Johnson Space Center

The principal facility for oversight and operations of crewed spaceflight by the National Aeronautics and Space Administration (NASA).


As early as 1957, engineers and scientists at the Langley Aeronautical Laboratory at Hampton, Virginia, were collaborating on the possibility of crewed exploration of space. With the United States rapidly increasing the number of planned space missions, the National Aeronautics and Space Administration (NASA) was created on October 1, 1958, to coordinate the rapidly expanding U.S. space program and to consolidate the various space projects under one civilian agency. Realizing that crewed space missions would be much more complex and challenging than uncrewed missions, on November 4, 1958, NASA created a special task force, called the Space Task Group (STG), to deal with the issues of crewed spaceflight. The STG was based at Langley but was charged with oversight of the crewed spaceflight. STG’s first crewed space program was Project Mercury. In May of 1959, STG was made one of six departments of the newly formed Goddard Space Flight Center, in Greenbelt, Maryland. Because of STG’s rapid growth during this period, however, STG never physically moved to Goddard. On March 1, 1961, STG was made an independent entity within NASA.

On May 25, 1961, President John F. Kennedy made public a challenge and a goal for NASA to send a crewed mission to the Moon. This was an enormous jump from Project Mercury, and it required a major expansion of the roles, duties, and personnel associated with the STG. With the expansion of the STG to such levels, NASA administrator James Webb created the Office of Manned Space Flight, a special NASA division that included STG. One of the first goals of the new Office of Manned Space Flight was to secure a location for a new NASA center dedicated to crewed space missions. Cape Canaveral, NASA’s primary launch facility, was also a military missile test facility, and the Langley site was not fully suitable for expansion to include all of the facilities envisioned for the new center.

The selection of a permanent site for the new NASA center near Houston, Texas, was not without contention. Many NASA personnel wanted the new center to be either in California, near the Jet Propulsion Laboratory, or in Florida, near the launch facilities. Most of the STG team at Langley preferred establishing a facility adjacent to or near Langley. Pressure from then-vice president Lyndon B. Johnson and Speaker of the House Sam Rayburn, both of Texas, together with several influential Texas legislators, caused NASA to consider a more centrally located site. Longtime associates of Johnson at Humble Oil finally helped the Houston site to win NASA’s favor. Humble Oil donated 1,000 acres of land to Rice University in Houston, with the stipulation that the land be made available to NASA. Although land costs were not a major issue, it would not have been prudent for NASA to turn down the offer of free land for the center, especially in light of the political pressure placed upon the agency to locate a major NASA center in Texas.

Thus, on September 19, 1961, NASA announced that the new center would be located on the outskirts of Clear Lake City, a suburb of Houston. On November 1, 1961, the new NASA installation became officially designated the Manned Spacecraft Center (MSC), at which time the STG ceased to exist as a separate entity and was absorbed into the new center. Some operations began at once in leased office spaces in the Houston area, and, on March 1, 1962, Robert Gilruth, director of the new MSC and former head of the STG, moved his headquarters to Houston, officially making the MSC an operational NASA center. MSC was formally opened in February, 1964.

Construction on Mission Control began soon after the Houston site was selected, and MSC’s Mission Control served as the backup command center for the Gemini 2 and Gemini 3 missions, the first crewed Gemini missions. Beginning with the Gemini 4 mission in June of 1965, Mission Control in Houston has acted as the principal mission-command center for all U.S. crewed space missions.

Astronaut training facilities were constructed at MSC to prepare the astronauts for the conditions that they would face in space travel. Spacecraft were designed and tested at MSC, and the Lunar Receiving Laboratory was constructed to house and study the Moon rocks returned to Earth by the Apollo astronauts. Nearly adjacent to MSC was Ellington Air Force Base, later renamed Ellington Field after it was decommissioned by the Air Force, where training aircraft were kept for the astronauts. On February 17, 1973, the Manned Space Flight Center was formally renamed the Lyndon B. Johnson Space Center (JSC) in recognition of the late President Lyndon B. Johnson, his role in the Houston site’s selection, and his support for crewed spaceflight.

Mission Control

The Mission Control Center (MCC) is the part of JSC with which the public is most familiar. Mission Control occupies a prominent building, designated Building 30, near the center of JSC. On the first floor of the MCC, advanced computer systems analyze the telemetry data collected during crewed space missions. The most visible part of the MCC is the Flight Control Room (FCR). There are actually several FCRs in the MCC. Nearly identical FCRs exist on the second and third floors, with the third floor FCR used primarily for military missions. Down the hall from the primary space shuttle FCR is a slightly different FCR used for the International Space Station (ISS) operations. The FCR consists of rows of flight-control consoles facing a large display at the front of the room. Each flight-control position has computer screens and other readouts, and the controller at that position is responsible for monitoring a specific part of the mission. The lead flight control position is that of the flight director, who is ultimately responsible for all decisions related to the mission. Although the FCRs are the most publicly visible part of the MCC, they are only a small part of Mission Control. Each flight-control position is assisted by a team of engineers and technicians, many of whom work in small rooms adjacent to the FCR.

Training Systems

To prepare astronauts for the various situations to be encountered in spaceflight, numerous training facilities were built at the Johnson Space Center and at nearby Ellington Field. Some of these facilities, such as a large centrifuge built to simulate the high accelerations experienced on liftoff, were built for the Gemini and Apollo missions and were later dismantled to make room for space shuttle training systems. Other training systems include mock-ups of the various spacecraft used in crewed spaceflight. The mock-ups were used as simulators to train astronauts to deal with various situations that they would encounter in space travel. The space shuttle simulators are still used.

A Space Environment Simulation Laboratory (SESL) was constructed at MSC/JSC. The SESL consists of several chambers that are designed to reproduce the environment experienced by astronauts and equipment in space. The atmospheric pressure within the chambers can be reduced to that of a vacuum, and high intensity lamps and other electromagnetic radiation sources can be used to simulate the radiation environment in space. These chambers were used to test spacecraft, equipment, and space suits. The SESL can also be used to train astronauts to deal with the difficulties faced by such harsh environments.

To simulate the near-weightless conditions of spaceflight, JSC constructed a Neutral Buoyancy Training Facility (NBTF) at Ellington Field. The NBTF consists primarily of a very large tank of water. Astronauts wearing space suits and equipment are weighted to have a buoyancy equal to their weight. This simulation of weightlessness gives astronauts a chance to practice working and handling equipment in such an environment. A smaller but similar facility, the Weightless Environment Training Facility (WETF), where the centrifuge used to operate, was constructed in the early days of the space shuttle program.

Aircraft Operations

The Johnson Space Center operates several aircraft from Ellington Field. Some of these aircraft are used for astronaut training, and others are used in support of JSC’s mission as lead NASA center for crewed spaceflight operations. One of JSC’s training aircraft is a KC-135A transport aircraft, known as the “Vomit Comet,” which flies parabolic arcs that yield a few seconds of near-zero-gravity environment inside the aircraft. The KC-135A is used to train astronauts and perform experiments at very low gravity in a manner far superior to that of the NBTF. Unfortunately, it is unable to maintain a low-gravity environment for more than a few seconds at a time, so many parabolic arcs are needed per flight.

Many of the astronauts act as pilots for their spacecraft. These astronauts must keep current in flight training. JSC maintains T-38 jet trainers at Ellington to allow the astronauts to train in high-performance aircraft. Furthermore, at least one of the T-38 trainers is fitted with control systems that mimic the very sluggish and difficult flight controls of the space shuttle. Pilot astronauts can use this trainer to practice the maneuvers needed to pilot the space shuttle to a safe landing.

In addition to the training aircraft at Ellington, JSC also is the home to a very large turboprop cargo aircraft called the Super Guppy. This aircraft has a cargo bay 25 feet tall, 25 feet wide, and 111 feet long. It is used to transport large pieces of equipment, such as ISS components. A similar aircraft, nicknamed the Pregnant Guppy, carried components of the Saturn rockets used in the Apollo missions.

Lunar Receiving Laboratory

In 1967, construction began on a special laboratory at MSC designed to handle the Moon rocks expected to be brought back to Earth by the Apollo astronauts. Not knowing at the time whether the Moon had any indigenous life, NASA constructed the laboratory with special safeguards designed to prevent any cross-contamination of the Moon rocks with the Earth environment. Although it was soon determined that there is no life on the Moon, this sterile laboratory environment permits researchers the opportunity to analyze Moon rocks without accidentally contaminating them with Earth material. Although the last Moon mission returned to Earth on December 19, 1972, NASA maintains the Lunar Receiving Laboratory as a repository for the precious Moon rocks brought back to Earth. Facilities were constructed at the laboratory to analyze the geological properties of the Moon rocks and to study any life-forms that may exist in them.

Because the Lunar Receiving Laboratory was designed to study Moon rocks without contaminating them with Earth material, it was natural for scientists to think of using the same laboratory to study meteorites found on Earth. Numerous meteorites found during the late 1970’s and 1980’s were sent to JSC’s Lunar Receiving Laboratory for study. Among these meteorites, one called ALH-84001 created a great deal of excitement when researchers at JSC, working with scientists at Stanford University, announced in 1996 that ALH-84001 appeared to be a piece of the planet Mars thrown loose during a giant meteorite impact on that planet long ago. Furthermore, these researchers announced findings that indicated that this meteorite may contain fossil remains of Martian life. These findings remain in doubt, but it is clear that the unique facilities of the Lunar Receiving Laboratory present an ideal location to study extraterrestrial samples.


  • Bilstein, Roger E. Stages to Saturn: A Technological History of the Apollo/Saturn Launch Vehicles. Washington, D.C.: Government Printing Office, 1996. A history of the development of the Saturn rockets, with some information on support activities at JSC.
  • Dethloff, Henry C. Suddenly Tomorrow Came: A History of the Johnson Space Center. Washington, D.C.: Government Printing Office, 1993. A very thorough and readable account of the history of operations at JSC from its founding until 1993.
  • Johnson Space Center. Mission Control Center. Houston, Tex.: Johnson Space Center, 1993. A NASA Fact Sheet with information on the layout, organization, and operations of JSC’s Mission Control.
  • Shepard, Alan, and Deke Slayton. Moon Shot: The Inside Story of America’s Race to the Moon. Atlanta, Ga.: Turner, 1994. A narrative from the astronauts’ point of view of crewed spaceflight and the associated training for space missions, with a chapter on the selection of Houston as the site of the MSC.

Apollo Program

Crewed spaceflight

National Aeronautics and Space Administration

Space shuttle


“Vomit Comet”