On Nov. 2, 2000, an American astronaut and two Russian cosmonauts became the first humans to take up residence on the International Space Station. Since then, the ISS has hosted more than 220 people (including seven Canadians) from more than a dozen countries. Here are 15 facts from NASA and the Canadian Space Agency about the space station and what life is like on board:
It's as long as a football field
The International Space Station is about the length of a Canadian football field (100 metres) and has as much living space inside as a five-bedroom house. The station weighs about 420,000 kilograms.
Someone's always home
Since that first crew arrived 15 years ago, there has always been someone living on the space station. Crews of three to six people are on board at all times. Expeditions to the ISS usually last about six months.
The food's not so bad...
According to NASA, food favourites aboard the station include shrimp cocktail, tortillas and macaroni and cheese. It takes about 6,350 kilograms of supplies to feed three people for six months. Since the first expedition, space station residents have eaten more than 26,500 meals.
But no bread allowed
Food that produces crumbs, like bread, isn't a good choice in weightless space because loose crumbs can float and contaminate the environment inside the space station.
They have to recycle water
Delivering fresh water into space is extremely expensive, so the space station's water recovery system reduces the water resupply needs from about four litres a day to about 1.3 litres. The goal is to reuse as much water as possible, including wastewater from washing, human urine and sweat. The Environmental Control and Life Support System on board the station includes a urine processor. Since it was activated in 2008, NASA says, more than 10,000 kilograms of drinkable water has been generated from crew members' urine.
Speaking of urine...
The space station bathroom facilities use suction instead of water to flush. People urinate into a hose that takes the urine to the processor that turns it into water. When it comes to excrement, there is a sort of toilet that people squat over, depositing their business into a bag. Because it's a microgravity environment, they use straps to keep from floating away.
Partly to conserve water and partly because water clings to the body in a microgravity environment, astronauts take sponge baths rather than showers. They use no-rinse shampoo and a towel to wash their hair. They have to be careful to contain any loose hairs that wind up on the towel, because if hairs float away, they become a safety hazard. Astronauts could inhale them and hair can clog air filters.
In addition to conducting research and maintaining the space station, crew members work out about two hours each day to keep their bones and muscles strong. Because of the microgravity, lifting traditional weights would have no effect. Instead, astronauts use resistance bands. For cardiovascular activity, there's a modified exercise bicycle and treadmill.
Astronauts need weekends, too
Space station crew members work five days a week and get two days off to relax. Every weekend, the astronauts can have private video-conferences with their families back on Earth. There's internet connectivity, so they can also keep in touch with family and friends through email and internet phone, or surf the web. During downtime, astronauts can also watch TV and movies on their laptops, or simply gaze out the window at the stunning view.
Forget something? Print it.
The ISS has a 3-D printer on board that has been used to make 20 objects, including a ratchet wrench.
Travelling at 28,000 kilometres an hour, the International Space Station makes a full trip around the world about once every 90 minutes. The crew is in daylight half the time and in darkness the other half. That means astronauts have 16 sunrises and 16 sunsets they can watch every single day.
Then how do they know when it's bedtime?
Each 24-hour period has 8.5 hours allocated for sleeping, and astronauts try to stay on the same schedule, using Greenwich Mean Time to stay consistent, according to the Canadian Space Agency.
Sleeping strapped to the wall
The space station has small personal compartments, or sleep pods, with sleeping bags fastened to the wall inside so they stay in place in the weightless environment. In a video produced by the Canadian Space Agency and NASA, astronaut Chris Hadfield describes the experience.
"You might think it's uncomfortable not having a mattress and a pillow," Hadfield says. "But without gravity of course, you don't need anything to hold you up. You can just completely relax... You don't even have to hold your head up."
We can see the station from Earth
Orbiting about 370 kilometres above the Earth, the space station is visible for anywhere from seconds to minutes on specific days and times, depending where you are in the world. NASA offers a "Spot the Station" lookup service to find out when the next sightings are.
A 'springboard' to Mars
The International Space Station is the "springboard to NASA's next great leap in exploration," according to the agency's website. Astronauts on board the station conduct research about living and working in space that isn't possible to do on Earth. NASA says the lessons from the space station will help pave the way toward the goal of sending people further into the solar system, including Mars.