Section 7 Part 2 Mechanical Accommodation

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Section 7 - Part 2Mechanical Accommodation
. . . Pete Alea Cengiz Kunt Keith Tompson Swales
Aerospace
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Agenda

• Derived Mechanical Requirements
• Instrument Interface Definition
• Spacecraft Configuration
• Spacecraft Accommodation
• Structural Analysis
• Spacecraft GSE Alterations
• Issues/Concerns

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Spacecraft Mechanical Requirements

• Accommodate the Hyperion Sensor Assembly (HSA)
  with a NTE mass of 35 kgs two electronics boxes
  with a NTE mass of 7.0 kgs each
• The HSA shall be hard mounted by way of an
  instrument shelf to the S/C nadir deck on the -Y
  side with 12 fasteners. The HSA mounting surface
  shall be flat to within .25 mm provide for a
  4.84 0.05 inclination in the -Y direction
• The HSA hard mounted fundamental mode shall not
  be less then 70Hz
• TRW shall provide the interface drill template
  for the mounting hole pattern. The drill fixture
  alignment to the S/C is 0.01 degrees, using
  tooling pins and optical alignment cube.
• The HSA FOV shall be clear of all S/C
  obstructions within 15 cone about optical
  centerline 30 cone about solar-calibration
  centerline
• Provide on orbit thermal stability within 10
  arcsec
• Provide the HSA with a dry nitrogen purge
• The Hyperion to S/C Interface Control Drawing
  defines the location mounting hole pattern for
  the electronic box assemblies

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Spacecraft Configuration

• EO-1 Spacecraft Configuration with Hyperion
• Height of X-Band and S-Band Antennas increased to
  maintain RF FOV
• ALI FOV requirement was reduced based on
  stray-light analysis

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Spacecraft ConfigurationEO-1 Spacecraft
Configuration with Hyperion (continued)
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HSA Interface Definition
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Fields of View
Solar Cal intrusion into ALI FOV
S-Band Intrusion
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Clearance with ALI FPE
HEA/CEA Clearance with ALI FPE Radiator
HEA/CEA clearance w/ ALI Pallet
HEA clearance w/ FPE Radiator
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Hyperion Accommodations
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HSA Shelf Assembly Details
Mounting shelf removed for clarity
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HEA/CEA Baseplate
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Spacecraft Design Limit Loads
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Hyperion Support Structure
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Hyperion Subsystem Frequency
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Spacecraft Dynamics
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HSA Stress Margins
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S/C Stress Margins Update
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Spacecraft GSE Alterations

• The spacecraft lifting points and sling will
  require modifications to allow for vertical
  lifting.
• All outrigger hardware shown will need to be
  installed and removed during vertical lifting
  ops. All new GSE hardware is non-flight.
• Solar array assembly will not be impacted by GSE
  changes.

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Spacecraft Accommodations Summary

• Provided shelf over Z launch restraint for
  mounting HSA
• Provided baseplate on nadir deck for HEA/CEA
  mounting
• Rotated and raise X-Band S-Band antenna booms
  on nadir deck
• Modification of spacecraft lifting sling and new
  outrigger hardware required to replace lifting
  points blocked by HSA support structure
• ALI integration time will increase due to
  hardware addition
• Spacecraft alignment requirements increased
  substantially by HSA addition
• Overall S/C IT impacted by hardware additions.
  Partial obstruction of Z SA launch restraint
  will increase solar array integration time.

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Mechanical Issues / Concerns

• HSA weight growth will negatively effect both S/C
  and instrument loads. Schedule delay due to
  additional testing is likely if weight increases
  or frequency drops further.
• Concern that Hyperion (HSA) fundamental frequency
  may be below 70 Hz (potential loads issue)
• Close coordination with S/C electrical/harness
  group will be required to minimize hardware and
  schedule impacts
• Tool clearance at mounting I/F needs to be
  checked further