Who is Saxifrage 'Sax' Russell from Red Mars and what is their importance?

Saxifrage Russell is one of the American colonists who arrives on the Ares as part of the first hundred. As a physicist, he is well respected and considered a genius. As a person, however, Sax has little social skills and is often sees as stand-offish, nerdy, and socially inept. On Mars, Sax quickly becomes the unwitting leader of the Green movement, or the movement who believes firmly in the terraformation of the planet for Earth use.