Functionality

The SCOS-2000^® kernel provides the processing expected for a spacecraft control system, including:

System processes monitoring and control
System static/dynamic configuration management
Users management
Events/Actions management
Redundancy management
Run-time database management
Packets filing, distribution and retrieval, including population of the long-term archive
Files archive management
Telemetry reception, quality/completeness checks and packets extraction
Telemetry modeling, processing, monitoring and visualization
Commands modeling, editing, validation and encoding
Commands release and verification
On-board S/W images management.

The system supports CCSDS telemetry and telecommand packet standards, and the ESA packet utilization standard (PUS). In particular, the processing of all PUS data types and different types of packets is supported, including also the modeling and specialized support of the most important services (such as the report based verification and the on-board mission timeline management).

SCOS-2000^® typical configuration is as a distributed system, running across a network of workstations, although it might scale down to a minimal "SCOS-2000^® in-a-box" (just one workstation) configuration for very simple missions or for training purposes.

The architecture follows the client/server paradigm, with some degrees of freedom on placement of server and client components to comply with different levels of required performance. Fail-over design is also built-in at server level.

The usual deployment of the SCOS-2000^® based systems involves two or more independent chains. Each chain is composed by a main server and several clients attached to it. Only one of the chains is allowed to have the operational control at any given time. This control can be transferred from one chain to the other either explicitly or as the result of a fail-over. Clients can also dynamically switch from one server to another, thus enabling load balancing and warm redundant configurations.

The functionality covered by the SCOS-2000^® kernel can be further extended by means of the so-called 'add-on' systems. These are extensions to SCOS-2000^® that are delivered separately from the main kernel and interact with it by means of well-defined interfaces. The currently available add-on systems include:

The Web-RM Clients, supporting the remote visualization of the MCS operational data. This set of Java based applications, accessing a SCOS-2000^® based system via its CORBA based external interfaces, enables a remote user to display telemetry parameters as well as other operational data (e.g. events and command history) in a similar way as for local users. Security of these remote connections is ensured by means of a generic Web Security Gateway.
The Multi-user Configuration & Central Monitoring (MCCM), supporting the Software Support team in the off-line tasks of systems installations and configuration and also in the on-line 'independent' monitoring of the system health during critical operations.
The Generic Data Distribution System (GDDS), supporting the on-request distribution of operational and ancillary data (i.e. any data stored in the SCOS-2000^® Packet or File Archive) to external systems, located anywhere.
The Telemetry Data Retrieval System (TDRS), supporting the on-request generation and delivery of data files containing a chronologically ordered list of the telemetry parameter engineering samples matching the specified set of filter criteria.

There are plans to further extend the functionality covered by the SCOS-2000^® add-on systems listed above. In particular, it is envisaged to cover the increasing demand of operations execution automation by extending the capabilities of the existing external interfaces of the SCOS-2000^® kernel and by delivering a Mission Automation System supporting the automated execution of monitoring and control procedures.

SCOS-2000^® and its add-ons are not limited to the control of satellites during the operations phase: their use can be extended to cover the on-ground testing phase and work as an EGSE (Electrical Ground Support Equipment). The experience gained with the Herschel/Planck Central Checkout System shows that the required extensions can be accommodated by interfacing external products to the SCOS-2000^® kernel.