Japan's main space operations facility is open to the public, and it is more impressive than you might expect from a working government research center. The Space Dome exhibition hall displays a full-scale model of Japan's Kibo experiment module (the Japanese contribution to the International Space Station), a replica of the H-II rocket, and a collection of space suits, satellites, and reentry capsules. Staff give free guided tours in Japanese, with English self-guided options available.
The center is a 20-minute bus ride from Tsukuba Station. Admission is free. Closed Mondays and some national holidays — check the JAXA website before visiting.