Komarov, the old Russian astronaut, is based on Vladimir Mikhaylovich Komarov, an Air Soviet Colonel who died inside the capsule Soyuz 1 when it crashed on Earth, due to an error in the parachute opening system.
The character of Felix Cadecq (played by 'Manuel Solàs') is a tribute to the real science fiction writer Philip K. Dick, and his lecture at the Sci-Fi Congress is based on the famous lecture K. Dick did in Metz (France), 1977.
Tony and Néstor, the psychiatrist, mention quite a few times brainwashing, a mental control technique, frequently used by 20th Century totalitarian regimes and applied on numerous occasions (and, usually, in an illegal way) to the reprogramming for liberated patients of coercive sects.
WARP factor is the unity for Curvature Speed used in the Star Trek's fictional world, where WARP 1 factor equals light speed and 9,975 WARP factor, means 902.519 times light speed. Supposedly, WARP 10 is unattainable, and that's the main argument between the Sci-Fi lovers at the DVD-Video store sequence.
Goknur, the Cappadocian, practices the dervishes' turning, characteristic in Mevlevis', or Whirling Turkish Dervishes, who use this physical method in order to get in trance and reach religious ecstasy.
Tony's commentary about the Variable Specific Impulse Magnetoplasma Rocket, developed by Dr. Franklin Chang-Diaz, refers to the known motor VASIMIR, invented by a homonym American astronaut and which was capable of surpassing current spacecrafts speed.
On his second outer space trip, Tony sets ashore Io, one of the four biggest satellites of Jupiter. Io, gives name to one Zeus' lover in Greek mythology and to a mysterious alien character from PROXIMA, too.
In 2016 (ten years after the filming) astronomers from the Queen Mary University of London found clear evidence of a planet orbiting Proxima Centauri. The planet, a little more massive than the Earth, has a temperature suitable for liquid water to exist on its surface. It coincides both in location and characteristics to the planet featured and visited in this movie.