Current barriers and factors of success in the diffusion of satellite services in Europe

Satellite services benefit civil society by helping tackle challenges such as climate change, the digital divide, etc. They have the potential to deliver concrete benefits to European society through innovative services supporting economic, societal and environmental policies. Such benefits can trigger increased public support for space in Europe. However, this potential has yet to be achieved. This paper argues that technological bias, the diversity of interests and initiatives among stakeholders and their individual actions do not always serve their collective objective to ensure wide diffusion of satellite services. It draws on theories of diffusion of innovation and on its authors' participatory work with the space and the user communities and at their interface in an effort to help diffuse satellite services within civil society. One of the major causes of insufficient service diffusion is the weakness of the interface between the space and user communities; some of factors that currently contribute to this state of affairs are the space community's over-reliance on publicly financed, technical demonstration projects as solutions to service diffusion; insufficient coordination by public authorities of innovation policies and programmes with other public policies and objectives; and an insufficient integration of satellite services within users' culture, traditional tools and services. The discussion allows for conclusions to be drawn on how the system of stakeholders could function better in order for satellite services to be successfully diffused in Europe.     

Resistance of bacterial endospores to outer space for planetary protection purposes--experiment PROTECT of the EXPOSE-E mission

Spore-forming bacteria are of particular concern in the context of planetary protection because their tough endospores may withstand certain sterilization procedures as well as the harsh environments of outer space or planetary surfaces. To test their hardiness on a hypothetical mission to Mars, spores of Bacillus subtilis 168 and Bacillus pumilus SAFR-032 were exposed for 1.5 years to selected parameters of space in the experiment PROTECT during the EXPOSE-E mission on board the International Space Station. Mounted as dry layers on spacecraft-qualified aluminum coupons, the "trip to Mars" spores experienced space vacuum, cosmic and extraterrestrial solar radiation, and temperature fluctuations, whereas the "stay on Mars" spores were subjected to a simulated martian environment that included atmospheric pressure and composition, and UV and cosmic radiation. The survival of spores from both assays was determined after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110?nm) as well as the martian UV spectrum (λ≥200?nm) was the most deleterious factor applied; in some samples only a few survivors were recovered from spores exposed in monolayers. Spores in multilayers survived better by several orders of magnitude. All other environmental parameters encountered by the "trip to Mars" or "stay on Mars" spores did little harm to the spores, which showed about 50% survival or more. The data demonstrate the high chance of survival of spores on a Mars mission, if protected against solar irradiation. These results will have implications for planetary protection considerations.     

ODYSSEY, Orbit Determination Software for the Pioneer Data Analysis

The Pioneer anomaly refers to the difference between the computed trajectories of the Pioneer 10 and 11 spacecrafts and their actual trajectories as observed through Doppler tracking. This difference has been described by the Jet Propulsion Laboratory (JPL) as a constant anomalous acceleration. In order to perform an independent analysis, specific trajectography software, named ODYSSEY, has been developed. The paper will focus on the models implemented in this software and on the results obtained. The existence of a constant anomalous acceleration is confirmed with properties similar to those reported by JPL. Time dependent components of the anomaly are also found and discussed.     

A high-order SPH method by introducing inverse kernels

The smoothed particle hydrodynamics (SPH) method is usually expected to be an effi-cient numerical tool for calculating the fluid-structure interactions in compressors; however, an endogenetic restriction is the problem of low-order consistency. A high-order SPH method by intro-ducing inverse kernels, which is quite easy to be implemented but efficient, is proposed for solving this restriction. The basic inverse method and the special treatment near boundary are introduced with also the discussion of the combination of the Least-Square (LS) and Moving-Least-Square (MLS) methods. Then detailed analysis in spectral space is presented for people to better under-stand this method. Finally we show three test examples to verify the method behavior.     

Detection of Envisat RA2/ICE-1 retracked radar altimetry bias over the Amazon basin rivers using GPS

Altimetry is now routinely used to monitor stage variations over rivers, including in the Amazon basin. It is desirable for hydrologic studies to be able to combine altimetry from different satellite missions with other hydrogeodesy datasets such as leveled gauges and watershed topography. One requirement is to accurately determine altimetry bias, which could be different for river studies from the altimetry calibrated for deep ocean or lake applications. In this study, we estimate the bias in the Envisat ranges derived from the ICE-1 waveform retracking, which are nowadays widely used in hydrologic applications. As a reference, we use an extensive dataset of altitudes of gauge zeros measured by GPS collocated at the gauges. The thirty-nine gauges are spread along the major tributaries of the Amazon basin. The methodology consists in jointly modeling the vertical bias and spatial and temporal slope variations between altimetry series located upstream and downstream of each gauge. The resulting bias of the Envisat ICE-1 retracked altimetry over rivers is 1.044 ± 0.212 m, revealing a significant departure from other Envisat calibrations or from the Jason-2 ICE-1 calibration.     

自动化纤维铺放制造碳预型件的实时认证

为降低成本,人们正在研发像三维编织结构、三维编织物或纤维铺放等可以生产预型件后再浸胶的材料。该类技术的主要优势在于三维结构直接由一维原材料碳纤维纱线制成。这样就可以不受纤维束二维构型的约束,而是在设计预型件时考虑最终零件上的载荷,即可达到更高的性能。     

EB~2:一种新型复合材料装配解决方案

复合材料在航空领域的大量使用带来了新的技术问题,由于这些材料的性能与"标准"金属不同,特别是要关注其损伤部位,因此重新考虑安装技术以获得有吸引力的机械性能、并使之相对易于操作是很有必要的。基于以上考虑,在阿基坦大区的支持下,Capaero与WCIE(西岸产业欧洲)和Bordeaux的LGM2B实验室一起针对机械工程和材料提出了这种EB2工艺方法。     

Impact analysis of the transponder time delay on radio-tracking observables

Accurate tracking of probes is one of the key points of space exploration. Range and Doppler techniques are the most commonly used. In this paper we analyze the impact of the transponder delay, $i.e$. the processing time between reception and re-emission of a two-way tracking link at the satellite, on tracking observables and on spacecraft orbits. We show that this term, only partially accounted for in the standard formulation of computed space observables, can actually be relevant for future missions with high nominal tracking accuracies or for the re-processing of old missions. We present several applications of our formulation to Earth flybys, the NASA GRAIL and the ESA BepiColombo missions.