Johnson Space Center serves as the lead NASA center for the International Space Station -- a United States-led collaborative effort of 16 nations throughout the world. JSC orbits more than 240 miles above the earth and its Mission Control Center has been the operational hub of every American human space mission since Gemini IV. The MCC manages all activity onboard the space station and directs all space shuttle missions, including station assembly flights and Hubble Space Telescope servicing. JSC is also home to the NASA astronaut corps, and is responsible for training space explorers from the United States and its space station partner nations. JSC leads NASA's flight-related scientific and medical research efforts and strives to make revolutionary discoveries and advances to benefit all humankind. Technologies developed originally for space flight have found a wide range of applications in medicine, energy, transportation, agriculture, communications and electronics. Johnson Space Center was established in 1961 as the Manned Spacecraft Center. In 1973, the Center was renamed in honor of the late President and Texas native, Lyndon B. Johnson.