Building 30

Building 30 at the Johnson Space Center is Mission Control, and the reason "Houston" became the name astronauts call home. Command of American crewed flights moved here from Cape Canaveral with Gemini 4 in June 1965, the flight on which Ed White made the first American spacewalk. The building held two four-tier control rooms. The one on the third floor, Mission Operations Control Room 2, ran most of the Gemini and Apollo flights, including both of the calls that made the word famous. On 20 July 1969 the first words after touchdown on the Moon were Buzz Aldrin's "Contact light." Seconds later Neil Armstrong said, "Houston, Tranquility Base here. The Eagle has landed." Charlie Duke, the capsule communicator, answered that the room had "a bunch of guys about to turn blue."

On 13 April 1970, after an oxygen tank exploded aboard Apollo 13, Jack Swigert radioed, "Okay, Houston, we've had a problem here." Jim Lovell repeated it. The words were never "we have a problem," though that is how the line is usually quoted. The flight director on duty was Gene Kranz.

Mission Control was designated a National Historic Landmark in 1985, and the Apollo room last controlled a flight in 1992. Its consoles were shipped to the Kansas Cosmosphere for restoration in 2018, and a $5 million restoration finished in July 2019 that put it back to its Apollo-era look. The City of Webster gave $3.1 million, a public Kickstarter raised $525,000 with another $400,000 to match it, and NASA added the last $1 million. The building has carried Christopher C. Kraft Jr.'s name since 2011, and the restored room is seen from its viewing gallery on Space Center Houston's Historic Mission Control tram tour.