Dr. Jonathan McDowell is an astrophysicist at the Smithsonian Astrophysical Observatory, part of the Harvard-Smithsonian Center for Astrophysics in Cambridge. A staff member of the Chandra X-ray Center, he studies black holes, quasars and X-ray sources in galaxies, as well as developing data analysis software for the X-ray astronomy community. Dr. McDowell has a B.A. in Mathematics and a Ph.D. in Astrophysics from the University of Cambridge, UK, and has previously worked at the Royal Greenwich Observatory, the Jodrell Bank Radio Observatory and NASA's Marshall Space Flight Center. He is also the editor of Jonathan's Space Report, a free internet newsletter founded in 1989 which provides technical details of satellite launches, and was formerly a columnist in Sky and Telescope Magazine. Dr. McDowell's web site, planet4589.org, provides the most comprehensive historical list of satellite launch information starting with Sputnik. He carries out research on space history topics using sources including declassified documents from the Department of Defense and Russian-language publications.