Assessing debris strikes in spacecraft telemetry: Development and comparison of various techniques.

Debris strikes on operational spacecraft are becoming more common due to increasing numbers of space objects. Sample return missions indicate hundreds of minor strikes, but rigorous analysis is often only performed when a strike causes an anomaly in spacecraft performance. Developing techniques to identify and assess minor strikes that do not immediately cause anomalous behavior can help to validate models for debris populations, perform risk assessments, and aid in the attribution of future anomalies. This study introduces debris strikes to a spacecraft dynamics simulation and assesses the effect on spacecraft telemetry. Various signal processing and change detection techniques are used to identify strikes in noisy telemetry and estimate strike parameters. Matched filter wavelets are developed to identify the effects on state telemetry, where errors are autonomously corrected by the spacecraft attitude control system. A bank of matched filters is used to estimate the parameters of the strike based on a priori knowledge of the spacecraft's response characteristics. A sequential probability ratio test is used to highlight abrupt changes in the spacecraft's angular momentum. Monte-Carlo analyses are conducted to characterize the performance of these algorithms. The results of the various techniques are compared in terms of correctly identifying the debris strikes and accurately estimating the strike parameters. Developing the capability to catalog and characterize minor debris strikes allows any spacecraft to be used as an in situ debris sensor.