The story of Planetes takes place in the near future. Special care was given in Planetes for a very realistic depiction of space and space travel. For instance, when in a weightless environment, the frame count dramatically increases in order to make weightless motion more fluid and realistic. Also, spaceships make no noise in the vacuum of space and astronauts routinely suffer from known space illnesses such as radiation poisoning, decompression sickness, cancer, brittle bones and mental illnesses spawned from isolation in the vacuum of space.
Concepts like momentum in weightlessness are early plot points and are always illustrated naturally. Director Goro Taniguchi stated in the DVD commentary that he learned much about orbital mechanics in the course of making the series. This can be shown in showing specific orbital energy, through changing orbits by applying thrust throughout the series. Even the necessity for the retrieval of space debris that is central to the plot is rooted in the serious and growing problem with space debris today.
The show also works to connect itself to the history of rocketry and space flight. The opening sequence is similar to the television series Star Trek: Enterprise, featuring a montage of the history of space flight from Greek mythology to the "modern" setting outlined in the series. Along the way, animated images of important milestones in space travel like Robert Goddard's early rocket tests, the V-2 rocket, Sputnik 1, Laika the dog, the Vostok spacecraft, Apollo 11, Skylab, Mir, the International Space Station and the Space Shuttle Endeavour and other milestones are displayed. References to early pioneers in rocketry like Konstantin Tsiolkovsky, Robert H. Goddard, Wernher von Braun and Hermann Oberth are also made regularly.
