Some of this stuff goes without saying, but the devil is in the details when it comes RPGs. Sci-fi games are no exception. Placing the right level of nuance to the games can really make t shine.
For example, what system of measurement is being used? Imperial system? Sure. There’s no reason not to, but most actual scientific literature will be written in the metric system. While its possible to make the conversions, it may be easier to stick with metric measurements. Same goes for temperature and everything else.
Also consider narrative elements such as, what is it like to travel at light speed? Faster than light speed? Are the fun little effects that you all might describe from time to time? What about travel through asteroid fields? Can you travel at the speed of light through obstacles? What happens if you do?
While some of this may fall on the GM, the players should be encouraged to contribute as well. Shared world-building is a lot of fun and makes the game richer. This can be a topic for a another post though.
The essence of great game lies in how little quirks can add to the experience at the table. Taking into consideration like systems of measurement, or inventing scientific laws to explain odd technology can be a lot of fun. Is it necessary? No. Is it fun? Absolutely, and its the kind of thing that makes a good campaign great. Next time you and your group get together, try to brainstorm some fun little ideas you can write into the game. Over time, you’ll be able to flesh whole new realms of gaming to draw on.