Abstract: : The purpose of this project was to expand and enhance IDA's capabilities to estimate the future acquisition costs and schedules of space systems This study accumulated information on launch systems, manned space systems, and interplanetary systems from NASA Cost and schedule information was collected on representative programs, estimating methods, and supporting databases The results of the effort include this document, which summarizes costs and schedules of representative space systems along with cost-estimating methods currently being applied, and also a library of over 500 documents that describe technical, schedule, and cost characteristics of US space activities during the past 40 years Preliminary findings of this study have been applied to estimate the costs of manned access to space