The sessions in Guantanamo Bay are closed to the public. But relatives who register can see them on closed-circuit television at Fort Hamilton, a U.S. Army base. Another space there is reserved for first responders.
The military commission hearings will also be shown at forts in New Jersey, Massachusetts and Maryland.
The suspects include the self-professed mastermind of the Sept. 11 attacks.
The men are expected to appear at the hearings, which are scheduled from Monday through Friday.
The actual military tribunal will not start till sometime next year.