Ancient Greek astronomers believe the Earth is the centre of the Universe and that all celestial bodies orbit the Earth. Anaximander describes this in approximately 550 BCE.

Islamic astronomer Ibn al-Shatir of the Maragha school accepts the geocentric model but produces configurations that challenge the Ptolemaic model. His calculations are similar to the later calculations of Copernicus.

Polish astronomer Copernicus proposes that the Sun is stationary in the centre of the Universe and the Earth and other planets revolve around it. The church suppresses this controversial idea but it revolutionises astronomy.

German astronomer Johannes Kepler uses the term ‘satellite’ to describe the moons orbiting Jupiter. He develops the three laws of planetary motion, providing evidence for the Copernican heliocentric model.

Russian Konstantin Tsiolkovsky proposes using rocketry to launch spacecraft and calculates the orbital speed required for a minimal orbit around the Earth.

British science fiction writer and inventor Arthur C Clarke publishes an article showing how geostationary satellites could be used for worldwide radio and television broadcasts and communication.

The Soviet Union launches Sputnik, the first artificial satellite to orbit around the Earth, marking a significant milestone in space exploration.

Sputnik 1 was the first artificial satellite to be launched into space by the Soviet Union. It marked the beginning of the space age and the start of the space race between the Soviet Union and the United States.

On November 3, 1957, the USSR launched Sputnik 2, carrying a dog named Laika into space, making them the first nation to send a living organism into orbit.

On January 31, 1958, the US entered the space race by launching Explorer 1, the first US satellite to reach orbit, leading to the discovery of the Van Allen radiation belt.

Explorer 1 was the first satellite launched by the United States in response to the Soviet Union's Sputnik 1. It discovered the Van Allen radiation belts around Earth.

Vanguard-1 was the first spacecraft to have a solar-powered electric power source. It was a small aluminum sphere with antennas protruding out from it. It remained in orbit for about 240 years, making it the oldest human-made object still in orbit.

Explorer-3 was the second successful launch in the Explorer satellite series. It confirmed the presence of the Van Allen Belts and functioned for 93 days before decaying in orbit.

Sputnik-3 was a large research satellite made to explore the upper atmosphere and near space. It ended its mission after 692 days in orbit and burned up in the atmosphere on re-entry.

On December 18, 1958, the US launched SCORE, the world's first communications satellite, which broadcasted a Christmas message from US President Dwight D. Eisenhower, marking the first broadcast of a human voice from space.

On January 2, 1959, the USSR launched Luna 1, the first human-made object to leave Earth's orbit and orbit the sun instead of the Moon.

On August 2, 1959, the US launched Explorer 6, the world's first weather satellite, capturing the first images of Earth from space.

On September 12, 1959, the USSR launched Luna 2, becoming the first spacecraft to reach the surface of the Moon.

NASA launches Tiros-1, the first weather satellite considered a success, which begins the era of weather satellite technology.

Russian cosmonaut Yuri Gagarin becomes the first person to orbit the Earth in his Vostok spacecraft, a historic moment in human space exploration.

Telstar 1 was the first commercial satellite capable of transmitting live television, telephone, fax, and other signals across the Atlantic Ocean.

Syncom 3 satellite broadcasted the 1964 Olympic Games held in Tokyo across televisions in the US, showcasing the potential of satellite technology in telecommunication.

In 1965, the US satellite Mariner 4 successfully journeyed to Mars, capturing the first close-up images of the Martian surface.

The Applications Technology Satellite series was a set of six NASA spacecraft launched between December 7, 1966, and May 30, 1974. They were created to test new technologies for communications, meteorology, and navigation satellites.

China launches its first satellite Dongfanghong 1 into Earth orbit, becoming the fifth nation to achieve independent launch capability.

The Soviet Union launches the first space station Salyut 1, marking the beginning of human presence in space for extended periods.

The Synchronous Meteorological Satellite-1 (SMS-1) was launched in 1974, marking the beginning of cooperation between NASA and NOAA. It was the first operational satellite designed to sense meteorological conditions in geostationary orbit.

The first Geostationary Operational Environmental Satellite (GOES) was launched on October 16, 1975. These early satellites were spin stabilized and operated from 1975 to 1994, providing valuable earth observation data.

The first space shuttle Columbia is launched, initiating the American Space Shuttle programme that revolutionizes human spaceflight.

GOES-8, launched on April 13, 1994, was the first three-axis stabilized spacecraft in the GOES series. It marked a significant advancement in satellite technology for weather monitoring and earth observation.

The first component of the modular International Space Station is launched, beginning an era of international cooperation in space exploration.

On April 15, 1999, Landsat 7 was successfully launched from Vandenberg Air Force Base in California. The satellite's Enhanced Thematic Mapper Plus (ETM+) was designed for global change studies, land cover monitoring, and large area mapping.

An international research effort that obtained radar return information to create a high-resolution digital topographic database of Earth. The radar system flew on board the Space Shuttle Endeavour during the STS-99 mission in February 2000.

Crew members on the International Space Station started photographing the Earth in November 2000 to monitor changes over time caused by both human activities and natural events. The images captured are used for various purposes including tracking natural disasters and supporting relief efforts.

The European Space Agency launches the Rosetta to rendezvous with Comet 67P, showcasing advancements in satellite technology for deep space exploration.

On May 24, 2006, the GOES-13 satellite was launched, marking the beginning of the next generation of GOES satellites. It featured advanced technology for improved image navigation and registration, enhancing severe storm detection for the NOAA National Weather Service.

NASA launched the Lunar Crater Observation and Sensing Satellite (LCROSS) to confirm the presence or absence of ice on the moon.

As of March 7, 2014, there were over 6,000 satellites launched into orbit, showcasing the exponential growth in satellite technology since the launch of Sputnik in 1957.

CATS is a lidar remote sensing instrument launched in January 2015 to provide range-resolved profile measurements of atmospheric aerosols and clouds from the ISS.

DESIS, developed by DLR and Teledyne Brown Engineering, is mounted on the MUSES platform, providing benefits in agricultural management, disaster assessment, and environmental monitoring.

SAGE III-ISS provides crucial, long-term measurements of ozone concentrations, water vapor, aerosols, and trace gases from the International Space Station, helping humans understand and care for Earth's atmosphere.

A service that enables control and ingestion of data from satellites without having to purchase or build satellite ground station infrastructure.

OCO-3 is a space instrument developed by NASA to study the distribution of carbon dioxide on Earth, focusing on daily variations in carbon dioxide release and uptake by plants in major tropical rainforests.