Stijn Lemmens

Two-Line-Elements-Based Maneuver Detection Methods for Satellites in Low Earth Orbit

Two novel methods are developed for detecting space events based on the analysis of their two-line elements history. These methods are tuned for detecting orbital maneuvers of satellites and the characterization thereof. The first method detects nonnatural anomalous events in low Earth orbit based on a consistency check between arbitrary two-line element sets of the same object. The use of background models that enable one to estimate the variable noise in the two-line element consistencies for different orbital regimes is found to further increase the detection rate. The second method uses the time series of an object containing the orbital elements, or a derived quantity thereof, and evaluates it for any type of unexpected changes by methods from robust statistics and harmonic analysis. Both methods can process the entire two-line element catalog with a minimal operator interference while yielding good results in the different orbital regimes. The generated orbital maneuvering data are used to assess th...

Global Trends in Achieving Successful End-Of-Life Disposal in LEO and GEO

Guidelines for space debris mitigation have been formulated by the IADC (Inter Agency Debris Coordination Committee) in 2002. The principal mitigation actions are the passivation of space systems after the end of operations, the limitation of the remaining post-mission dwell time in the LEO and GEO protected region and the limitation of the release of debris. In the past ten years, these recommendations and associated threshold values have been included in several national and international standards and should now be applicable to numerous new missions. Verification of the implementation of mitigation measures in the design of a mission is the responsibility of each nations’ or agencies’ project control during design reviews. The proper implementation of the measures will be followed up by the review of procedures, mission logs and reports.