... This edition of the HST Data Handbook is organized as two volumes: Volume I provides general information on retreiving and reducing HST data and includes the more specific information needed to analyze data from the instruments currently onboard the spacecraft (FOC, FGS, NICMOS, STIS, and WFPC2). ... Part 1 of Volume 1 leads observers through the following three-step process, applicable to HST data files from any instrument: . ... These parts are described in the Volume I Preface. ...