A CubeSat-payload radiation-reliability assurance case using goal structuring notation

• Published in: 2017 Annual Reliability and Maintainability Symposium (RAMS) pp. 1 - 8
• Main Authors: Austin, Rebekah A., Mahadevan, Nagabhushan, Sierawski, Brian D., Karsai, Gabor, Witulski, Arthur F., Evans, John
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2017
• Subjects: COTS; CubeSat; Goal Structuring Notation; Microcontrollers; Protons; Radiation Hardness Assurance; Random access memory; Reliability; Reliability and Maintainability; Single event upsets; Space vehicles
• DOI: 10.1109/RAM.2017.7889672

CubeSats have become an attractive platform for universities, industry, and government space missions because they are cheaper and quicker to develop than full-scale satellites. One way CubeSats keep costs low is by using commercial off-the-shelf parts (COTS) instead of space-qualified parts. Space-qualified parts are often costlier, larger, and consume more power than their commercial counterparts precluding their use within the CubeSat form-factor. Given typical power budgets, monetary budgets, and timelines for CubeSat missions, conventional radiation hardness assurance, like the use of space-qualified parts and radiation testing campaigns of COTS parts, is not practical. Instead, a system-level approach to radiation effects mitigation is needed. In this paper an assurance case for a system-level approach to mitigate radiation effects of a CubeSat science experiment is expressed using Goal Structuring Notation (GSN), a graphical argument standard. The case specifically looks at three main mitigation strategies for the radiation environment: total ionizing dose (TID) screening of parts, detection and recovery from single-event latch-ups (SEL) and single-event functional interrupts (SEFI). The graphical assurance case presented makes a qualitative argument for the radiation reliability of the CubeSat experiment using part and system-level mitigation strategies.