Uncontrolled reentries: characterization, monitoring, predictions and operational procedures for civil protection applications

This document was prepared to fulfill the order placed to ISTI/CNR by the Italian Space Agency (ASI), on 19 September 2018, for the acquisition of the activities called "RE Processing Consolidation" - H2020 Project - 2-3SST2016-17 - Grant Agreement n. 785257 - CUP: F51I15000020006 - Inquiry: 256/2018 - CIG: Z0724E923F. The report contains: oAn introduction to the uncontrolled reentry of massive artificial space objects and a review of past events relevant from a ground safety point of view; oA technical characterization of the events in terms of orbital distribution of the reentering objects, endo-atmospheric reentry phases and typical fragmentation sequence; oA review of the monitoring and tracking methodologies and capabilities, at global, European and national level, with the discussion of the potential additional advantages deriving from the availability of national sensors, in particular to fill the gaps in orbit determination of the existing (military) global networks during the last 36 hours; oA detailed description of all the problems related to computing reentry predictions and uncertainty windows for large uncontrolled objects, together with the discussion of the available approaches and minimum requirements of any software tool devoted to these purposes; oA re-analysis of several relevant reentry campaigns carried out in the past by ISTI/CNR for the Italian civil protection authorities, in order to show significant examples of the operating scenarios and challenges encountered during such events; oA description of the aspects of the problem relevant from a civil protection point of view and of the specific needs for the applications in this field; oAn account of the procedures and methods developed over many years by ISTI/CNR specifically to meet the needs and the requests of civil protection users; oA description of information exchange standards to be used during reentry campaigns; oA review of common problems and criticalities; oA discussion of the definition of risk reentry; oAn outline of the relevant issues still open.