No monthly subscription. One you buy the game you own it and can play it (minus any DLC they come out with.)

But you can also buy a limited number of UEC (in game currently) per money with real money. This is to 1) combat gold farmers and 2) allow people who work full time jobs who only want to play every now and then to be able to play and not take forever to earn a larger ship.

But that is the extent of their P2W model. Anything you can buy with real money NOW you can buy with in game currency later when the game launches.

There is an optional subscription currently that gives you insider information (jump point magazine) and a special forum for donators to post in. There is no info on if that subscription will survive to the game release though. My guess is it probably will.

Supposedly they are NOT balancing the game so that you need to use micro transactions to keep up. They are just allowing you to buy a very limited amount of UECs every month. We wont know exactly how that works until they launch though.