Esa Bulletin February 1998 [antikvár]

iss data management systemESA's Data Management System for the Russian Segment of the International Space StationJ. Graf, C. Reimers A. ErringtonESA Directorate of Manned Spaceflight and Microgravity, ESTEC, Noordwijk, The NetherlandsRole of the Data Management SystemThe first modules of the International Space Station (ISS) will be the Functional Cargo Block (FGB, built by Russia and financed by NASA), NASA's Node 1 and the Russian Service Module. As the Service Module has to be autonomous from the beginning of Its orbital life, it carries its own Data Management System (DMS-R).In October 1997, two flight units of the Data Management System (DMS-R) for the Service Module of the Russian Segment of the International Space Station were handed over by ESA to the Russian Space Agency (RKA) for use by RSC Energia, the prime contractor for the Service Module and the entire Russian Segment. The Data Management System was developed and manufactured in Europe by an industrial team led by Daimler-Benz Aerospace (DASA) in Bremen, Germany, under a contract placed by ESA's Directorate of Manned Spaceflight and Microgravity in Noordwijk, The Netherlands. The project is governed by a cooperative agreement between ESA and RKA.This is the first delivery of ESA flight hardware within the International Space Station Programme to another International Partner. It will be launched with the station's third assembly flight, in December 1998.Ultimately, the Data Management System will not only control the module Itself, but also perform overall control, mission and failure management of the entire Russian Segment, such as:-system and subsystem control, especially guidance, navigation and control-mission management and supervisory control by ground and crew-management of onboard tasks and failure recovery-time distribution, time tagging and synchronisation-data acquisition and control for onboard systems and experiments-exchange of data and commands with the other parts of the stationIt will also provide overall guidance and navigation for the entire station.Overall DMS-R ConfigurationThe Data Management System architecture of the Russian Segment and its interfaces with the overall International Space Station Is shown in Figure 1. Ten MIL-STD buses provide the Interconnectivlty between the various elements and equipment. The ESA-provided Service Module onboard units are:-Two Fault Tolerant Computers (Figure 2): a Control Computer and a Terminal Computer.-Two Control Posts (Figures 3 and 4) for command and control by the crew via the DMS-R, and for commanding experiments and the European Robotic Arm (ERA), which Is also being developed by ESA under a cooperative arrangement.A more detailed block diagram of the Service Module Data Management System is shown In Figure 5. The Control Computer and Terminal Computer have built-in redundancy to provide the required failure tolerance. The Control Posts can be configured to execute different, dedicated tasks or to operate in redundancy mode.The application software for the onboard computers is being developed by the Russian Service Module contractor, RSC Energia, using an ESA-provided Ground System, which provides the hardware and software environment to support software design, development, simulation, test and validation. It Is also being used to Integrate hardware and software Into the Service Module Flight Model.Principles and implementation of failure toleranceThe Control Computer and the Terminal Computer feature a fault-masking architecture and are single-failure tolerant.