In 'The Martian', what is the name of the commander of the Ares III mission?

In The Martian, the commander of the Ares III mission is Melissa Lewis.

Played by Jessica Chastain in the 2015 film, Commander Melissa Lewis is a NASA astronaut and the leader of the Ares III crew. She is responsible for decisions during the mission’s surface operations on Mars, including the emergency evacuation after a severe dust storm damages the Mars Ascent Vehicle. Mark Watney is struck by debris and presumed dead, forcing Lewis to order the surviving crew to leave the planet.

The Ares III crew travels aboard the Hermes, an interplanetary spacecraft that carries them between Earth and Mars. Lewis’s leadership becomes especially important after NASA discovers that Watney survived. Although the crew has already begun its return journey, she and the others must weigh mission safety against the possibility of rescuing their stranded crewmate.

The listed alternatives are members of the same mission but hold different roles. Rick Martinez is the pilot, Beth Johanssen is the systems operator, and Mark Watney is the botanist and mechanical engineer stranded on Mars. Lewis’s fondness for 1970s disco music is also a recurring character detail in the film.