The world's most expensive space project celebrates its 20th anniversary on Tuesday.

Viewed from a window inside the cupola, the International Space Station's
Viewed from a window inside the cupola, the International Space Station's "window to the world," is the Japanese Exploration Agency's H-II Transfer Vehicle-7. (NASA)

The International Space Station (ISS) was launched on 20 November 1998 from the Baikonur Cosmodrome in Kazakhstan in order to carry out space missions for the humanity.

The ISS platform includes several pressurised parts starting from 1998 to 2011, the year when the last part was fitted.

The fitting missions were launched by Russian Soyuz and Proton rockets and the US Space Shuttles.

The ISS is serving as a research laboratory where crew members can work on many scientific field from astronomy to physics.

Here are five things to know about the ISS;

1. Most occupied space station by humans

The ISS has been continuously occupied by humans since November 2000. Around 230 Astronauts from 18 nations have attended the space missions in the ISS. 

There are six sleeping quarters, one gym and two bathrooms in the ISS. Peggy Whitson holds the record of living the longest (665 days) in the space.

The Unity module offers the perfect space for an out of this world jam session with Expedition 55 crew members.
The Unity module offers the perfect space for an out of this world jam session with Expedition 55 crew members. (NASA)

2. Most expensive project

The ISS is the single most expensive space project worth $100 billion, with the cooperation of 16 countries. It is also the largest human made body in low Earth orbit.

NASA astronaut Ricky Arnold is pictured during a spacewalk he conducted with fellow NASA astronaut Drew Feustel (out of frame) on June 14, 2018.
NASA astronaut Ricky Arnold is pictured during a spacewalk he conducted with fellow NASA astronaut Drew Feustel (out of frame) on June 14, 2018. (NASA)

3. Landmark of cooperation after the Cold War

During the Cold War, the US and Russia were in the space race competing for greater influence. However, the ISS became a landmark collaboration between two countries after end of the Cold War.

Expedition 57 crew members Alexey Ovchinin of Roscosmos, left, and Nick Hague of NASA, right, review training documents with a Gagarin Cosmonaut Training Center instructor as they prepare for their upcoming launch.
Expedition 57 crew members Alexey Ovchinin of Roscosmos, left, and Nick Hague of NASA, right, review training documents with a Gagarin Cosmonaut Training Center instructor as they prepare for their upcoming launch. (NASA)

4. Third brightest object seen from the world

The ISS is the third brightest object, visible also with naked eye, in the night sky from Earth after moon and Venus. 

Nighttime View of the Strait of Gibraltar
Nighttime View of the Strait of Gibraltar (NASA)

5. High speed

The ISS can fly around the world in only 90 minutes, 16 times per day. It can quickly collect detailed data from the world.

Astronauts on the International Space Station captured a series of incredible star trail images on Oct. 3, 2016, as they orbited at 17,500 miles per hour. The station orbits the Earth every 90 minutes, and astronauts aboard see an average of 16 sunrises and sunsets every 24 hours.
Astronauts on the International Space Station captured a series of incredible star trail images on Oct. 3, 2016, as they orbited at 17,500 miles per hour. The station orbits the Earth every 90 minutes, and astronauts aboard see an average of 16 sunrises and sunsets every 24 hours. (NASA)
Source: TRT World