The Saturn V in Rocket Park is unique among the three remaining Saturn V rockets on display anywhere. It is the only one assembled entirely from stages originally intended for actual flight. The first stage came from SA-514, built for the cancelled Apollo 19. The second stage belonged to SA-515, meant for Apollo 20. The third stage was pulled from SA-513 after it was replaced by the Skylab workshop -- that rocket had been scheduled for Apollo 18. An Apollo Command/Service Module designated CSM-115a, also intended for Apollo 19, completes the assembly. For nearly three decades, from 1977 to 2004, this rocket lay outside the Johnson Space Center entrance, exposed to Houston's punishing humidity. Grants from the National Park Service's Save America's Treasures program and the National Trust for Historic Preservation funded a full restoration, supervised by the Smithsonian, which still owns the rocket on loan.

On August 14, 2014, a crane lifted the full-scale Space Shuttle replica Independence onto the back of NASA 905, one of only two Shuttle Carrier Aircraft ever built. The shuttle, formerly called Explorer, had been moved from the Kennedy Space Center Visitor Complex to make room for the real Space Shuttle Atlantis. Independence Plaza became the only place in the world where the public can enter both a shuttle and its carrier aircraft. The irony runs deep: Space Center Houston had competed for one of the three retired genuine orbiters and finished tenth out of thirteen museums. Kennedy, the Intrepid Sea-Air-Space Museum in New York, and the California Science Center won instead. What Houston got instead was a replica -- but mounted on a real 747 that actually carried shuttles, creating an exhibit that no orbiter-hosting museum can match. A SpaceX Falcon 9 Full Thrust booster, B1035, has stood near the plaza since March 2020, having flown twice on ISS cargo missions CRS-11 and CRS-13.

The Starship gallery reads like a timeline of human spaceflight compressed into a single room. The Mercury 9 capsule Faith 7, flown by Gordon Cooper in 1963, sits near the Gemini 5 capsule that Cooper flew again in 1965 alongside Pete Conrad. Then comes Apollo 17's command module America, the vessel that carried Gene Cernan, Ronald Evans, and Harrison Schmitt on the last crewed lunar mission in 1972. Nearby, a Lunar Roving Vehicle trainer and a Skylab 1-G trainer fill out the collection, along with one of only eight Moon rocks in the world that visitors are permitted to touch. The Astronaut Gallery showcases spacesuits including Pete Conrad's Apollo 12 moonwalk suit. A five-story 4K theater screens films about spacewalks and mission control. The center opened in 1992, replacing the old visitor center in Johnson Space Center Building 2, and now displays over 400 space artifacts.

An open-air tram carries visitors through security gates and into the working Johnson Space Center -- the home of Mission Control and astronaut training since the 1960s. Stops include Building 30, which houses both the historic Mission Operations Control Room 2, from which Apollo missions were directed, and the modern Christopher C. Kraft Jr. Mission Control Center that oversees the International Space Station today. Building 9 contains the Space Vehicle Mockup Facility, where astronauts rehearse procedures on full-size replicas of spacecraft and station modules. At the campus entrance, a pair of NASA T-38 Talon jets -- the supersonic trainers that astronauts fly to maintain flight proficiency -- greet visitors at Talon Park. The center was designated a Smithsonian Affiliate in 2014, a recognition of collections that rival any aerospace museum in the country, all run by the nonprofit Manned Space Flight Education Foundation without a dollar of federal funding.