The International Space Station is approved to operate through 2024, and NASA likely will not build the next station. Instead, the agency will depend on the technology of outside companies like Sierra Space of Colorado and Houston-based Axiom Space. The space station has continuously housed a rotation of astronauts from 19 countries since 2000. The station first launched segments in 1998, and it has the only laboratory for long-duration microgravity research. It has also been instrumental in creating more efficient water filtration systems and exploring new ways to treat Alzheimer’s and cancer diseases.