All three are members of the First Hundred who become researchers at Acheron. Although these guys might not be knee-deep in the political scene, their list of accomplishments makes them important characters in Robinson's universe all the same.
Vlad and Ursula develop the gerontological treatment, a cellular longevity therapy that allows people to live longer by a couple hundred years. As you can imagine, the treatment changes the social and political climate of both Earth and Mars since everyone thinks this a swell idea, but not everyone gets their own slice of immortality.
Vlad and Marina research what they call "eco-economics," an economic system that measures value on caloric intake rather than money-making skills. This form of economics inspires John Boone's vision of what Mars could be and is later adopted by various groups of Martian revolutionaries.
They manage to make it to Hiroko's refuge during the final days of the revolution, where they live happily ever after—or until the sequel, whichever comes first. They also maintain an open ménage à trois relationship.
Simon is Ann's husband and Peter's father. A member of the First Hundred, Simon is reserved in speech and follows Ann around like a puppy dog lost on, well, Mars. With that said, when Ann attempts suicide, Simon saves her life and gives her a pent-up what-for regarding her selfishness.
The son of Ann Clayborne and Simon Frazier, Peter goes MIA during the destruction of the space elevator and is believed to be dead. Ann loses the will to live at the thought, but Peter actually survives. After a harrowing, if uneventful, spacewalk, Peter is rescued and brought to Hiroko's refuge, where he reconnects with his mother and father.
Zeyk and his wife, Nazik, are Muslims who emigrated to Mars from Egypt. Zeyk befriends Frank, and the two remain close despite Frank having used Selim. Zeyk and his wife both agree with Frank's assessment of social progression for the Muslim community on Mars.
Kasei is the child of John Boone and Hiroko by way of artificial insemination. Kasei is loyal to the Red cause, if a wee-bit strong-willed. With Michel, he helps drive Maya, Nadia, Ann, Simon, and Sax to Hiroko's refuge. Fun fact: Kasei is the Japanese name for the planet Mars.
Hiroko Ai smuggled this man aboard the Ares, meaning he's the secret one hundred and first person of the First Hundred. The Coyote can play hide-and-seek with the best of them, and he lives undetected in Underhill for years. He can also travel the Martian landscape with an ease that seems supernatural, a feat that gains him an air of mythic quality.
A young, eager, and—let's just say it—rather stupid young man, Frank tricks Selim into killing John Boone. But not before poisoning him, so the whole thing would look like a murder-suicide.
An American chemist amongst the First Hundred and one of Sax's few friends, Spencer developed the D16 airplanes and was a leader of MarsFirst. He survives the Martian Revolution.
Members of the First Hundred, Sasha and Yeli travel with Nadia, Ann, Simon, and later Sax during the Martian Revolution. Sasha dies during Phobos's attack on Cairo, and Yeli bites it during the subsequent assault on the city.
Samantha is another of the First Hundred and a leader of MarsFirst. During the revolution, her convoy is attacked by Phobos outside the city of Cairo. She dies along with Alex Zhalin and Evgenia.
Janet's a reporter amongst the First Hundred. Her recording of Ann and Sax's argument on terraforming convinces UNOMA to start a committee on the subject, and this ultimately leads to the first attempts to terraform the planet.
A German millionaire and UNOMA top official, Helmut is in the pockets of the transnats and begins making concessions for them a full ten years before the Mars Treaty is up for revision.
Hiroko's assistant among the First Hundred, Iwao stays and works with Hiroko throughout the novel. And guess what? Iwao doesn't speak more than two words during that time.
Etsu's the mohole director at Senzani Na. John prevents a truck from being dropped on both of them ACME safe-style.
Jürgen is a Swiss road builder on Mars. His take on the Red/Green debate over Mars impresses John and impacts his way of thinking.
A Suti John encounters in his travels, Dhu and his community's idea of a gift economy greatly influences John's ideal of Mars's future.
UNOMA investigators sent to Mars to, you know, investigate. Specifically, Sam and Chang are meant to investigate the sabotage incidents, though they end up investigating and harassing John a fair bit, too.
Hanavada and Sung are Indian and Chinese leaders, respectively, whom Frank has to negotiate with to get his version of the new Mars Treaty signed and passed.
A powerful transnat lobbyist.