Delfi-n3Xt forensics: A hybrid methodology

In this master thesis the reader will find the application of a hybrid forensic investigation on a CubeSat project. This CubeSat, known as Delfi-n3Xt, was developed by the Delft University of Technology and it was launched in November 2013. The satellite was successfully operated for three months but contact was lost after execution of an experiment. The reader will find that the investigation is greatly affected by a lack of facts. There is no accessible physical evidence, the CubeSat wasn’t formally verified, and internal documents are lacking in many aspects. Therefore, the research methodology itself is the topic of interest and Delfi-n3Xt is used as a case-study. Due to the lack of facts, a combination of a forensic approach and a more general empirical approach is used. In this thesis, the satellite operations are reviewed extensively by inspection of orbital elements, by an extensive telemetry analysis, by a reconstruction of the mission and by a detailed analysis of the last moments of contact. Beyond the operations, the design of the ISIS Transceiver (ITRX), including the Linear Transponder (LT), is reviewed to identify hypotheses. During this thesis over 30 hypotheses were identified. Some hypotheses are directly related to the loss of contact and some are not. Since many hypotheses were identified, a selection was made for verification. This selection procedure was based on a methodology similar to a risk assessment, where the hypotheses with highest risk are selected. Eventually five verification campaigns were performed. One campaign was based on analysis and the other four were based on tests using spare hardware. Unfortunately, no root cause was found during this thesis, but two hypotheses were rejected, one hypothesis was verified, and one hypothesis was considered plausible and highly likely. Based on the achieved results it is concluded that the used methodology is effective for cases like Delfi-n3Xt, were evidence is lacking. It is acknowledged however, that full confirmation of the root cause of failure can’t, and will never be achieved, because the only way to determine the root cause is by inspection of the satellite itself. Many lessons were learned however, regarding forensics, regarding Delfi-n3Xt and regarding CubeSat projects in general.