Reconnaissance satellite in the context of "National Reconnaissance Office"

The Space Race (Russian: космическая гонка, romanized: kosmicheskaya gonka, IPA: [kɐsˈmʲitɕɪskəjə ˈɡonkə]) was a 20th-century competition between the Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability. It had its origins in the ballistic missile-based nuclear arms race between the two nations following World War II and the onset of the Cold War. The technological advantage demonstrated by spaceflight achievement was seen as necessary for national security, particularly in regard to intercontinental ballistic missile and satellite reconnaissance capability, but also became part of the cultural symbolism and ideology of the time. The Space Race brought pioneering launches of artificial satellites, robotic landers to the Moon, Venus, and Mars, and human spaceflight in low Earth orbit and ultimately to the Moon.

Public interest in space travel originated in the 1951 publication of a Soviet youth magazine and was promptly picked up by US magazines. The competition began on July 29, 1955, when the United States announced its intent to launch artificial satellites for the International Geophysical Year. Five days later, the Soviet Union responded by declaring they would also launch a satellite "in the near future". The launching of satellites was enabled by developments in ballistic missile capabilities since the end of World War II. The competition gained Western public attention with the "Sputnik crisis", when the USSR achieved the first successful satellite launch, Sputnik 1, on October 4, 1957. It gained momentum when the USSR sent the first human, Yuri Gagarin, into space with the orbital flight of Vostok 1 on April 12, 1961. These were followed by a string of other firsts achieved by the Soviets over the next few years.

A space telescope (also known as space observatory) is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Space telescopes avoid several problems caused by the atmosphere, including the absorption or scattering of certain wavelengths of light, obstruction by clouds, and distortions due to atmospheric refraction such as twinkling. Space telescopes can also observe dim objects during the daytime, and they avoid light pollution which ground-based observatories encounter. They are divided into two types: Satellites which map the entire sky (astronomical survey), and satellites which focus on selected astronomical objects or parts of the sky and beyond. Space telescopes are distinct from Earth imaging satellites, which point toward Earth for satellite imaging, applied for weather analysis, espionage, and other types of information gathering.

Television InfraRed Observation Satellite (TIROS) is a series of early weather satellites launched by the United States, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth, enabling scientists to view the Earth from a new perspective: space. The program, promoted by Harry Wexler, proved the usefulness of satellite weather observation, at a time when military reconnaissance satellites were secretly in development or use. TIROS demonstrated at that time that "the key to genius is often simplicity". TIROS is an acronym of "Television InfraRed Observation Satellite" and is also the plural of "tiro" which means "a young soldier, a beginner".

The Advanced Research Projects Agency (now DARPA) initiated the TIROS program in 1958 and transferred the program to the National Aeronautics and Space Administration (NASA) in 1959. Participants in the TIROS program also included, United States Army Signal Research and Development Laboratory, Radio Corporation of America (RCA), the United States Weather Bureau Service, the United States Naval Photographic Interpretation Center (NPIC), the Environmental Science Services Administration (ESSA), and the National Oceanic and Atmospheric Administration (NOAA).

Space warfare is combat in which one or more belligerents are in outer space. The scope of space warfare includes ground-to-space warfare, such as attacking satellites from the Earth; space-to-space warfare, such as satellites attacking satellites; and space-to-ground warfare, such as satellites attacking Earth-based targets. The 1967 Outer Space Treaty forms the basis of space law; it prohibits permanent basing of weapons of mass destruction including nuclear weapons in space and the military use of celestial bodies, but does not prohibit the military use of Earth orbit or military space forces. Independent space forces are operated by the United States (US Space Force) and China (People's Liberation Army Aerospace Force). Russia operates significant space assets under the Russian Space Forces.

The Cold War prompted the start of the militarization of space. Military satellites have been launched since the late 1950s, for communications, navigation, reconnaissance and munitions guidance. The Gulf War is sometimes called the "first space war" for the US' use of these capabilities. The use of Starlink satellites by Ukraine has played a major role in the Russian-Ukrainian War.

Lacrosse or Onyx was a series of terrestrial radar imaging reconnaissance satellites operated by the United States National Reconnaissance Office (NRO). While not officially confirmed by the NRO or the Government of the United States prior to 2008, there was widespread evidence pointing to its existence, including one NASA website. In July 2008, the NRO itself declassified the existence of its synthetic aperture radar (SAR) satellite constellation.

According to former Director of Central Intelligence Admiral Stansfield Turner, Lacrosse had its origins in 1980 when a dispute between the Central Intelligence Agency and the U.S. Air Force as to whether a combined optical/radar reconnaissance satellite (the CIA proposal) or a radar-only one (the USAF proposal) should be developed was resolved in favor of the USAF.

SAR-Lupe is Germany's first reconnaissance satellite system and is used for military purposes. SAR is an abbreviation for synthetic-aperture radar, and "Lupe" is German for magnifying glass. The SAR-Lupe program consists of five identical (770 kg) satellites, developed by the German aeronautics company OHB-System, which are controlled by a ground station responsible for controlling the system and analysing the retrieved data. A large data archive of images will be kept in a former Cold War bunker belonging to the Kommando Strategische Aufklärung (Strategic Reconnaissance Command) of the Bundeswehr. The total price of the satellites was over 250 million Euro.