Space Systems Group
THE AEROSPACE CORPORATION
El Segundo, CA 90245-4691
SPACE AND MISSILE SYSTEMS CENTER
AIR FORCE MATERIEL COMMAND
Contract No. F04701-93-C-0094
Aerospace Report No. TOR-96(1571)-3
M. A. Rich, Director
|C. A. Sunshine, Principal Director|
Satellite Control Network Development Subdivision
Satellite Control and Spacelift Range Division
Space Systems Group
The information in a Technical Operating Report is developed for a particular program and is not necessarily of broader technical applicability.
The Standard Satellite Control Segment (SSCS) of the Air Force's Satellite Control Network is defined by a high-level requirements document called the SSCS Functional Requirements Document (FRD). The particular version used for the work presented in this document was a draft dated August 4, 1995. The SSCS FRD describes a Telemetry, Tracking and Commanding (TT&C) system that performs telemetry processing, satellite commanding, orbit analysis, spacecraft attitude analysis, general mission planning functions, simulation, and management of system resources. This document presents a reference architecture that encompases the first five of these functions, with some discussion of the ground system status subfunction of resource managment.
A reference architecture is a high-level design describing the system components and interfaces among them. Relationships between the components included in SSCS and external elements are also identified. Implementation details are avoided throughout this document, so the architecture can be applied as widely as possible. The architecture consists of two parts, software and hardware. The software architecture provides: high-level views of the system components and their relationship to each other and to external elements, data flow diagrams that further decompose the basic functions and show how data is passed between processes, a control flow diagram that indicates the temporal relationship between processes, and functional Application Program Interface (API) definitions providing more details about the mechanisms that pass data between processes. The hardware architecture uses a series of performance benchmarks to distribute the SSCS functionality among workstation platforms and develop a notional network topology.
The SSCS reference architecture has already been applied in various program office planning activities. Next, the architecture will be used to develop evolution options for the Distributed Command and Control System (DCCS), which will be used as the basis for the development of a core TT&C system that System Program Offices (SPOs) will integrate into their mission ground systems. This effort will attempt to increase the system's utility and interoperability in ground systems developed by the SPOs. Finally, this architecture will be used to facilitate discussions with TT&C product vendors and their users about the standardization of TT&C architectures and interfaces.