If you want a simulation you'll have to look at games such as I-War, Freespace is very much an action game in the mould of Descent and remains the best set in space I can personally recall. The scope of the battles is truly impressive, with huge capital ships slowly drumming one another whilst the fighters and bombers zip around doing their best to help turn the tide of battle.
The singleplayer experience, the sole reason for my affection, is infused with both variety and drama and I like to consider it the Half-Life of space games for how it compels you to care about the plot which unravels as you play the game. Comes highly recommended.