The differences were subtle, but the two probes were definitely based on slightly different designs. It came as no surprise that the Brazilians would have worked on improvements even as they were building and launching probes. Apparently the first and second probes to leave Earth had been—Oh, hold on. That would require three different launches from Earth. One to Epsilon Eridani to fight Bob-1, one to Alpha Centauri, and one to 82 Eridani. Sure enough, my memory of Bob’s Medeiros was yet a third design variant.