It's like you would play an RPG.
I(the GM) post the situation. Each player will be assigned commands, that might be ships, marine units or independent fighter squadrons, just for an example.
Then, each player has a time to send the orders for his units. The statistics to be used are those here at the site. I would make a battlefield if i had enough graphic skills for making one and update it every turn, so we would have to go with a x,y,z system until i could manage to do it in a graphical way.