CNES’07 Mars Premier Peer Review
Rendezvous and Sample Capture
OS Beacon Electronics
And Power System
Mark Schaefer
April 17, 2002
Author Name
CNES’07 Peer Review 4/17/02
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Requirements
 UHF Beacon that fits inside 20cm OS
 24 cm is resonant at UHF
 Serviceable
 Compatibility with Electra
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Compatible Channel
Modulation if any
Canister Open Loop Recording Mode or Carrier Tracking
Navigation requirements for Doppler measurements
 Requirements for tracking by CNES 07 only and for two Orbiters
 Beacon Frequency Stability
 Electra SSO or USO Stability
 1000km range capability with Electra on CNES 07
 Interval required with continuous contact
 Antenna Pattern related
 Does not interfere with Netlander science
 Mission Phasing
 Frequency compatibility
 Receiver Capture and Sensitivity degradation
Author Name
CNES’07 Peer Review 4/17/02
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Requirements
 Battery powered (solar cells not compatible with OS optical properties)
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Primary/Secondary
Charging requirements
Monitoring requirements
Temperature survival
 Transmit disabled until OS is ejected
 2 month maximum powered lifetime after OS ejection
 Acceptable degradation over time
 Survival life
 9 month cruise
 1 year in Mars orbit before ejection
 Environmental Requirements
 Launch/Ejection/Capture Vibration
 NonOp and Operating Temperatures
 EMC
 Parts
 Grade 2 Plus?
 Radiation
 Converting Industrial Use Beacon to Flight Qualified
Author Name
CNES’07 Peer Review 4/17/02
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JPL Internal Concept
 WAG Derived by Eric Arched based on previous experience with DS-2
and OS beacon electronics for RDF (Radio Direction Finder) concept
 WAG reviewed (at WAG level) by Chad Edwards
 Cost Estimate assumed Transceiver with Solar Cell Rechargeable
Batteries using Patch Antennas for 2 to 3 year mission
 Not applicable to present approach
 Commercial Beacon upgraded for Flight could be
 Order of Magnitude lower cost
 Qualified at JPL
Cost Comments
Batteries (Class A)
900 Batteries are 6kg
Battery Charge Controller
500
lien: E. Romo indicates Grade 2+ parts required, 1 STM, 1
Beacon Electronics (Class C) 2300 EM, 1 FM, 1 FM Spare
Electronics I&T 1700 Includes Env Tests
Total $K 5400
Author Name
CNES’07 Peer Review 4/17/02
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Trades in Work
 Commercial UHF beacons
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ELTA Buoy Beacon (built Mars Balloon Relay for MGS)
SAW Oscillator
DS2 inheritance
Others
 Antenna configuration
 Patch or Multiple Patches
 Spherical Dipole
 Loop or Multiple Loops
 Batteries: Primary/Secondary
 Battery Charger vs. Battery Monitor
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Lithium
Lithium
Lithium
Lithium
Others
Author Name
Thionyl Chlorate
Sulfur Dioxide
Manganese Dioxide
Carbon Monoflouride
CNES’07 Peer Review 4/17/02
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Trades in Work
 Soft vs. Hard Surface and Structure
 Issue for capture safety
 Thermal Insulation
 Surface material
 Internal filler
 Reflective Coatings
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Compatible with albedo for camera
Maintains internal temperature
Compatible with Antenna
Compatible with Orbiter contact during capture
 S/C or Internal Survival Heater
 Maintains Battery and electronic components during Cruise
 Beacon Transmit Duty Cycle
 Power Consumption vs. probability of detection
Author Name
CNES’07 Peer Review 4/17/02
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Path to Concept Review
 Define Mission Goals and Scenario
 Define Mission/Hardware Requirements
 Finalize trades on UHF beacon source, antenna configuration,
batteries, structure
 Develop concept design late May
 Develop Cost, Workforce, and Schedule early June
 Develop industry partners and JPL Team connections
Author Name
CNES’07 Peer Review 4/17/02
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