Your players expect exciting space battles with flying turbolaser blasts and exploding TIE fighters. Give them those kinds of scenes.
Your starship battles should follow the same guidelines as those covering vehicle combat. It's a lot more important to create an exciting battle scene with good storytelling than to measure out every movement round-by-round.
"As you dive into the asteroid belt, your sensors tell you the TIE fighters are closing in fast. Make your space transports roll — a 15. Good! Your ship maneuvers around the asteroids just as the pair of TIE fighters turn to follow you. Let me make their starfighter piloting rolls — one fighter threads the needle, but the second pilot is a hair too late. He careens off one of the small rocks and goes spinning out of control until his ship smashes into a large asteroid, exploding in a ball of flame. Still, that first TIE fighter is closing in and it looks like he's trying to line you up in his sights! What are you going to do?"
That narration gives the players a good idea of what's going on and moves quickly; there's a minimum of number crunching. The gamemaster knows the TIE fighters are a lot faster than the freighter. He estimated that as long as the pilots rolled halfway decently, they'd be able to close in on the much slower freighter. Of course, one TIE pilot rolled really poorly and ended up colliding with the asteroids.
The players can picture the scene in their minds and know that their characters have to do something—or else their ship will get blasted to atoms.
When gamemastering space battles, use a combination of scenes, rounds, and encounters to maintain a lively pace and simulate the action shown in the movies. Bend the rules when they slow things down: set a difficulty number, have the players roll their skills, and use your judgment to determine what happens.
Starships cover thousands of kilometers per second in open space. While they are moving much more slowly when orbiting planets and maneuvering through asteroid fields, their speeds are still incredible.
Rather than use huge numbers for movement, the game uses Space units to represent ship speeds and weapon ranges. The ships always move at the same proportional speeds.
For most games, it's enough to describe the situation and let the players visualize what's going on in their minds.
If you want to provide something a little more visual, you can use counters, licensed figures, and model kits to show the relative location of each ship so the players can picture the battle.
If you want to run a very detailed game, you can map out each movement. Place each ship miniature on the table with a scale of:
1 inch = 1 Space unit
Use rulers to measure exact movements and weapon ranges.
Source: REUP:131