NASA will say goodbye to the International Space Station in 2030 − and welcome in the age of commercial space stations
- Written by John M. Horack, Professor of Mechanical and Aerospace Engineering, The Ohio State University

For 24 hours a day, seven days a week since November 2000, NASA and its international partners have sustained a continuous human presence in low-Earth orbit, including at least one American – a streak that will soon reach 25 years.
When viewed in the history of...