CHAPTER 1
 DEPLOYABLE STRUCTURES

 1.1 Introduction

 Deployable structures are structures capable of large configuration changes. Most

common is that the configuration changes from a packaged, compact state to a deployed,

large state. These structures are usually used for easy storage and transportation. They

are deployed into their service configuration when required. A well known example is

the umbrella. Deployable structures are sometimes known under other names such as

expandable, extendible, developable, and unfurlable structures.

 Deployable structures are both man-made and found in nature. Examples of

naturally found deployable structures are tubeworms such as Sebella, sea anemones such

as Metridium as well as leaves and flowers that deploy and fold on a daily basis.

Man-made deployable structures have many potential applications both on earth and in

space. In civil engineering, temporary or emergency structures have been used for a long

time. A more recent application is the retractable roof of large sports stadiums. In space,

deployable structures have been used since the former Soviet Union launched its first

satellite, Sputnik, on October 4, 1957. Deployable structures have a wide variety of

applications in space, because of their relative ease of storage, in booms, aerials and

masts as well as in deployable solar arrays.

 The requirements that have to be met by deployable structures in their operational

configuration (e.g., providing shelter from rain, in the case of umbrella, or forming an

accurate reflective surface, in the case of deployable reflector antenna for