The International Red Cross often finds itself providing aid and medical services to victims of disasters such as an earthquake, flood, or hurricane. It has two mobile communication systems, one using low earth orbit satellites, and the other, short antennas mounted on trucks. These two alternative communication networks are community lifelines that enable all rescue agencies and government services to communicate. The low earth orbit system is a series system with four components. Three identical satellites (components A) orbit close enough that they are assumed to operate in parallel with a reliability of 0.965 based on simulations of their digital twins. Components B, C, and D of the system have reliabilities 0.88, 0.99, and 0.90, respectively. The mobile truck and antenna-based system is also a four-component series system. Component A has a reliability of 0.95 based on simulations of their digital twins. Components B, C, and D have the same reliabilities as the low earth orbit system.

a. What is the reliability of the satellite-based system?

b. What is the reliability of the mobile truck-based system?

c. What are your final recommendations, assuming the costs of either system are roughly the same?