CharPa As early as 1961 Rosinski and Snow (1961) suggested that meteoroid ablation products could recondense and form solid nanometer-scale smoke particles in the altitude range of the upper mesosphere ( z= 60 - 110 km). Almost 20 years later, this idea was then substantially quantified in the work of Hunten et al. (1980) who presented the first detailed microphysical model of these particles by explicitly considering effects like meteoroid ablation, recondensation of new particle-embryos, particle growth by coagulation, and transport by eddy diffusion.   These calculations predicted typical concentrations of up to several thousand particles per cubic centimeter with radii in the 1-5 nm range in the upper mesosphere. Despite these tiny dimensions, it has been suggested that meteoric smoke particles (MSPs) are involved in a variety of atmospheric processes such as the nucleation of mesospheric ice clouds, heterogeneous chemistry, and the formation of nitric acid trihydrate (NAT)-particles in polar stratospheric clouds which are involved in ozone destruction in the polar spring (Rapp et al. 2006, Summers et al. 1999, Voigt et al., 2005).   Given all these points, it is obvious that there is a large scientific interest in the properties and global distribution of MSPs. However, despite this interest, the observational data base concerning MSPs is surprisingly scarce. The main reason for our ignorance in this respect is the extremely small dimensions of MSPs (typical radii are just a few nanometers) rendering their optical detection hardly feasible (e.g. Rapp and Lübken, 2001, 1999).   There is one possibility to measure such dust particles In-situ. The common instrument, used for this purposes is a Faraday cup. Such instruments were successfully flown and shown the presence of the dust in the mesosphere (e.g. Rapp et al. 2005, Lynch et al., 2005). The measured sign of dust is different from another measurements. Amyx et al. (2007) proposed that current was produced by triboelectric charging of dust grain on the electrode surface (creating electrostatic charge by contact and separation of materials). It involves the transfer of electrons between materials. The electrons from the material with a lower work function are transferred to the one with larger work function.The knowledge whether the current was produced by charged dust or not, will give better understanding of charging balance in the mesosphere. Also this will yield information about the composition of this dust, what is very important for all processes, described above.   Until now there were no experiments that addressed this issue. The aim of our project is to fill this gap.   Team: Irina Strelnikova (Leibniz-Institute of Atmospheric Physics IAP, Kühlungsborn, Germany) Li Quang (Leibniz-Institute of Atmosheric Physics IAP, Kühlungsborn, Germany) Jonas Hedin (Stockholm University, Sweden) Hannes Schmeiduch (Technische Universität München, Germany) Itikka The team has an ongoing rocket project - Supikoira - where they are building a hybrid rocket with electronics payload. One of the payload components is an inertial measurement unit (IMU1). Now they have a plan of a sounding rocket - Supikoira 2 – which will have an active stabilization and guidance system that requires an improved inertial measurement unit (IMU2).   Their scientific goal or more likely a technical goal is to build and then evaluate this improved inertial measurement unit. The goal will be fulfilled by testing the IMU2 in a real environment (REXUS rocket) and by analysing the data afterwards against the corresponding data of the REXUS rocket.   Team: Petri Rokka (Tampere University Of Technology, Finland) Eero Alkkiomäki (Tampere University Of Technology, Finland) Matti Hautala (Tampere University Of Technology, Finland) Mikko Hirvonen (Tampere University Of Technology, Finland) Tero Huttunen (Tampere University Of Technology, Finland) Ossi Mäkinen (Tampere University Of Technology, Finland) Ilpo Suominen (Tampere University Of Technology, Finland) Anssi Toivonen (Tampere University Of Technology, Finland) Vib-Bip - Vibration Effects on Biphasic Fluids. Their project is focused on the study of the behaviour of two-phase fluids (liquid and gas) under controlled harmonic vibrations in low-gravity conditions. The experiment consists in a test cell with form cylindrical cavities containing liquid (water or silicon oil) and air in different proportions. Vibrations of different frequencies and amplitudes will be applied to the whole system during the low gravity time of REXUS and it will be recorded with a camera in order to study the system behaviour with the videos obtained.   This experiment will allow getting insight into the influence that frequency and amplitude of vibrations have in the distribution of bubbles in the cavity. The experimental set-up surrounding the test cell consists on vibration generation and data acquisition systems. The test cell will be located on a commercial shaker which will generate vibrations with the required amplitudes and frequencies. Data acquisition subsystem consists on a high-speed camera and an illumination system based on an array of leds. The camera will be recording the behaviour of bubbles inside the cavity during all the flight time.   After the REXUS campaign the recorded videos will be analysed in order to obtain information on the behaviour of the system in microgravity. Results obtained will be compared with studies on the same system on ground. We expect to obtain valuable scientific results which could allow the development of new technologies based on two-phase fluids for applications in space and on Earth.   Team: Laura Duarte (Universitat Politecnica de Catalunya, Spain) Oscar Maldonado (Universitat Politecnica de Catalunya, Spain) Beatriz Gallardo