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Auflistung nach Autor:in "Herpel, Juergen"

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  • Zeitschriftenartikel
    spaceAPPS – A modular approach for on-board software
    (it - Information Technology: Vol. 63, No. 4, 2021) Herpel, Juergen; Schoen, Friedrich; Selegrad, Harald
    Software modularity and partial qualification capabilities are key enablers to produce cost efficient software in highly regulated domains. The modular concept (called spaceAPPS) described in this paper has been developed in the frame of the OPS-SAT project aiming at missions where flexibility is one of the success factors. spaceAPPS implements a novel software architecture for satellites inspired by the Apps concept of modern smartphones. In the European space domain the operation of a satellite is based on a set of 18 services. Accordingly, in spaceApps these services are mapped to individual Apps. This is not a one-to-one mapping which means that one App implements one or more services. During OPS-SAT ground testing it was demonstrated that functionality could be easily added through a new App or updated through replacing an existing App. Also during OPS-SAT ground testing it could be shown that a failing UserApp did not impact the basic apps to operate the satellite. Thus, it is possible to run applications of different criticality on the same platform. With operating systems supporting time and space separation the risk of failure propagation can be further reduced. The implementation of a partial validation approach, i. e. testing of third-party Apps in a representative environment and not running the validation on the target platform is feasible but was not demonstrated.
  • Zeitschriftenartikel
    Towards modular and scalable on-board computer architecture
    (it - Information Technology: Vol. 63, No. 4, 2021) Kulau, Ulf; Herpel, Juergen; Qedar, Ran; Rosenthal, Patrick; Krieger, Joachim; Schoen, Friedrich; Masar, Ivan
    The demand for satellites and space systems with ever-increasing avionics requirements is constantly growing, whether in the field of satellite communications or earth observation. Traditional architectures for Data Handling Systems (DHS) on satellites are reaching their limits in terms of flexibility, interoperability and reusability, while slowing down the innovation cycle due to costly qualification. With regard to commercial and industrial solutions, it is evident that ‘plug and play’-like systems based on open standards can overcome the above-mentioned disadvantages. For this reason, this paper describes how open standards could affect the architecture of future satellite DHSs. In particular it shows an transition path from the traditional federated architecture to a centralized but modular architecture based on adapted industrial standards.