Instrument, Spacecraft, and Launch Overview

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Instrument, Spacecraft, and Launch Overview

• Joan Howard
• Ball Aerospace

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Instrument Requirements
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(No Transcript)
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Ball Heritage

• Currently building SIRTF CTA and instrument which
  uses GeGa FPAs
• Past CDR in subassembly test
• No major technical showstoppers
• IRAS flying successfully
• very similar from a cryo design - only smaller
• Conceptually simple design
• simple electronics, tested FPAs, small/few
  element optics, but.
• Cryo design never simple

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Spacecraft Requirements

• Low Cost - less than 15M?
• Accept gt125 kg instrument
• Provide gt 30 Watts of power to payload
• Pointing Stability lt 24 seconds per data
  acquistion
• Fit into selected Launch Vehicle
• Data Storage 200 Mbytes

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Spacecraft Key Performance Requirements
Description X-12M SMEX LITE SA-200S MiniSta
r Spacecraft Bus Mass 65.6 kg 75kg
98kg Payload Mass Capability 200
kg 91kg 200kg 180kg Available Payload Power gt
100 W 150W 60W 17.5W ACS Configuration 3-axis
stabilized 3 axis zero momentum Gravity
Gradient Attitude Knowledge 28
mrad 5mrad .5 degrees Attitude Control 32
mrad 96mrad 10 degrees Payload Data Storage
256 Mbytes 130 Mbytes 8Gbyte 3Mbytes Communic
ations S-Band S-Band S-band S-band Telemetry
Rate 4Mbps 2.25Mbps 10Mbps 1 Mbps
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Equipment Shelf Provides Ample Area For Subsystem
Units
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S/C Selection

• Meets minimum requirements
• Lowest total cost
• nearly all COTS buses will need changes
• integration issues
• heritage of performance technical, cost,
  schedule
• Willing to work with team
• Selection not mandatory for 1st round - a
  solution, not the solution needed

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Issues/risks/options

• Need good story for aperture cover - esp. after
  WIRE
• Light shade a key driver in itself and for cryo
  design
• Star tracker vs. gyro
• battery size vs. eclipse
• CPU capabilities/memory - on orbit computation
  vs. downlink
• configuration drivers LV, COTS, star tracker
  location, timeline, launch date

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Launch Options