Double Star: Table of Contents European Experiment Summary Mechanical Interface Experiment Accommodation Thermal Interface EMC Rationale Grounding Philosophy / Harness Status of Experiment Interface Verification Measurements (Electrical Integration) © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 1 Roland Nord

Double Star: Summary of European Experiments © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 2 Roland Nord

Double Star: Mechanical Interfaces Accommodation Status on Equatorial Satellite (Feb. 2002) ASPOC (location for FoV OK, mechnical details of mounting pedestal not fully clear yet FGM-Electronics (location OK) FGM-sensors (mechanical details tbd) HIA (location for FoV OK, minimum distance to thrusters is sufficient) PEACE-DPU and H(L)EEA (location for FoV OK, minimum distance to thrusters is sufficient) STAFF-PWR, STAFF- DWP/MWF,STAFF Pre-amp, (status unknown, but depicted wrongly in latest drawing) © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 3 Roland Nord

Double Star: Mechanical Interfaces (Cont’d) Interface to the Central Purge supply The interfaces on the experiments and on the spacecraft are defined, i.e. for: HIA (on equatorial ) PEACE-H(L)EEA (on equatorial / polar) NUADU (on polar) The component specification for the Cluster used hardware as well as the material property parameters were given to CSSAR Samples of hardware can be made available Implementation on the satellite is tbd © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 4 Roland Nord

Double Star: Accommodation (1) © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 5 Roland Nord

Double Star: Accommodation (2) © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 6 Roland Nord

Double Star: Accommodation (ASPOC) ASPOC is proposed to be accommodated on a very stiff pedestal bolted via an integral base-plate to the main equipment platform © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 7 Roland Nord

Double Star: Example: Cluster Drawing Detail © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 8 Roland Nord

Double Star: Thermal Interfaces Report on the results of the detailed thermal analysis incl mission prediction for the experiments is issued soon? The status of satellite thermal hardware baseline w.r.t. blanket foil type, MLI design, fixation method, internal grounding, heaters, thermostats, radiators: was not made known to the European experimenters Special thermal blanket interfaces to be defined soon: on ASPOC (local blanket provision and I/F to the tbd -Z side satellite blanket on lower platform, if existing) on HIA (local blanket provision and I/F to the tbd satellite payload belt blanket, if existing) PEACE-H(L)EEA (local blanket and support frame fixation to the payload belt blanket, if existing) NUADU ((local blanket provision and I/F to the tbd © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 9 Roland Nord

Double Star: Outside Thermal Finish Overall Conductivity Baseline design for European instruments: Tight fit local thermal blankets with conductive outer surface to be applied to the protruding parts of the sensors and the sensors on the booms Conductive coating: In-Sn Oxide, L300 or Electrodag 501 Bonding of these blankets to the satellite structure and / or the satellite thermal blankets Information on thermal materials was provided to CSSAR (Kapton, Mylar foils thermal blanket attachment procedures etc) Status in China: Baseline concept for the conductivity of the solar generator is established No information, however, is available for the baseline concept of the overall outside thermal closure and how to achieve near 100% outer surface conductivity © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 10 Roland Nord

Double Star: Overall EMC Concept / Harness (1) Baseline design rationale for the Cluster mission: Minimalisation of AC magnetic emissions Spatial separation of power, signal and pyro harnesses Power lines shall be twisted with their returns Power and signal harness shall use separate connectors. If wires of different harness types use the same connector the wires shall be separated by implementation of ground pins in between the signal and power lines respectively pyro lines. Signal lines shall be twisted with the return lead Shields not to be used as return line In connectors the pins of the active signals shall be kept as close as possible to their returns © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 11 Roland Nord

Double Star: Overall EMC Concept / Harness (2) Baseline design rationale for the Cluster mission: Minimalisation of AC magnetic emissions Box internal connection of secondary power return to structure ground (in Cluster this was done at signal ground rail) Signal return currents to be routed as shortly as possible to box internal ref. ground. (Cluster: to the signal ground rail) Return of shield charge currents to ground close to the source (in Cluster to the signal ground inside unit) TSP-Shield termination only on signal source side, open connection on receiver side (avoidance of charging current return via structure; minimise structure induced noise Overall cable shield connected to the connector back shells and every 20 cm to structure ground (platform) © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 12 Roland Nord

Double Star: Grounding Philosophy 1 Baseline design for Cluster instruments: Grounding with ground rail as Signal Ground Reference The TSP shields must be connected on the signal source side only to keep the charging current line as short as possible © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 13 Roland Nord

Double Star: Grounding Philosophy 2 Grounding of Signal Ground to Box Structure: TSP Cable Shield is Grounded to Signal Ground The TSP shields are connected on the signal source side only to structure to keep the charging current line minimum For the Cluster experiments this concept would mean a minor modification in the I/F connector: a wire bridge between structure and signal ground pins © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 14 Roland Nord

Double Star: Grounding Philosophy 3 Internal Grounding of Signal Ground to Box Structure: TSP Cable Shields are Connected to Connector Back Shell The TSP shields must be connected on the signal source side only to keep the charging current line short and thus AC fields low For the Cluster experiments this concept would mean a box internal minor modification close to the power converter: connection of secondary power ground to structure. © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 15 Roland Nord

Double Star: Experiment Electrical Integration Baseline of for I/F Measurements Interface verification Double Star PDMU (EM / FM) Versus Experiments shall be made manually (using scopes and multimeters) Use of the modified and updated Cluster II integration procedures (now available as “Word”-files) Planned measurement program. 1 Bonding Resistance Check 2 Pin Grounding Continuity Check 3 Unconnected Harness Check for dangerous voltages (all PDMS subsystems running) 4 Power Interface Check (in-rush current, current level, converter synch) 5 Signal and Command I/F-Check 6 Inter Experiment Link I/F-Check (check for dangerous voltages only) 7 Integration Status Check © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 16 Roland Nord

Double Star: Experiment Electr. Integration (cont’d) Preconditions for the Integration Start Following test activities have to be performed prior to the experiment integration PDMS acceptance test incl. test protocols etc (satellite contractor) The PDMS-experiment harness and IEL continuity test incl. test protocols (satellite contractor) Intra experiment harness continuity check (experimenter) Availability of a complete and debugged set of control files for the switching of the PDMS / satellite functions the switching of the experiments which are compiled on the Central Check-out Computer © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 17 Roland Nord

Double Star: (Cont’d) S/C switch-on power up dedicated experiments Comprehensive Information on: S/C Command Sequences / Control Files for S/C switch-on power up dedicated experiments Switch into Primary mode Switch into Redundant mode Cross coupling Command Spin Rate Change is needed to prepare the electrical integration procedures properly. © Astrium Double Star Mtg, CSSAR, Beijing, 20 / 25 May 2002 Page 18 Roland Nord