We free the top cover, only to find…3.5" of empty space.

While the AirPort Extreme doesn't come equipped with storage, we dug up a standard 3.5" SATA hard drive, just to test it out. Perfecto!

This could potentially be good news to DIYers who want to turn their AirPort Extreme into a Time Capsule—except we can't find any connectors where we'd plug in the hard drive, only empty spaces on the logic board. But we'll keep our fingers crossed until we've had the chance to crack open a Time Capsule.