In the 2018 IEEE International Conference on Software Quality, Reliability and Security Companion DOE Chair Vaughn Standley was first author on an article titled "Space-based Unidirectional Networks and Resiliency". In the article the authors explore how the bidirectionality of networks makes them resilient, but also vulnerable to propagating failures from cyber attacks. Unidirectional systems are mostly immune to cyberattack. The radio navigation component of the Global Positioning System (GPS) is unidirectional. However, it may be assessed as a bidirectional network when it is used to provide equivalent information in place of terrestrial networks that have failed. GPS thus serves as a case study for a novel mathematical formulation of the contribution of space-based unidirectional systems to the resilience of strategic cyber networks.