Metrological traceability of carbon dioxide measurements in atmosphere and seawater

The accurate determination of gaseous pollutants is fundamental for the monitoring of the trends of these analytes in the environment and the application of the metrological concepts to this field is necessary to assure the reliability of the measurement results. In this work, an overview of the activity carried out at Istituto Nazionale di Ricerca Metrologica to establish the metrological traceability of the measurements of gaseous atmospheric pollutants, in particular of carbon dioxide (CO2), is presented. Two primary methods, the gravimetry and the dynamic dilution, are used for the preparation of reference standards for composition which can be used to calibrate sensors and analytical instrumentation. At present, research is carried out to lower the measurement uncertainties of the primary gas mixtures and to extend their application to the oceanic field. The reason of such investigation is due to the evidence of the changes occurring in seawater carbonate chemistry, connected to the rising level of CO2 in the atmosphere. The well established activity to assure the metrological traceability of CO2 in the atmosphere will be applied to the determination of CO2 in seawater, by developing suitable reference materials for calibration and control of the sensors during their routine use

CFD Simulation in Support of SPARTAN Research Program

none7noneD.Pavarin; M.Pessana; A.Bettella; M.Manente; M.Lazzarin; F.Barato; N.BellomoPavarin, Daniele; M., Pessana; Bettella, Alberto; Manente, Marco; M., Lazzarin; Barato, Francesco; N., Bellom

Mini RF-helicon-double-layer plasma thruster requirements for new space mission

This paper presents the feasibility study of mission analysis performed to evaluate the requirements of the thruster developed in the HPH.com (Helicon Plasma Hydrazine. Combined Micro) project, for its application onboard of a microsatellite. HPH.com is a project funded by the European Committee within the EU 7th Framework Programme and carried on by an International consortium. Objective of this program is to design, optimize and develop a prototype of a space helicon-based plasma thruster by deep numerical/theoretical investigation and extensive experimental campaign. The thruster is especially conceived to be used on board a microsatellite for attitude and position control in order to allow low-cost demonstration-mission. In order to define the requirements of such a kind of system, numerical simulations of possible mission scenarios of a microsatellite have been deeply analysed. To achieve this aim, the University of Bologna, in collaboration with Thales Alenia Space, Torino and the University of Padua developed a highly accurate orbital and attitude simulation software. The possibility to easily scale dimensions and performance of this type of thruster gives the chance to consider a large number of different missions with different goals and operative regimes from LEO to GEO. In particular a LEO low cost mission to test the thruster prototype performance has been considered and it has been developed a strategy to calculate, with an error of 10% the thrust, combining the results of simulations with optical observations from ground. This new method depicted in the paper for thrusters performance in orbit analysis is applicable to any spacecraft. Moreover we report also the mission analysis relevant to a potential innovative application for this thruster for the active debris removal (ADR). For this kind of missions both the ascent phase of a cleaner satellite from the coasting orbit to the debris orbit and the descent phase with the debris attached to the satellite have been simulated. It has been considered a debris of about 500kg in the orbits of 800 and 1400 km. Many simulations have been carried out at different thrust levels, to evaluate the trade-off between thrust and time required for the mission. The diminution of the debris mechanical life time has also been evaluate in compliance with the Inter-Agency Space Debris Coordination Committee (IADC) guidelines. The paper firstly presents a general overview of the HPH.com research project, then the methodology and the results obtained to evaluate the requirements on thruster performance, the mass budget and the power required for the thruster and in the last an overview of different feasible mission scenarios. Copyright ©2010 by the International Astronautical Federation. All rights reserved