Initially, ship refueling and repairs were services sold by the store. Any trip that expended resources exceeding the cost of cargo gained was a sad failure. If this encourages the player to make interesting decisions about how they find more cargo to sell, then the refuel/repair mechanic is a success.
But there are some ways in which this mechanic can fail:
1. Finding a fuel-efficient means of getting to asteroids is yet another thing the player has to learn before they experience their first success.
2. Because the only penalty for death is losing credits, it's sometimes better to die than to pay the store to repair/refuel.
Although these problems can be fixed, paying for fuel and repairs currently inflicts more frustration on new players than I'd like. For now, the mechanic has been removed, and the player's ship just automatically refuels and repairs once it touches the shop.