It is always possible to tap into your retirement savings before you retire, but just remember that doing so always leaves you with a much smaller nest egg after penalties and taxes, so it's best to avoid it altogether if possible.
It is worth noting that there are a few exceptions for withdrawing money out of an IRA. You may withdraw IRA money penalty-free for qualified education expenses, but Roth earnings are taxable in this case.
Current law also allows you to withdraw as much as $10,000 penalty-free to help buy your first home. And if are disabled or you are unemployed and need funds to cover health insurance you can tap your IRA with no penalty.