1 SLE is going Operational

CCSDS has developed a set of Recommendations for Space Link Extension (SLE) Services with the aim to provide a uniform cross support capability for agencies who develop interfaces to their facilities in accordance to these Recommendations. SLE services are specified in terms of operations at application level and associated data structures for exchanging space data units between cross-supporting Agencies. ESOC and JPL, initially in the context of cross support of the ESA Integral mission using NASA DSN stations, have implemented a basic set of these recommendations. This consists of the Return All Frame (RAF), and the Return Channel Frame (RCF) services for the return link and the Command Link Transfer Unit (CLTU) service for the forward link. Beyond the Integral project, these services will also be used for the cross support between ESA and NASA/JPL of future missions, and particularly, in 2003, of Rosetta and Mars Express. Although during the parallel ESOC and JPL development, the two Agencies have adopted respectively the role of “service user ” (ESA) and “service provider ” (NASA), the development concept adopted is based on the potential interchangeability of the kernel software (the API element) for the implementation of both “user”/”provider ” interfaces. Thus for example, ESA also developed