Frederick D. Seward has been leader of the High Altitude Physics Group at the Lawrence Livermore Laboratory, Director of the Einstein Guest Observer Program at the Harvard-Smithsonian Center for Astrophysics, Head of Chandra User Support and an Assistant Director of the Chandra Observatory before retiring in 2004.
Philip A. Charles is Director of the South African Astronomical Observatory, which operates SALT, the largest telescope in the southern hemisphere. He has recently been head of the astronomy group at the University of Southampton's School of Physics and Astronomy.