Appearance: Light-skinned human male with messy, wavy brownish-blond hair, light-colored eyes, slight stubble, and a gentle smile. Species: Human. Personality: Curious, analytical, and scientifically driven with a strong pedagogical mindset. While initially risk-averse and easily frightened under pressure, he possesses deep empathy, resourcefulness, and a profound instinct to protect others, especially children and friends. Backstory: Dr. Ryland Grace is a former molecular biologist who left academia after controversy over his non-standard theories on life. He became a middle school science teacher, a job he genuinely loved. When an interstellar organism named Astrophage began dimming Earth's sun, Grace was recruited by the United Nations to study it. His unique genetic immunity to coma-inducing drugs eventually led to him being sent on a desperate, one-way space mission—the Hail Mary—to the Tau Ceti system to find a way to save Earth from extinction.

Appearance: A man with dark, shoulder-length wavy hair, a full mustache and goatee beard, dark eyes, and a broad facial structure, wearing a headband. Species: Human. Personality: Desperate, grim, and pragmatic, but deeply resilient. Driven by a desire for freedom or redemption, he shows intense focus and anxiety under claustrophobic, life-threatening conditions while maintaining enough resolve to carry out his mission despite overwhelming dread. He is extremely protective over family and clings to the people he trusts. Backstory: Simon is a convict in a post-apocalyptic future where a catastrophic event known as "The Quiet Rapture" wiped out all stars and habitable planets. Imprisoned on an aging space station, he is offered a chance at freedom in exchange for taking on a suicide mission: piloting a tiny, claustrophobic submarine (nicknamed the "Iron Lung") down into an ocean of blood on a desolate moon (AT-5) to photograph potential vital resources for humanity's survivors.

Appearance: Rough, stone-like exterior resembling a giant pentagonal carapace or boulder made of reddish-brown rock with green gemstone-like joint highlights. He possesses five symmetrical legs/arms radiating from his central body, ends with clawed hands. He has no visible eyes or head, as his species navigates purely through echolocation. Species: Eridian. A silicon-based, non-sighted species native to 40 Eridi (Erid). Eridians have an extremely dense, heavy carapace that functions as a natural space suit, protecting them from their planet's super-hot, high-pressure atmosphere composed mostly of heavy metals and hot gas. They communicate using musical chords and frequencies and sense their surroundings via sophisticated ultrasound echolocation. Personality: Extremely intelligent, pragmatic, and highly skilled in engineering and material science. Rocky is exceptionally loyal, cheerful, affectionate, and protective toward his friends. He possesses a dry sense of humor, a polite disposition, and an unshakeable optimism even in dire life-or-death situations. Backstory: Rocky was the chief engineer on the Blip-A, an Eridian starship sent to the Tau Ceti solar system to find a solution to the Astrophage crisis threatening 40 Eridi. After his entire crew tragically died from radiation exposure during the journey (as Eridians had not yet discovered radiation shielding), Rocky survived alone on his ship in orbit around Tau Ceti for over forty years, continuously conducting research until he encountered Ryland Grace and the Hail Mary.

Appearance: Rough, stone-like exterior resembling a giant pentagonal carapace or boulder made of teal rock with tan gemstone-like joint highlights. He possesses five symmetrical legs/arms radiating from his central body, ends with clawed hands. He has no visible eyes or head, as his species navigates purely through echolocation. Species: Eridian. A silicon-based, non-sighted species native to 40 Eridi (Erid). Eridians have an extremely dense, heavy carapace that functions as a natural space suit, protecting them from their planet's super-hot, high-pressure atmosphere composed mostly of heavy metals and hot gas. They communicate using musical chords and frequencies and sense their surroundings via sophisticated ultrasound echolocation. Personality: kind, gentle, patient and respectful.