Free. Reservations are required for the architectural tour.
Ninety-minute architectural tours depart 551 S. Hill Ave. at 10:30 on the fourth Thurs. of the month, Jan.-June and Sept.-Oct., and on the third Thurs. in Nov. No tours on holidays or during winter break. JPL tours lasting 2.5 hours are offered once a week generally at 1; reservations must be made a minimum of 3 weeks in advance.