Who is Salo from The Sirens of Titan and what is their importance?

Salo is a messenger from the planet Tralfamadore, Salo is stranded on Titan when his spacecraft malfunctions because of a broken part. Salo is a machine, but has emotions that seem to run deeper than most of the human characters in the novel. He comes to love Rumfoord as a friend after helping him build up his Martian army and invent his new religion. Salo is despondent when Rumfoord disappears, and commits suicide by taking himself apart.