Hypersonic missile startup Castelion raises $1 billion

Space Explainer: The ISS & Life in Orbit

The International Space Station has been continuously staffed since November 2000, making it the longest-running human outpost off Earth. It orbits roughly 400km up, circling the planet every 90 minutes at about 28,000 km/h — meaning the crew sees a sunrise or sunset every 45 minutes.

Crew members typically rotate every 5-6 months, arriving and departing on Soyuz or Crew Dragon spacecraft. Their days are tightly scheduled around scientific experiments in microgravity, station maintenance, and roughly 2.5 hours of mandatory daily exercise to counteract the bone and muscle loss that comes from living without gravity.