CHAPTER 1
 INTRODUCTION

 A composite material is made of two or more constituent materials to form a new

material that is often superior in some respects to the constituents themselves. Composite

materials offer many advantages, such as lightweight, high specific stiffness and specific

strength, and low coefficient of thermal expansion. The next generation of reusable

space launch vehicles is supposed to provide a 10-fold reduction in the cost of launching

payloads into space, from $10,000 to $1,000 per pound in Figure 1-1.







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Figure 1-1. The X-33 test vehicle which NASA proposed as the replacement for the
 Space Shuttle.

 Reducing the structure weight of the vehicle is of paramount importance in

reducing the launch cost. Composite materials such as graphite/epoxy offer many

advantages such as low density, high specific stiffness and specific strength, and low