MCQ Detailed View

The International Space Station (ISS) is a large human-made satellite that orbits Earth at an average altitude of around 400 kilometers (about 250 miles) above the surface. It is the largest artificial object in space and serves as a research laboratory where astronauts conduct experiments in microgravity.

The ISS travels at a speed of approximately 28,000 kilometers per hour (17,500 mph). Because of this high speed, it completes one full orbit around Earth roughly every 90 minutes. This means that astronauts aboard the ISS see about 16 sunrises and 16 sunsets every 24 hours, as the station keeps circling the planet multiple times a day.

Its orbital altitude is carefully maintained to balance the pull of Earth's gravity and the forward speed of the station. At around 400 km, the ISS is high enough to avoid most of the atmospheric drag but close enough for regular supply missions from Earth.

The other options in the question are not correct:

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  60 minutes is too short for a complete orbit at the station’s speed and altitude.

  
  


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  500 km altitude is higher than the ISS usually operates; its normal range is 370–420 km, as higher altitudes would make resupply missions more challenging.

  
  

The correct answer is 90 minutes at an altitude of about 400 km, which reflects the real orbital path of the ISS. This fast orbit allows the station to pass over most parts of Earth regularly, making it visible from many locations during its path.

This MCQ belongs to Everyday Science (General Science) because it explains real-world space science and orbital mechanics, helping students understand how satellites and spacecraft move around Earth.