CCP Games' immersive, and utterly humongous, space MMO has been free-to-play for a while now, thanks to its "alpha clones" system. It's akin to an unlimited free trial featured in the likes of ...

No Man's Sky's redemption arc showcases the game's evolution into one of the best space exploration games. Star Wars: Squadrons offers solid space battles with stunning visuals and a strong community.

It's built on some aging tech, but it makes the most of Valve's GoldSRC engine ... but you can still play the original for free. If you're into Destiny's high-tech space opera but are looking ...

That also means they wouldn’t be free to destroy other engine parts. Of course, this is all theoretical at the moment. Creating an actual nuclear space engine will take more research and time.