 He could not make a corrective teleport into the space station - he could not open a portal back to the planet.He could only remain in orbit as that orbit decayed and he ended up burning up in the atmosphere upon re-entry, along with the book.With the death of Kostya and others in the recent past, the Day Watch in Moscow is down to one Higher Level Magician (Zavulon) while The Night watch in Moscow has four (Gesar/Olga/Sveta/Anton).