section_path: Jonathan's Space Report
section_name: Jonathan's Space Report
paragraph_text: Jonathan's Space Report
  
  In his free time, McDowell conducts research into the history of spaceflight, and since 1989 has written and edited Jonathan's Space Report, a free internet newsletter documenting technical details on satellite launches. This information, obtained from original sources including declassified Department of Defense documents and Russian-language publications, can also be found on McDowell's web site.
  
  In 1994, McDowell published a history of the North American X-15 spaceplane, in which he suggested that 80 kilometres (50 mi) should be adopted as the boundary of space. In the mesosphere, 80 km is nearly equal to 50 mi, the altitude used by the United States to confer astronaut status on pilots, as in the X-15 program itself. It also differs from the internationally accepted Kármán line altitude of 100 km, used by the Fédération Aéronautique Internationale for the same purpose. In 2018, McDowell published a refereed journal paper in Acta Astronautica making detailed physical arguments for the 80 km value.