Preface -- Introduction -- The Invisible Sky -- The History of X-Ray Astronomy -- X-Rays from the Sun?- A Fortuitous Discovery -- Filling up the Sky -- The Moon as Observing Assistant -- Rotating Blinders -- With Uhuru Toward New Frontiers -- Cygnus Cycles -- Magnetic Remote Sensing -- Einstein and EXOSAT -- ROSAT Ödash Creating a Satellite -- A New Type of Detector -- A Key Experience -- Pulsars Ödash Energy Beacons in the Universe -- The HEXE Balloon Program -- The Search for the Black Hole -- Contacts with Moscow -- ROSAT Ödash The ROentgen SATellite Project -- Grazing Reflections -- Technical Preparations -- Difficult Production -- How to Glue Glass to Metal?- ROSAT Goes International -- Imaging of X-Rays -- An Artificial "Optic Nerve -- Building a Satellite -- Commands from Bavari -- Early Morning Shock -- The Most Accurate X-Ray Map -- Astro-Navigation for ROSAT -- X-Ray Astronomy in Our Galaxy -- X-Rays from a Comet -- X-Rays from the Moon -- The Demystification of the Sky -- The Sun as a Prototypical Star -- What Heats the Corona? -- The Hertzsprung-Russell Diagram -- Helpful Mass Screenings -- Magnetic Fields Determine -- X-Ray Luminosity -- ROSAT Registers Strongest X-Ray Burst -- X-Ray Views into Cosmic Delivery Rooms -- X-Rays from the Sirius System -- The End of a Solar-Type Star -- Consequences of Proximity -- The Source of the X-Rays -- Magnetic White Dwarfs -- A Mysterious Gap -- Exploding Stars -- Supernova 1987 A -- ROSAT's First Measurements -- The Fast Supernova 1993 -- Galactic Supernovae -- A Stellar Explosion in the Stone Age -- Supersonic Stellar Debris -- Pulsars in X-Rays -- Revealing Cooling -- Enigma Geminga -- Classical X-Ray Binaries -- Difficult Search -- Black Holes -- The Particle Slingshot SS 433 -- Impenetrable Clouds -- A Hot Neighborhood -- Bubbles in the Milky Way -- The Galactic Center -- Perhaps a Black Hole?- X-Ray Astronomy Outside Our Galaxy -- Our Nearest Neighbors -- Fusion Processes on the Surface -- A New X-Ray Pulsar -- Super-Bubbles in the LMC -- The 30 Doradus Complex -- The Andromeda Galaxy -- Starburst Galaxies -- Active Galaxies -- An End to the Confusing Variety -- Multispectral Cooperation -- Gigantic Energy Beacons -- Clusters of Galaxies -- A Deep View Through the Lockman Hole -- Epilogue -- List of Acronyms -- Index.