Does it cost money to play Star Atlas?

I'm curious, does playing Star Atlas come with any financial commitment? Is there a fee associated with accessing the game, or are there any in-game purchases that are mandatory for progression? As someone who's interested in exploring the virtual universe of Star Atlas, I'd like to know if I need to set aside a budget specifically for this experience. Additionally, are there any ways to earn in-game currency or items without spending real money, or is it strictly a pay-to-play model?