Seth

Seth is the captain of Perihelion’s crew, and is one of Iris’ parents. He is tall, has very dark skin, and has no hair on the front half of his head. Martyn is his marital partner.

Although Seth is designated as the captain in Chapter 20 of Network Effect, the command structure on Perihelion seems relatively informal. Iris calls Seth "Dad" and seems comfortable arguing with him about proposed actions while they are on a mission.