Living Among the Stars: Space Station Life Quiz

While it looks like there is no gravity, the ISS is in "free fall" around Earth. This state is called microgravity. The Earth's gravity is still about 90% as strong, but because the station moves so fast sideways, it falls around the curve of the planet, making objects float.

True. Because the ISS orbits the Earth once every 90 minutes at 17,500 miles per hour, the crew sees a sunrise or sunset every 45 minutes. They use Coordinated Universal Time (UTC) to maintain a consistent 24-hour schedule.

On Earth, warm air rises due to convection. In space, warm air stays in a bubble around an astronaut's face. Without fans to circulate the air, an astronaut could breathe in too much of their own exhaled carbon dioxide while sleeping.

Food must be prepared to prevent floating debris. Salt and pepper are liquids because grains would float away. Crumbs are dangerous because they can be inhaled or clog filters. Most food is freeze-dried and requires water to be eaten.

To prevent floating into sensitive instruments, astronauts sleep in small stations about the size of a phone booth. They zip themselves into sleeping bags tethered to the wall, which provides security and keeps them in place for their 8-hour rest.

True. In microgravity, the body doesn't work against gravity to move. Without intense daily exercise using specialized machines like the ARED, astronauts would lose significant bone density and muscle mass, making it dangerous to return to Earth's gravity.

In space, the inner ear cannot tell which way is down. To stay organized, the ISS uses labels on walls and lights on "ceilings." However, astronauts can work in any orientation, often standing on the ceiling to perform tasks.

Because it is expensive to launch heavy water, the ISS uses a Water Recovery System. It filters moisture from the air and waste. This is a vital "closed-loop" system required for long-term space exploration and survival.

There are no showers because water would float away in blobs. Astronauts use soapy wet towels and no-rinse shampoo. Since they can't spit into a sink, they usually swallow their toothpaste or spit it into a tissue.

NASA and partners send cargo ships (like SpaceX Dragon) every few months. These carry fresh food, experiments, parts, and personal items. These "care packages" are essential for the physical and mental health of the crew.

True. Including the solar arrays, the station spans about 357 feet. The living space (pressurized modules) is roughly the size of a large six-bedroom house. This scale allows international scientists to live and work together.

In microgravity, fluids shift toward the head (puffy face syndrome). This can put pressure on the back of the eyes, causing vision changes. Monitoring this is a major part of space medicine to prepare for missions to Mars.

The ISS is a laboratory where astronauts conduct research on fire, plant growth, and human aging in microgravity. This data is sent back to Earth to solve problems in medicine, engineering, and environmental science.

Mental health is a priority. Astronauts enjoy the Cupola, a seven-window module with a view of Earth. They also have internet for emails, video calls, and may bring small instruments to play in microgravity.

An airlock is a chamber with two airtight doors. It allows astronauts to put on spacesuits and transition to the vacuum of space for repairs (EVAs) without losing the station's internal air pressure.

False. While the vacuum outside is silent, the inside is filled with air. It is quite noisy due to the constant hum of fans, pumps, and life-support systems. Astronauts often wear earplugs to sleep.

Because fluids move to the head, astronauts often feel congested. Since smell and taste are linked, food tastes bland. This is why many astronauts prefer very spicy foods and hot sauce to make meals more flavorful.

Without gravity, astronauts would float off the treadmill. They wear a harness connected to bungee cords that pull them toward the machine, simulating body weight so they can perform the cardio needed for heart and bone health.

Trash is packed into uncrewed cargo ships that burn up in Earth's atmosphere upon reentry. Scientific waste or broken equipment to be analyzed is returned in capsules like the SpaceX Dragon for engineers to study.

The space toilet uses air-flow suction to pull waste away from the body since gravity won't. Liquid waste is recycled into drinking water, while solid waste is compacted and stored for disposal in cargo ships.