Commander William Norton is a highly experienced space exploration officer directing the spaceship *Endeavour*. Raised in Australia, he holds dual citizenship on Earth and Mars, maintaining separate families on each planet. As a seasoned spaceman, interplanetary travel has become routine to him, causing a sense of professional detachment and disillusionment with the solar system. The appearance of Rama presents an unprecedented challenge that forces him to reconsider his assumptions about the universe.

Jimmy is a junior officer serving under Commander Norton. Before joining the space service, he competed as a professional athlete in the Lunar Olympics, where his exposure to low-gravity flight inspired him to acquire a specialized sky-bike. He smuggles this delicate craft, dubbed "Dragonfly," onto the ship by falsely logging it as recreational equipment. His eagerness to push physical boundaries contrasts sharply with his commander's calculated prudence.

Rodrigo is the communications officer aboard the *Endeavour*. He belongs to the Fifth Church of Christ, Cosmonaut, a religious organization asserting that Jesus Christ originated from outer space. His steadfast faith often baffles Commander Norton, who expects scientific observation to conflict with religious devotion. Rodrigo views the alien cylinder through a deeply spiritual lens, theorizing it is a cosmic ark meant for salvation.

Ernst is the Surgeon-Commander and chief medical officer on the *Endeavour*. She acts as Norton's equal regarding crew health, enforcing strict fitness protocols to protect the explorers from the shifting artificial gravity. Driven by scientific inquiry, she eagerly analyzes environmental samples from the alien vessel.

The unnamed ambassador from Mercury represents his planet's interests during the United Planets sessions regarding Rama. Reflecting his settlement's cultural disposition, he exhibits intense paranoia regarding the solar system's resources. He views the alien vessel purely as an incoming hazard to human survival, advocating for preemptive, defensive strikes to protect Mercury and the sun from outside exploitation.

Mercer is the life-support officer on the *Endeavour*. He leads the initial probe teams down the vast stairways into the alien cylinder. He works methodically, testing atmospheric pressure and oxygen levels to guarantee safe conditions before allowing the crew to remove their helmets.

Lieutenant Joe Calvert serves as the pilot of the *Endeavour*. He joins multiple internal probe teams, demonstrating quick thinking when handling the cylinder's unusual artificial gravity. During the descent, he proposes using the massive stair handrails as slides to increase their travel speed.

Dr. Perera is an exobiologist advising the Rama Committee. The alien vessel's arrival thrills him, as it validates his longstanding academic theories concerning interstellar travel and space arks. He closely monitors environmental telemetry to forecast the cylinder's internal weather patterns.

Dr. Bose is the Martian Ambassador and the acting chairman of the Rama Committee. He moderates the tense discussions between various planetary ambassadors and technical specialists as they attempt to evaluate the ongoing exploration remotely.

Myron is a Technical Sergeant aboard the *Endeavour*. His mechanical expertise is crucial for interacting with alien technology, but he initially lacks the physical conditioning necessary for the rigorous climbs inside the cylinder.

Sergeant Pieter Rousseau is a reconnaissance technician aboard the *Endeavour*. Fascinated by observation, he eagerly accepts the role of remote monitor at Hub Control, watching the alien plains through a telescope and categorizing the mechanical entities that appear.

Executive Sergeant Ruby Barnes holds the most extensive sailing experience among the *Endeavour* crew. She assumes command of the makeshift raft *Resolution* to cross the toxic alien waters, proving steady when environmental conditions become turbulent.

Caroline is Commander Norton's Earth-based wife. She accepts the realities of his long deployments and maintains a polite, albeit entirely separate, dynamic with his other family on Mars.

Myrna is Commander Norton's Martian wife. Like Caroline, she manages a household independently while her husband serves in space, settling into a comfortable routine built around his extended absences.