A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 km (22,236 mi) in altitude above Earth's equator (42,164 km (26,199 mi) in radius from Earth's center) and following the direction of Earth's rotation.

An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963.

Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas (located on Earth) do not have to rotate to track them but can be pointed permanently at the position in the sky where the satellites are located. Weather satellites are also placed in this orbit for real-time monitoring and data collection, and navigation satellites to provide a known calibration point and enhance GPS accuracy.

Geostationary satellites are launched via a temporary orbit, and placed in a slot above a particular point on the Earth's surface. The orbit requires some stationkeeping to keep its position, and modern retired satellites are placed in a higher graveyard orbit to avoid collisions.



The 1964 Summer Olympics (Japanese: 1964年夏季オリンピック, Hepburn: 1964-Nen Kaki Orinpikku), officially the Games of the XVIII Olympiad (Japanese: 第18回オリンピック競技大会, Hepburn: Dai Jūhachi-kai Orinpikku Kyōgi Taikai) and commonly known as Tokyo 1964 (Japanese: 東京1964), were an international multi-sport event held from 10 to 24 October 1964 in Tokyo, Japan. Tokyo had been awarded the organization of the 1940 Summer Olympics, but this honor was subsequently passed to Helsinki due to Japan's invasion of China, before ultimately being cancelled due to World War II. Tokyo was chosen as the host city during the 55th IOC Session in West Germany on 26 May 1959.

The 1964 Summer Games were the first Olympics held in Asia, and marked the first time South Africa was excluded due to the use of its apartheid system in sports. Until 1960, South Africa had fielded segregated teams, conforming to the country's racial classifications; for the 1964 Games the International Olympic Committee demanded a multi-racial delegation to be sent, and after South Africa refused, they were excluded from participating. The country was, however, allowed to compete at the 1964 Summer Paralympics, also held in Tokyo, its Paralympic Games debut.The 1964 Games were also the first to be telecast internationally without the need for tapes to be flown overseas, as they had been for the 1960 Olympics four years earlier. The games were telecast to the United States using Syncom 3, the first geostationary communication satellite, and from there to Europe using Relay 1. These were also the first Olympic Games to have color telecasts, albeit partially. Certain events such as the sumo wrestling and judo matches, sports popular in Japan, were tried out using Toshiba's new colour transmission system, but only for the domestic market. The entire 1964 Olympic Games was chronicled in the ground-breaking 1965 sports documentary film Tokyo Olympiad, directed by Kon Ichikawa.

The games were scheduled for mid-October to avoid the city's midsummer heat and humidity and the September typhoon season. The previous Olympics in Rome in 1960 started in late August and experienced hot weather. The following games in 1968 in Mexico City also began in October. The 1964 Olympics were also the last to use a traditional cinder track for the track events. Since 1968, a smooth, synthetic, all-weather track has been used. The United States won the most gold medals, while the Soviet Union won the most overall medals.

Tokyo hosted the 2020 Summer Olympics, making it the first city in Asia to host the Summer Olympic Games twice. Japan also hosted the Winter Olympics twice with the Sapporo 1972 and Nagano 1998 games.