Today marks the 16th anniversary of the first space shuttle flight to assemble the International Space Station. Let’s celebrate 16 years of the ISS with 15 things you may not have known about the world’s shared space station. 

1. Sixteen nations were involved in the construction of the ISS: The United States, Russia, Canada, Japan, Belgium, Brazil, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom.  

2. Sixty-five miles per hour may be a pretty standard speed limit on highways here on Earth, but up in orbit, the ISS travels a whopping 5 miles-per-second. That means the station circles the entire planet once every 90 minutes.  

3. You may think your house or apartment is spacious, but it’s got nothing on the ISS. At about 357.6 feet (or 109 meters) long, the International Space Station gives astronauts plenty of room to stretch out.  

4. Made up of hundreds of major and minor components, the ISS is the largest manned object ever put into space. The ISS has a pressurized volume of 32,333 cubic feet, the same as a Boeing 747. It's four times larger than the Russian space station MIR and five times larger than the U.S. station Skylab. 

5. The ISS is the single most expensive object ever built. The cost of the ISS has been estimated at over $120 billion.

6.  There are only two bathrooms on the entire station. The urine of both the crewmembers and laboratory animals is filtered back into the station’s drinking water supply, so at least the astronauts will never get thirsty. 

7. Just because you’re in space doesn’t mean you can’t get a virus on your computer. The 52 computers onboard the ISS have been infected by viruses more than once. The first was a worm known as the W32.Gammima.AG, which started spreading by stealing passwords to online video games on Earth. It wasn’t a big deal, though—NASA responded by calling the virus a “nuisance.” 

8. The ISS is a veritable hub of space traffic. In June of 2014, four separate international spacecraft were docked there, including the Progress M-21M cargo spacecraft, which departed the station on June 9 after a six-month mission to drop off food, fuel, and supplies. In September, a resupply mission from SpaceX visited the station, and an entire new crew arrived that month as well. The station’s full flight schedule has docking events planned through the summer of 2016.

9. The ISS is probably one of the only places you can actually smell space. A former ISS astronaut has described how a “metallic-ionization-type smell” occurs in the area where the pressure between the station and other docking crafts is equalized.   

10. Currently, the ISS is the third brightest object in the night sky after the moon and Venus. Eagle-eyed stargazers can even spot it if they look closely enough—it looks like a fast-moving airplane. If you can’t find it, NASA has a service called Spot the Station that texts you when and where it will pass over your location. If you want the opposite view (though we’re pretty sure you won’t be able to spot yourself), there is a live video feed pointing towards Earth that runs when the crew is off-duty.

11. Though the plan is to de-orbit the ISS in 2024, the oldest module of the station—the Russian-built and American-financed component called “Zarya,” first launched in 1998—can function until 2028 (as will The Unity, the first entirely American ISS component, which was also launched that year). Once the ISS kicks the bucket, the Russians plan to add their leftover modules to their new station, OPSEK (or Orbital Piloted Assembly and Experiment Complex). 

12. Because the human body tends to lose muscle and bone mass in zero gravity environments, all astronauts aboard the ISS must work out at least two hours a day to maintain normal Earth-based bodily health.  

13. The electrical systems on the ISS include 8 miles of wire. That’s longer than the entire perimeter of New York City's Central Park.

14. Astronauts eat three square meals a day on the ISS, but when they sit down for a meal, they don’t sit down at all. There are no chairs around the main eating area. Instead, the astronauts simply stabilize themselves and float. Diners have to be very slow and careful when bringing food to their mouths so it doesn't accidentally float across the station. Also, they can’t just stroll over to the refrigerator and grab a snack—all the food is canned, dehydrated, or packaged so it doesn’t require refrigeration.  

15.  Oxygen in the ISS comes from a process called “electrolysis,” which involves using an electrical current generated from the station’s solar panels to split water molecules into hydrogen and oxygen gas.