Joachim Kehr | German Aerospace Center (DLR), Project Management Agency (original) (raw)

Joachim Kehr

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Papers by Joachim Kehr

Die COL-CC Kontrollzentrums-Verantwortlichkeiten werden vor dem Hintergrund der ESA Rats-Entschei... more Die COL-CC Kontrollzentrums-Verantwortlichkeiten werden vor dem Hintergrund der ESA Rats-Entscheidung vom 16. Dez. 98 für die Implementierung eines dezentralisierten Kontrollzentrumskonzepts dargestellt

For the 40 th anniversary of the Helios-1 launch (10 th December 1974) and as the former Helios m... more For the 40 th anniversary of the Helios-1 launch (10 th December 1974) and as the former Helios mission operations manager, I want to salute the – in my opinion – most underestimated experiment of Helios: The celestial mechanics experiment (NSSDC ID Helio-B-14, PI: W. Kundt, University Hamburg, OI: W.G. Melbourne, NASA-JPL, Ref. 1). The experiment was meant "to use the tracking data to obtain a detailed spacecraft orbit and improved knowledge of the orbital elements of the Earth-Moon system and general relativity parameters" (NSSDC description). According to the experimenter (Ref. 2), the experiment was sacrificed for the success of the other Helios experiments because the distance measurements between Earth and spacecraft ("coherent ranging") had to be discontinued after eight months (on both spacecraft) since the (coherent) ranging transponder failed and the transponder's prime travelling wave tube (TWT) amplifier failed at the same time the backup TWT had ...

This paper describes the In-Orbit Infrastructure Ground Segment (IOI GS) required to support the ... more This paper describes the In-Orbit Infrastructure Ground Segment (IOI GS) required to support the Columbus Laboratory payload operations and system control functions as part of the Columbus Program. The Columbus Program and the corresponding ground infrastructure have changed significantly since the Program was first initiated. However, this paper concentrates on the IOI GS in the configuration which was defined at

The initiation of the (German-) nationally funded control center for manned spaceflight operation... more The initiation of the (German-) nationally funded control center for manned spaceflight operations triggered by the invitation of President Reagan to ESA, Japan, and Canada in 1984 to join the International Space Station Freedom Program is recalled. The requirements for a Manned Space-Laboratories Control Center (MSCC) as defined at the beginning of the planning and construction process in 1987 and the resulting modifications during the various programmatic scenario changes on NASA and ESA side between 1987 and now are presented. The validity of the original requirements with respect to the current scenario, which asks for a logical evolution from the execution of the D-2 mission in January 1993 via the European Columbus Precursor flights (in particular the E-1 mission) towards Columbus Attached Laboratory (APM)-operations by the end of this century are discussed. The resulting tasks of the MSCC for the various missions, the current configuration, and the ensuing operations concept ...

Ph D Thesis Technische Univ Munich Fakultaet Fuer Maschinenwesen, 1987

ABSTRACT Material degradation procedure is studied on two different solar generator cells from HE... more ABSTRACT Material degradation procedure is studied on two different solar generator cells from HELIOS and SYMPHONIE on a time span of 10 yr. Silicon solar generator behavior is analyzed relative to its radiation resistance by a correlation procedure. Degradation spectra and coefficients obtained experimentally are converted into monoenergetic equivalent fluxes. Main degradation parameters considered are radiation effects, temperature, and surface damage. For determination of power losses by surface degradation an optical model of the system surface glass/junction/cell is developed.

Wie Columbus fliegen lernte, 2010

Space Operations: Experience, Mission Systems, and Advanced Concepts, 2013

Resumen The European Module Columbus of the International Space Station (ISS) is planned to be la... more Resumen The European Module Columbus of the International Space Station (ISS) is planned to be launched 2004. For its exploitation phase as well as for the early utilisation of the Space Station starting from 2003 onwards the operations procedures are now being ...

ABSTRACT DLR wissenschaftliches Kolloquium

The Columbus Orbital Facility -Control Centre (COF-CC) will be responsible for the systems monito... more The Columbus Orbital Facility -Control Centre (COF-CC) will be responsible for the systems monitoring and control and payload operations co-ordination of the COF, which is part of the European contribution to the International Space Station. The COF-CC architecture is to be implemented making the maximum use of commercial off-the-shelf hardware and software for both the computing and communications environments, as well as Project-based "legacies" coming from the space segment development. A component based architecture will be implemented according to "de-facto" industry standards and will use extensively Web based technologies. All these factors will provide operators with a highly integrated and flexible workspace, support the automation of numerous routine tasks, and will contribute to a reduction of procurement and maintenance costs.