 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 km should be adopted as the boundary of space.