The term "hard sci-fi" doesn't indicate difficulty of the material to understand, but rather how closely a work attempts to consider and abide by realism and laws of physics in the science fiction. Besides Kerbal Space Programs and the realistic space warfare simulator Children of a Dead Earth, space games that attempt hard sci-fi mechanics are incredibly rare. But the in-development Delta V: Rings Of Saturn looks to be the next game in that category, placing you at the thruster controls of a mining vessel within the titular rings.

Don't expect Rings of Saturn to be a galaxy-spanning space sim; in fact, interplanetary flight, docking, repairs, and so on are handled off-screen; the scope of the game is focused on its namesake: navigating with LIDAR and mining within the rings of Saturn, with a Newtonian flight model modulating your movement and the fuel rods of your nuclear reactor engine needing to be managed to maintain energy. Complementing the real-time mining is the management of your ring excavation company, hiring crew and buying or renting ships.
Careful "ring flight" in your civilian mining vessel is all precise thruster maneuvering, rotating and strafing to position your ship and then using mass drivers (compensate for the recoil too) and lasers (engine turbine and ultracapacitor upgrades needed to handle the power drain) to gather chunks of ice for cargo. You won't be alone though, so managing engine output and aiming so that you d...