Microgravity in the context of "Centrifuge"

The International Space Station (ISS) is a large space station that was assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United States), Roscosmos (Russia), ESA (Europe), JAXA (Japan), and CSA (Canada). As the largest space station ever constructed, it primarily serves as a platform for conducting scientific experiments in microgravity and studying the space environment.

The station is divided into two main sections: the Russian Orbital Segment (ROS), developed by Roscosmos, and the US Orbital Segment (USOS), built by NASA, ESA, JAXA, and CSA. A striking feature of the ISS is the Integrated Truss Structure, which connect the station's vast system of solar panels and radiators to its pressurized modules. These modules support diverse functions, including scientific research, crew habitation, storage, spacecraft control, and airlock operations. The ISS has eight docking and berthing ports for visiting spacecraft. The station orbits the Earth at an average altitude of 400 kilometres (250 miles) and circles the Earth in roughly 93 minutes, completing 15.5 orbits per day.

Mir (Russian: Мир, IPA: [ˈmʲir]; lit. 'peace' or 'world') was a space station operated in low Earth orbit from 1986 to 2001, first by the Soviet Union and later by the Russian Federation. Mir was the first modular space station and was assembled in orbit from 1986 to 1996. It had a greater mass than any previous spacecraft. At the time it was the largest artificial satellite in orbit, succeeded by the International Space Station (ISS) after Mir's deorbiting. The station served as a microgravity research laboratory in which crews conducted experiments in biology, human biology, physics, astronomy, meteorology, and spacecraft systems with a goal of developing technologies required for permanent occupation of space.

Mir was the first continuously inhabited long-term research station in orbit and held the record for the longest continuous human presence in space at 3,644 days, until it was surpassed by the ISS on 23 October 2010. It holds the record for the longest single human spaceflight, with Valeri Polyakov spending 437 days and 18 hours on the station between 1994 and 1995. Mir was occupied for a total of twelve and a half years out of its fifteen-year lifespan, having the capacity to support a resident crew of three, or larger crews for short visits.

Animals in space originally served to test the survivability of spaceflight, before human spaceflights were attempted. Later, many species were flown to investigate various biological processes and the effects microgravity and space flight might have on them. Bioastronautics is an area of bioengineering research that spans the study and support of life in space. To date, seven national space programs have flown non-human animals into space: the United States, Soviet Union, France, Argentina, China, Japan and Iran.

A wide variety of non-human animals have been launched into space, including monkeys and apes, dogs, cats, tortoises, mice, rats, rabbits, fish, frogs, spiders, insects, and quail eggs (which hatched on Mir in 1990). The US launched the first Earthlings into space, with fruit flies surviving a 1947 flight, followed by primates in 1949. The Soviet space program launched multiple dogs into space, with the first sub-orbital flights in 1951, and first orbital flights in 1957.