Already happening. The limitation of light speed is not real unless
1. There is no wormhole infrastructure between the two destination points
2. You have meat/doll body civilizations
The propulsion engines NASA uses are mostly a spook. That's like using steam power to get to space. No one uses that trash, the physical UFOs use an antigravity propulsion system that's been reverse engineered from the crash retrievals that started in the 40's.
You don't want to get a Mars assignment if you work for the military, you'd ideally want to go to the japan or Hawaii base and barring that, somewhere in Texas or somewhere. Shit sucks balls.