Book excerpt: This book provides a record of support provided to Japan by the international community during the 2011 Great East Japan Earthquake, using the disaster as an example of international collaboration in the field of space-based disaster response. At the time of the 2011 Great East Japan Earthquake, 27 satellites from 14 countries and regions repeatedly and collaboratively observed the disaster area from space to support disaster response activities by observing the situation in real time. This book is a record of that activity. Through the response to the earthquake and subsequent tsunami, it was empirically proven that space-based responses with international collaboration can effectively support relief efforts during mass catastrophes.