Introduction to the Special Section on Healthcare for Space, Space for Healthcare.

The International Space Station (ISS) has been critical in increasing our understanding of space exploration and healthcare during the last two decades. As the only long-lasting microgravity laboratory in space, the ISS has provided a unique environment for researchers to conduct experiments that would be impossible on Earth. These discoveries have aided astronauts in staying healthy in space and have resulted in new treatments and therapies for humans on Earth. With more services dependent on space assets and the public's inclusion in commercial human spaceflight, new prospects in healthcare are emerging, and space is becoming the next frontier in our quest for improved health.