the electronics as well as the VHDL  code for the main controller.  It is also supposed to work as a manual over how to run the experiment.