Accessno single word better describes the primary concern of the exploration and development of space. Every participant in space activitiescivil, military, scientific, or commercialneeds affordable, reliable, frequent, and flexible access to space. To Reach the High Frontier details the histories of the various space access vehicles developed in the United States since the birth of the space age in 1957. Each case study has been written by a specialist knowledgeable about the vehicle described and places each system in the larger context of the history of spaceflight. The technical challenge of reaching space with chemical rockets, the high costs associated with space launch, the long lead times necessary for scheduling flights, and the poor reliability of the rockets themselves show launch vehicles to be the space program's most difficult challenge.