Speaker
Description
Given the recent increase in space activity, new interest has been brought on understanding the consequences that in-orbit fragmentations can create to the space environment. In addition to the potential collisions that fragments produced in a breakup could have on the operational population of satellites, it is important to evaluate the increment of operational effort caused by a break-up event. This refers to the assessment of an increased number of conjunction alerts and the eventual execution of Collision Avoidance Manoeuvres (CAMs). Connecting the burden of CAM to possible fragmentation event can provide a quantitative link between short term space traffic management and long-term space sustainability.
Previous works have introduced methods for debris cloud modelling through a continuum-based approach. The STARLING 2.0 suite, developed at Politecnico di Milano, is an example of this. This tool propagates the space distribution of a debris cloud through the method of characteristics (MOC) and then uses the kinetic gas theory analogy, to estimate the impacts of the debris with other targets.
In this research, this technique is employed for propagating and estimating the conjunctions between trackable fragments and active satellites. To do this, the minimum size of modelled fragments is elevated from 1 cm to 10 cm, capturing only fragments that would be trackable. Additionally, an enlarged cross-sectional area for the evaluated targets is taken. With this, instead of detecting the collisions caused by the fragments, an estimation of close encounters is yielded. The selection of the enlarged cross-sectional area is done by defining a threshold on the miss distance. Considerations such as the time delay in the object cataloguing process after a fragmentation, and the fraction of undetected fragments are included in this method. For validation, the Cosmos-1408 fragmentation is included as a test case. The resulting number of conjunctions is used to estimate a monetary operational cost incurred by operators due to the fragmentation. This value is estimated based on an average labour hour cost and the estimated time that operators take to assess conjunction alerts. The proposed methodology, is finally used to build pre-computed consequence maps, showing the different operational consequences that breakups at different orbital bins would cause. This research is part of the TELCOLA project “T509-801SD debris impact assessment to improve collision avoidance metric for telecommunication spacecraft” funded by the European Space Agency Space Safety Programme.
| Which section would you like to submit your abstract to? | Session 5: “How to assess the impact of space missions onto the space environment?” |
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