Commercial cargo transport service for ISS

Abstract The United States space exploration goals expressed in January 2004 call for the retirement of the Space Transportation System (STS or Shuttle) following completion of International Space Station (ISS) construction. Since the Shuttle is instrumental in transporting large quantities of cargo to and from the ISS, this functional capability must be preserved to ensure ongoing station operations in a post-Shuttle era. Fulfilling ongoing cargo transport requirements to the ISS is a prime opportunity for NASA to reduce costs and preserve and repurpose the unique and limited Shuttle resource by acquiring cargo transportation services commercially. Further, implementing such a service prior to retirement of the Shuttle reduces risk to the vehicle and her crews by eliminating their use for routine cargo transport missions while accelerating the readiness for alternative ISS-support transportation. This paper examines ISS cargo traffic requirements, provides an assessment of current and proposed cargo vehicles envisioned for ISS cargo transport, and examines major cost drivers associated with development of cargo transport systems. Consideration of these factors, coupled with SPACEHAB's extensive involvement in cargo transport to the Mir and ISS, has led to the development of a Commercial Payload Service (CPS). The CPS mission models, system description and performance, and structure of the commercial service model are presented.