At Home in the Sky

The bedrooms are the size of a telephone booth, there’s no running water, and the nearest bus station is 250 miles away. This doesn’t sound like a very attractive place to live, but a room here is highly coveted: Many people dream of living on the International Space Station. It’s like no place on Earth. On board you can float around freely without gravity and see astonishing views of the planet.

In 1998, the first part of the International Space Station, or ISS, was put in orbit around Earth. Over the years, many more pieces called modules were added. Since then, 103 people have called it home for an average of six months at a time and 224 more have visited for shorter stays. Up to six astronauts can live and work aboard the ISS at any time.

The ISS orbits Earth at an altitude of roughly 250 miles. Covering about the same area as a football field, the ISS is the largest human-made structure in space.

“It’s a spacecraft, a home, and a laboratory all at once,” says retired NASA astronaut David Wolf, who helped build the ISS. 

Science is the main purpose of the ISS. Space agencies from the U.S., Russia, Europe, Japan, and Canada all have laboratories aboard. But other countries and commercial firms can send up their research too. As of 2015, more than 1,700 experiments had been conducted on the ISS!

The space station is in such high demand because it offers an environment unlike any on Earth: microgravity, in which objects appear to be weightless. Many substances behave differently in microgravity. Fire is one example. A candle flame burns in a bluish sphere instead of the familiar red-orange cone we see on Earth. 

Researchers on the ISS have also had to come up with innovative solutions to deal with the challenges of space travel and living in cramped quarters. Some technologies we use today, like water-purification systems and a surgical robotic arm, were inspired by work done on the ISS.

The astronauts themselves are an experiment too. NASA hopes to send people to Mars by 2030. But before that, we need to know how outer space will affect human bodies in the long run. We already know that muscles and bones get weaker in the absence of gravity—that’s why astronauts have to run on the treadmill, ride a stationary bike, or lift weights for at least two hours every day. Long periods in space can also cause vision problems, make the heart smaller, and lower the immune system’s ability to fight off diseases. There’s also the psychological impact of being confined in a small space so far from home.

One surprising effect of living in space: Your sense of taste is dulled. That’s because microgravity affects the way fluids move in your body. “You feel like you have a mild cold all the time, so things don’t smell or taste as good,” says Wolf. 

Use this information to find the approximate volume of select living and work spaces on board the ISS. Round your answers to the nearest hundredth.

Destiny is the U.S. lab where astronauts conduct experiments. There’s also a stationary bike that they can use to keep fit. Destiny has a height of 8.5 meters and a radius of 2.15 m. What is its volume?

Zvezda is known as the heart of the ISS. It’s where the crew gathers in emergencies. Sleeping quarters, bathroom facilities, and exercise equipment are here. Most importantly for hungry astronauts, it’s where the pantry is! Zvezda has a height of 13.1 m and a radius of 2.1 m. What is its volume?  

Tranquility is where one of two toilets is located. The viewing Cupola is here too. Tranquility has a height of 6.7 m and a radius of 2.15 m. What is its volume? 

Kibo is the Japanese lab, whose name means “hope” in Japanese. It’s actually made up of two smaller modules. Module 1 has a height of 4.2 m and a radius of 2.2 m. Module 2 has a height of 11.2 m and a radius of 2.2 m. What is the volume of each module?

In April, the BEAM (Bigelow Expandable Activity Module) was attached to Tranquility, where it will remain for the next two years. The BEAM is an inflatable space habitat that’s being tested as a potential shelter for future missions. When expanded, the BEAM occupies 35.7 cubic meters and has a height of 4.01 m. What is its radius?

Columbus is the laboratory built by the European Space Agency. Here, astronauts grew red romaine lettuce in 2015—the first space-grown food they were allowed to eat! Columbus has a volume of 109.68 cubic meters and a radius of 2.25 m. What is its height?

Rank the modules in order from greatest volume to least volume: