The International Space Station (ISS) is an international cooperative project involving NASA (USA), ESA (Europe), CSA (Canada), JAXA (Japan), and Roscosmos (Russia). Over the years, these space agencies assembled the largest space station in history and the most extensive construction ever put into space.

Here are some cool International Space Station facts.

The International Space Station flies above us at around 248 miles (400 kilometers). That is within the low Earth orbit (LEO), where artificial satellites and space telescopes (such as the Hubble Space Telescope) can also be found.

But there isn’t a single ISS location because the station is orbiting Earth at an average speed of 17,300 mph (28,000 kph). That velocity is pretty common for objects in the low Earth orbit. In the case of the International Space Station, such a speed allows it to make a complete orbit around the world in around 90 minutes, 16 times per day.

And by “day” we refer to a 24-hour period. There is no day and night when traveling through that many time zones that quickly. In fact, astronauts at the International Space Station can see 16 sunrises and sunsets each “day”.

The exact International Space Station's location at a given time can be tracked through NASA’s ISS live stream.

The International Space Station is about 357 feet (109 meters) long and 240 feet (73 meters) wide —pretty much the size of a standard soccer field.

But it wasn't always like this. The International Space Station is made up of 16 pressurized modules that were assembled at different times.

The first module, Zarya, was launched in 1998 and measured 41 feet (about 12 meters) in length. The connecting module Unity, the first module of the ISS built by the US, was assembled a few days later. Unity is 18 feet (5.5 meters) long, so by the end of 1998, the ISS measured only 59 feet (17 meters) in length.

The ISS became bigger and bigger as new modules were attached to it, such as living quarters and laboratories belonging to different countries.

3. The ISS was created mainly for scientific purposes

The International Space Station derives from a NASA project called Freedom.

Freedom was a space station conceived in the 80s after the Apollo crewed Moon landing program ended, mainly due to budget constraints. By that time, humanity had already stepped on the moon in six different opportunities (Apollo 11 and Apollo 12 in 1969, Apollo 14 and Apollo 15 in 1971, Apollo 16 and Apollo 17 in 1972), so space agencies turned to the development of a crewed space station on which to conduct research, from which to make celestial and Earth observations, as a transportation and servicing node for space vehicles and satellites, and to serve as a staging base for deep-space exploration, including for the exploration of Mars and the prospect of a crewed mission to Mars.

In that sense, a permanently crewed space station could serve as a “test spacecraft” to evaluate the possibility of carrying out long-term operations in space (as in the case of a trip to Mars, which would take around nine months each way).

In fact, astronauts often conduct scientific research on astronomy, astrobiology, physics, space weather, space medicine, and other fields at the International Space Station’s microgravity laboratories.

The multi-purpose, multi-disciplinary laboratories at the International Space Station are:

• ISS National Lab (United States of America)
• Columbus (Europe)
• Japanese Experiment Module (JEM), also known as “Kibo” (Japan)

Astronauts at the International Space Station are believed to have conducted around 3,000 scientific experiments by 2020. Some of the most famous experiments performed at the International Space Station are:

• The particle physics experiment called “Alpha Magnetic Spectrometer” detected antimatter in cosmic rays (antiprotons and positrons).
• Investigations about the effects of long-term space exposure on the human body, such as “the Twins Study”, an experiment on twin astronauts Scott and Mark Kelly. Scott Kelly spent almost one year in space while his twin brother Mark stayed on Earth. NASA compared all physiological, molecular, and cognitive changes in the twins after that period, and found out that Scott Kelly had experienced changes in his microbiome (bacteria in the gut), damage in his DNA (possibly due to radiation), carotid artery wall thickening, the elevation of a protein that regulates water reabsorption, fluid shifts, and slowed aging.
• Earth-viewing remote sensing experiments, such as the Orbiting Carbon Observatory 3, which measures the amount of carbon dioxide in Earth’s atmosphere from above.

4. The question that ISS astronauts get asked the most is how do they go to the bathroom

And here’s the answer: the International Space Station has two bathrooms equipped with space toilets, which are specially designed to work in zero-gravity conditions.

Basically, when you lift the lid of a space toilet, you activate an airflow that keeps solid and liquid waste from flying off. Instead, the airflow pulls the waste away from the user’s body and into different receptacles.

The urine is particularly useful for ISS astronauts because it is recycled using the station’s water recovery system, a machine that filters and disinfects it so that it can become drinkable water.

It may sound gross, but urine is 95 percent water. Without the water recycling system (which also recycles sweat and grey water), space agencies would have to send about 5,000 gallons (18,000 liters) of water to the ISS annually to ensure a four-person crew's survival.

There are no alternative uses for solid waste, so solid waste is vacuumed into a canister, collected in airtight containers, and sent into Earth’s atmosphere to burn up.

5. The ISS will be deorbited in 2031

Sadly, this spectacular piece of engineering will likely be decommissioned in 2031 due to structural issues related to its age. For example, there have been several air leaks in the crew’s living quarters in recent years.

NASA expects private companies —such as Blue Origin— to launch their orbital laboratories and/or space platforms before that time. According to NASA’s transition plan, these commercial low-Earth orbit stations will replace the ISS in the near future.

Roscosmos, the Russian space agency involved in the ISS creation, has already announced that it will leave the ISS in 2024 to build its station.

The ISS is expected to be vacated in 2030 and deorbited in early 2031, with any remnants directed to land around Point Nemo, the Earth's farthest point from land.