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Abstract: In considering the design activities of a stratospheric gondola for a multiuser experiment, the exchange of information between the structural designer and the various teams involved may be a critical issue. In fact, only part of the information is available at the beginning of the project, thus necessitating the use of a trial-and-error approach that leads to results which involve considerable expenditure. For small-and medium-size experiments, the problem of the exchange of information from the mechanical designer's point of view can easily be solved by using a pre-built gondola supplied by a hypothetical launch consortium. This is what we proposed as the "Strato-Bus" approach at the ESA Symposium 2009. Furthermore, in 2011 we also introduced a possible solution of a multi-user gondola design: a shared design for many combinations of experiments, the total weight of which is just below the maximum lift capacity of the balloon produced by several dedicated manufactories. But when the characteristics of the instrumentation make the use of a pre-built platform impossible, the problem of exchanging information arises once again, and this is what we have experienced in the case of the Large-Scale Polarization Explorer (LSPE) experiment. The design activities of the LSPE gondola are used here in order to introduce a "systematic approach" that is capable of saving both time and money for each team involved in the overall project.
Abstract: Thanks to the high latitude of the location the new scenario of the Svalbard Islands as well as that of the already operative Swedish launch base is very close to becoming a principal launching site for Long Duration Ballooning (LDB) arctic campaigns. LDB flights, rather than mid latitude flights that last several hours have become a suitable framework for all efforts to create low cost campaigns. The scientific world, which uses balloons to record measurements beyond the atmosphere, needs both frequently scheduled campaigns and an optimized organization capable of reducing flight costs. It is obvious that a reducing of general costs means keeping in mind, during all design phases, versatility and the standardization of common facilities such as gondola frame as well as the protection of the solar panels upon landing etc. The multi-user payload is certainly the first step for reducing launch costs. Each balloon is launched as much as possible when its payload hosts a number of experiments that weight just a little less than its maximum lifting capacity, apart from the necessary their mutual compatibility. A second step, concerns the optimization of the gondola frame design. It must manufacture gondolas easy to assemble, transport and as well as be easy to modify in shape in order to host a different combination of a given number of experiments, once these have been selected by a scientific authority for the same balloon. The new concept in designing platform which takes advantage of special mechanical elements that are capable both of jointing different beam lengths and of distributing tensile or compression stress only is proposed. The gondola can be assembled simply by only cutting structural aluminum beams into different lengths. Differences between traditional rigid structures and the new concept of construction are pointed out, as a reduction in the total weight and as an easy way to balance the gondola almost without adding extra weight. An example of how the new mechanical joint works and how its behavior closely approximates to the theoretical one is also demonstrated. The study is devoted to design the platform of one of the next balloon experiments (funded by ASI): The Large Scale Polarization Explorer (LSPE).
Abstract: Researchers in astrophysics and earth observation are still interested in balloon campaigns for making measurements outside the atmosphere. It is possible to trim a bit more from the ballooning costs by increasing the number of parts that can be reused, and by the careful design, the integration and the consolidation of a standard gondola apparatus (something like the mass production of cars). This paper will focus on one of the aspects capable of reducing costs, namely reusable power sources such as solar panels (SP) and fuel cells (FC) and how to protect them during the most difficult phases of the flight (take-off, landing). We will describe two possible ways of deploying and stowing a SP, and report the results of a thermal simulation aimed at ascertaining whether FC may be used in a stratospheric balloon environment.
Abstract: The interest in LDB flights has grown dramatically over the years. However, since the success of a mission is strongly dependent on the costs, one possible way to improve the overall efficiency of a campaign is to perform different experiments during the same flight, even though this requires more versatile platforms. The design of this kind of system is very difficult to accomplish. In this paper the authors discuss the main issues related to the design of multi-experiment platforms for LDB flights, and try to provide some guidelines for making the approach more systematic. An application to a twoexperiment platform design problem is also briefly described.
Abstract: In this paper the authors will describe the work which the University of Florence and IFAC-CNR (Florence) have performed in order to design an innovative platform for High-latitude LDB flights based on multi-experiments and versatility concepts. In order to satisfy the functional requirements and difficult structural constraints in terms of stiffness, strength and weight, the authors will describe an innovative approach to designing the gondola using problem-solving techniques, virtual prototyping and topology optimization in a systematic way. By means of these tools, a set of optimized geometries has been tested, starting from the first implementation of the BarSPOrt experiment's platform. Some of these solutions will be described.
Abstract: In addition to stepping through the typical hardware parts of an Attitude Control System borne for stratospheric platform, the paper describes some fast position sensors. The use of two axis magnetometers at high latitude, even though with a lower accuracy, is analyzed. A high-accuracy motorized sun tracker based on a Position Sensitive Detector photodiode capable of driving the gondola in pointing or scanning mode in any given arbitrary anti-sun direction is also presented. Lastly, as an important part of the entire sensor development project, the paper describes a simulation of the thermal behavior of a pressurized cylinder in which electronic photosensitive devices and a CPU system are housed. To employ electronic device built within a commercial temperature range and intended to stay on the ground, it is extremely important to have a pressurized and conditioned environment in order to avoid a reduction in the performances of some ACS components.
Abstract: In this paper we show the improvements of assimilating water vapour data into a LAM (Limited Area Model) for a case study of a meteorological event over Calabria, the southernmost tip of Italian peninsula, and we show how Lidar could contribute to give better results. The case study here presented is named "Soverato flood" and represents a prolonged and intense precipitation event. We will discuss this event using ECMWF analysis/forecast cycle as dynamical boundary conditions for RAMS (Regional Atmospheric Modeling System) integration. Two simulations are compared: first one is made using RAMS model without assimilation of water vapour data, the second starts from a RAMS pre-run that assimilates precipitable water data.
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