CHAPTER 1 The Evolution of the Space Shuttle Program
CHAPTER 1 The Evolution of the Space Shuttle Program
―第1章 スペースシャトルプログラムの進化―
More than two decades after its first flight, the Space Shuttle remains the only reusable spacecraft in the world capable of simultaneously putting multiple-person crews and heavy cargo into orbit, of deploying, servicing, and retrieving satellites, and of returning the products of on-orbit research to Earth. These capabilities are an important asset for the United States and its international partners in space. Current plans call for the Space Shuttle to play a central role in the U.S. human space flight program for years to come.

The Space Shuttle Programs remarkable successes, how-ever, come with high costs and tremendous risks. The Feb-ruary 1 disintegration of Columbia during re-entry, 17 years after Challenger was destroyed on ascent, is the most recent reminder that sending people into orbit and returning them safely to Earth remains a difficult and perilous endeavor.

It is the view of the Columbia Accident Investigation Board that the Columbia accident is not a random event, but rather a product of the Space Shuttle Programs history and current management processes. Fully understanding how it hap-pened requires an exploration of that history and manage-ment. This chapter charts how the Shuttle emerged from a series of political compromises that produced unreasonable expectations ュ even myths ュ about its performance, how the Challenger accident shattered those myths several years af-ter NASA began acting upon them as fact, and how, in retro-spect, the Shuttles technically ambitious design resulted in an inherently vulnerable vehicle, the safe operation of which exceeded NASAs organizational capabilities as they existed at the time of the Columbia accident. The Boards investigation of what caused the Columbia accident thus begins in the fields of East Texas but reaches more than 30 years into the past, to a series of economically and politically driven decisions that cast the Shuttle program in a role that its nascent technology could not support. To understand the cause of the Columbia accident is to understand how a program promising reliability and cost efficiency resulted instead in a developmental vehicle that never achieved the fully operational status NASA and the nation accorded it.