What makes science fiction "hard" is a respect for logic and adherence to the known laws of physics, versus "soft" science fiction which assumes we can innovate around any limitation (often including holes in a plot). Hardness is pretty subjective (just check out the debates on Reddit), but this list includes series that are generally seen to qualify.
Following the destruction of the Twelve Colonies of Kobol by the Cylons, a rag-tag fugitive fleet of the last remnants of mankind flees the pursuing Cylons while simultaneously searching for their true home: Earth.
Terrific premise--a Western-themed amusement park populated by robotic hosts where guests can live out their fantasies. The show is ambitious--tackling lots (too many?) Big Questions and delivers visually stunning special effects. Like Game of Thrones, the series relies on production value to compensate for sub-par writing as the seasons move on.
A police detective in the asteroid belt, the first officer of an interplanetary ice freighter and an earth-bound United Nations executive slowly discover a vast conspiracy that threatens the Earth's rebellious colony on the asteroid belt.
When a full-scale war is engaged by the evil Scarran Empire, the Peacekeeper Alliance has but one hope: reassemble human astronaut John Crichton, once sucked into the Peacekeeper galaxy through a wormhole.