UPGRADE OF THE ESA DRAMA OSCAR TOOL: ANALYSIS OF DISPOSAL STRATEGIES CONSIDERING CURRENT STANDARDS FOR FUTURE SOLAR AND GEOMAGNETIC ACTIVITY

摘要

In 2008 the UN General Assembly adopted resolutionrn62/217, endorsing the space debris mitigation guidelinesrn(SDMG) of the UN Committee on the Peaceful Usesrnof Outer Space (UNCOPUOS). These guidelines containrnrecommendations for satellite operators to implementrnmeasures for various mission phases in order to reducernthe further accumulation of space debris in spacernand especially within the protected regions. These arerndefined within the SDMG as being the LEO region (up torn2,000 km altitude) and the GEO region (u0006200 km in altitudernaround the GEO altitude and u000615 degrees latitude).rnIn the first version of ESA’s DRAMA tool suite, OSCARrn(Orbital SpaceCraft Active Removal) was designed as arntool to allow users the analysis of different disposal stragiesrnfor spacecraft in the LEO and GEO region. Thernupgrade of the ESA DRAMA tool suite by TUBS andrnDEIMOS under ESA/ESOC contract included the developmentrnof a renewed version of the existing OSCARrntool, allowing in its current version the consideration ofrndifferent future solar and geomagnetic activity scenariosrnand besides the already known disposal systems (chemicalrnand electric propulsion, as well as electrodynamicrntether) the analysis of the orbital evolution using dragrnaugmentation devices. One of the primary goals wasrnto implement techniques recommended by current standards.rnThe recommendations from the SDMG were usedrnfor the definition of the critical regions as well as compliancerncriteria, the user may check his disposal strategyrnagainst. For satellites operating in GEO, the ISOrn26872:2010 (Space Systems - Disposal of satellites operatingrnat geosynchronous altitude) standard was accountedrnfor. For the generation of future solar and geomagneticrnactivity, the standards ISO 27852:2011 (Space Systems -rnEstimation of orbit lifetime) and the ECSS-E-ST-10-04Crn(Space engineering - Space environment) have been consideredrnand recommended modeling approaches were implemented.rnIn this paper, the OSCAR tool is presented, giving anrnoverview on the future solar and geomagnetic activityrnscenario generation, the standards involved, as well asrnthe new available disposal option of using drag augmentationrndevices. Exemplary results are shown, consideringrnthe deviations encountered when using methods proposedrnby different standards, as well as some propagationrnresults obtained with FOCUS-1A, which is the propagationrntool used in OSCAR. Further new features will bernhighlighted, for example the possibility to download upto-rndate solar and geomagnetic activity data and use it inrnOSCAR simulations, as well as the compliance checksrnprovided by OSCAR based on the SDMG.