PACS IHDR

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PACS IHDR

• Model Philosophy, Budgets, Interfaces and IID-B

Reinhard Katterloher
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Configuration and Development of PACS Instrument
Models

• Flight Instrument consists of 1 cryogenic FPU, 4
  electronics boxes (units) at ambient temperature,
  1 set of WIH
• CQMAVM Instrument consists of 1 cryogenic FPU,
  4 electronics boxes (units) at ambient
  temperature, 1 set of WIH
• Flight Spare philosophy demands 1 cryogenic FPU
  (which is the refurbished CQM unit), and
  electronics spare kits
• Development program, performance verification and
  environmental qualification of Units is taken
  care by the individual manufacturers
• For each Unit a dedicated Development and Test
  Plan (covering all AIV activities on Unit level)
  is issued and enforced
• AIV of the different models on instrument level
  starts after delivery of the Units to MPE

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Model Philosophy (deliverables to ESA are marked
in blue)
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CQM-FPU and AVM-WE characteristics compared to PFM

• FPU CQM is a nearly FM representative FPU Unit
• Complete optics, all mechanisms, all sensors
• Blue spectrometer array 12 modules instead of
  25
• Red spectrometer array 11 modules instead of 25
• Blue photometer array 8 sub-arrays (2 near
  perfo.) of 8
• Red photometer array 2 sub-arrays (1 near
  perfo.) of 2
• AVM electronics is built with commercial grade
  components, no redundancy, DECMEC, BOLC and SPU
  are not form fit with FM
• CQM wavelength calibration program cannot be
  executed to the same accuracy as planned for FM
  due to schedule limitations
• EMC tests during CQM ILT and on system level
  (EQM) planned

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Functional Properties of Units (deliverables to
MPE)
Unit Model status
FPU STM (mass, size, thermal, ext. alignm.) CQM (full repres. of FM, 50 Ge-arrays) PFM (full flight representative) delivered
DPU AVM (functional repres. of FM, FFF) PFM (nom and red part) QM (functional repres. of FM, for ILT FS) delivered
SPU AVM (functional repres. of FM) EM (functional repres. of FM, for ILT FS) PFM (2 identical boxes nom/red) delivered
DECMEC AVM Simulator (supports electrical S/W performance verification)EM (1MEC2DEC)QM (1MEC1DEC, upgrd. requ. for ILT FS)PFM (2MEC2DEC in 1 unit) delivered
BOLC BOLC Simulator (supports electr.S/W ver.)QM1 (supports FPU ILT performance verif.) QM2 (full QM, for initial FM, for ILT FS)PFM (full flight representative) delivered
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Combination of Units during ILT Phases
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FPU Schematic and Interfaces
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Mechanical interfaces of FPU OB and WE SVM

• The PACS FPU is mounted on the OB with 3 CFRP
  feet
• The mechanical Interface is fully described in
  the drawing
• PACS-KT-ICD-0000W1 issue 27 draft dated
  04-07-2003
• The FPU ICD drawing is annex to IID-B
• The bolting scheme of BOLC QM to SVM is not
  identical with FM
• The mechanical interfaces of other WE FM boxes to
  SVM are given in the relevant PACS Interface
  Control Drawings
• WE FM ICDs are annex to IID-B
• Change requests are issued for WE AVM boxes

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Thermal Budget and Interface FPU - S/C cryostat

• FPU requires two temperature levels- level 0 at
  nominal 1.7K (max. 1.75 K accepted)- level 1
  around 4K (max. 5.0 K accepted)
• Other temperatures inside the FPU are produced
  autonomously (2.2K blue array/ 0.3K bolometers)
• Thermal coupling to cooling level 0 via 4 heat
  straps
• Thermal coupling to cooling level 1 via 3 heat
  straps
• FPU is thermally decoupled from OB by CFRP feet
• Thermal loads and final heat fluxes are
  calculated using the PACS TMM combined with the
  cryostat TMM

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Steady State Heat Dissipation (table from PACS
TMM)
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Harness Interface FPUWES/C and Electrical Budget

• Harness is specified in PACS-MA-SP-001-V3.2,
  annex to IID-B It consists of- total inside
  CVV 1060 wires 255 shields - total outside
  CVV 1060 wires 255 shields 15
  overshields- Warm Interconnect Harness (specs.
  given in PACS-CL-RS-010)
• Power consumption of WE see separate table
• Science data rate in PACS prime mode is 130 kbps
  max (120 kbps average per day)

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Power Consumption on SVM (present allocation is
120 W, CR-0033_V3 pending, demand for LCL class
III)
Table of maximum average power and short and long
peak power demand is provided in IID-B CR-0033_V3
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Mass and Size of Instrument Units
Project code Instrument unit Dimensions (mm)length x width x height Nominal mass (kg)
FPFPU Cold focal plane unit See configuration drawings annex IID-B 73.6
FPDECMEC Detector control and mechanism control unit EM 560x318x304 FM 560x318x305 TBC 23 (TBC)
FPBOLC Bolometer and cooler control unit QM 328.5x300.2x314.3 FM 382.5x289x333.5 incl. connect. backshell 499.5x289x376.9 TBC 15.35
FPDPU Digital processing unit 274x258x197 including fixation feet 240x258x197 exclud.f.f. 6.62
FPSPU nom.redu. stacked Signal processing unit AVM 280x240.5x350 FM 270x221x186 TBC 7.0
FPWIH Warm interconnect harness Length AVM 2000 Length FM 1300/1500 1.5 TBC
Total mass FM (allocation 130 kg) 127
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Current IID-B Status

• Status of open CRs submitted or still to be
  written will be given under topic PA/QA
• Status of open RFWs submitted or still to be
  written will be given under topic PA/QA
• Lot of figures and few tables need to be replaced
  according to progress in instrument development
  and have to be included in the very next version
  of IID-B (many of the figures are ready for
  submission)
• Missing figures, drawings and all text additions
  can be expected from PACS within the next two
  weeks

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Urgent Pending Activities w.r.t. Documentation

• Update of IID-B has highest priority
• Next issues of AIV Plan and Test Plan are due
  (PCD draft 7 up to date)
• Definition of the optimized ILT test sequence and
  consolidation of test steps need further
  technical discussions
• Definition of detailed test procedure for the
  CQMAVM ILT in progress already, issueing of the
  document Test Plan will be started immediately
  after AIV Plan is completed
• Selection of building blocks out of the ILT
  program for the EQM test program has to be
  started soon (test steps adapted to EQM
  constraints)
• Approval of RFW0003 expected soon, qualification
  program of black paint needs to be finished
  because manufacture of FM structure has started