 | Anatoly M. Sagalevitch | ... | Himself, MIR chief pilot / Keldysh expedition leader (as Dr. Anatoly M. Sagalevitch) |
| Genya Chernaiev | ... | Himself, MIR pilot |
| Victor Nischeta | ... | Himself, MIR pilot |
| Pamela Conrad | ... | Herself, Astrobiologist, JPL |
| Arthur 'Lonne' Lane | ... | Himself, Astronomer / planetary scientist (as Dr. Arthur 'Lonne' Lane) |
| Jim Childress | ... | Himself, Marine Animal Physiologist, UC Santa Barbara (as Dr. Jim Childress) |
| Dijanna Figueroa | ... | Herself, Marine Animal Physiologist, UC Santa Barbara |
| Michael Henry | ... | Himself, Marine Animal Physiologist, UC Santa Barbara |
| Kevin Hand | ... | Himself, Planetary Scientist, Stanford University / SETI Institute) |
| Maya Tolstoy | ... | Herself, Marine Seismologist Lamont-Doherty Earth Observatory of Columbia University |
| Loretta Hidalgo | ... | Herself, President Space Generation Foundation |
| Kelly Snook | ... | Herself - Planetary scientist, NASA |
| Megan McArthur | ... | Herself, NOAMA Astronaut, NASA (as Dr. Megan McArthur) |
| Tori Hoehler | ... | Herself, Astrobiologist, AMES (as Dr. Tori Hoehler) |
| Charles Pellegrino | ... | Himself, Science observer |
| Dr. Michael Atkins | ... | Himself, Science observer |
| Christina Reed | ... | Herself, Science coordinator & science observer |
| David L. Dubois | ... | Himself, Senior reserch assistant, Woods Hole Oceanographic Institution |
| Dr. Ricardo Santos | ... | Himself, Science observer for the government of Portugal |
| James Cameron | ... | Himself |
| rest of cast listed alphabetically: |
| Melanie Miller | ... | Dancer |
| Maritza Graciela | ... | Mission Control Engineer (uncredited) |
