Atlas V Secondary Payload Carrier Systems - development approach, issues, and solutions

Lockheed Martin Space Systems Company has developed an innovative approach to providing small, secondary payload class spacecraft access to space. This alternate approach to the traditional use of dedicated small launch vehicles is based on offering flight for up to five secondary payloads on Atlas V missions with excess capacity through the use of the Atlas V Secondary Payload Carrier (SPC) and/or Internal Payload Carrier (IPC). In 2002, Lockheed Martin sought and was awarded two contracts by the National Reconnaissance (NRO) Office of Space Launch (OSL) to continue the development of the SPC concept. The contract tasks included developing the concept to a preliminary design review level, and an assessment of the effects of the presence of the SPC on the primary payload. Work accomplished on the SPC design since that time culminated in a PDR in February 2003 and a final out-brief on coupled loads results, separation analyses, and expected SP environments to the OSL customer in June 2003. In addition to the SPC, Lockheed Martin developed a concept for an Internal Payload Carrier (IPC) to permit efficient flight of smaller, single secondary payloads. This paper presents the design approach used in developing the SPC and the IPC and addresses technical and programmatic issues encountered during the development phase, as well as the associated solutions to those issues. The paper includes the current design status, features, and capabilities of the SPC and IPC, and how they integrate with the Atlas V launch vehicle and the primary payload.