AvionicsAAE 450 Spring 2008
Project BellerophonApril 17, 2008
Avionics
Overview AvionicsTelecommunicati
onsVehicle
Antennas
Data Chann
els
Tracking
Ground
Antennas
Data Chann
els
Data Proces
sing
Flight ControlData Processing
Inputs
Sensors
OutputsControls
Power Systems
Source
Supply
AvionicsAAE 450 Spring 2008 1
Electronic Parts: Component RatingCommercial
Class B
Class S
Commercial Requirements Class S Requirements
Infinite production lot size Built one at a time
No burn-in testing Extended burn-in time (up to 240 hours)
No detailed failure analysis Extended failure analysis
No life testing 1,000 hour life test on every lot
No traceability Traceable to the raw materials
> 1% failure per 1000 hours allowed 0.0001% failures per 1000 hours allowed
1 NASA Electronics Parts Assurance Group
AvionicsAAE 450 Spring 2008 2
Telecom Analysis: Doppler ShiftFrequency Shift due to Doppler Effect
0 2000 4000 6000 8000 10000 12000 14000 16000 180000
20
40
60
80
100
120
140
160
180
200
Vehicle Velocity (m/s)
Fre
quen
cy S
hift
(kH
z)
401 MHz
1.45 GHz2.2 GHz
3.0 GHz
AvionicsAAE 450 Spring 2008 3
Telecom Analysis: Data Rate
0 1 2 3 4 5 6 7 8 9
x 107
0
5
10
15
20
25
Data Rate (bps)
Link
Mar
gin
(dB
)
401 MHz
1.45 GHz
2.2 GHz3.0 GHz
3 dB Margin
Change in Link Margin due to Data Rate
AvionicsAAE 450 Spring 2008 4
Telecom Analysis: Path Length
0 1000 2000 3000 4000 5000 6000 7000 80000
5
10
15
20
25
Path Length (km)
Link
Mar
gin
(dB
)
401 MHz
1.45 GHz
2.2 GHz3.0 GHz
3 dB Margin
Change in Link Margin due to Signal Path Length
AvionicsAAE 450 Spring 2008 5
Telecom Design: Vehicle Link Budget
Item Value Units
frequency 401 MHz
transmitter power 5 Watts
transmit antenna beamwidth 60 deg
transmit antenna diameter 0.87 m
equiv isotropic radiated power 12.3 dB-W
propagation path length 5,000 km
receive antenna diameter 10 m
receive antenna beamwidth 5.24 deg
data rate 9,600 bps
signal to noise ratio 50.82 dB
carrier to noise density ratio 90.64 dB-Hz
bit error rate 0.00001 ---
implementation loss -2 dB
final margin 39.20 dB
Simplified Link Budget
Minimum Margin:3 dB
Vehicle Margin:39.2 dB
AvionicsAAE 450 Spring 2008 6
Range Safety Officer (RSO)– An individual who is responsible for the remote destruction and
consequent flight termination of the launch vehicle should it be deemed a hazard.
RSO Responsibilities– Evaluate the launch vehicle design as well as oversee the manufacturing
process. – Monitors the launch vehicle and environmental conditions prior to
launch. – Monitors and tracks the launch vehicle during flight.
Hiring– Budget $1,700 per launch, assuming a 5 day period.
Range Safety: Personnel
AvionicsAAE 450 Spring 2008 7
Flight Corridor– An imaginary zone that exists in a space above the launch range.
Application– Implemented so that if the launch vehicle where to experience a failure
during flight, the vehicle will fall to the ground in an uninhabited area.
Termination– The launch vehicle must be destroyed if it flies outside the
predetermined flight corridor.
Range Safety: Flight Corridor
AvionicsAAE 450 Spring 2008 8
Non-Space-Rated Sensors
Sensor Type Part Number Manufacturer Unit Price
Thermal TS3-85 Cantherm $10.29
Pressure 2000260Measurement Specialties Inc.
$104.06
Flow 26616 Gems Sensors, Inc. $154.95
Force FSS1500NSRHoneywell Sensing and Control
$46.56
AvionicsAAE 450 Spring 2008 9
Space-Rated Sensors
Sensor Type Part Number ManufacturerUnit Price
Thermal S311-641/04Honeywell Sensing and Control
$800
Pressure PPTRHoneywell Sensing and Control
$970
AvionicsAAE 450 Spring 2008 10
Sensor Reliability Analysis: ThermalSensor Company Accuracy Reliability
270 Space Series Honeywell Aerospace
±2.8°C 100,000 Cycles
MCP9700/9700A (non-space-rated)
Microchip ±2°C none
AS-TE (space-rated)
Fluid Components International
± 0.3° C 200,000+ Hours
Various (space-rated)
Measurement Specialties
±0.01˚C 3500 cycles(can be specified)
This table details the reasons for differences in cost.
AvionicsAAE 450 Spring 2008 11
Power Supply: Power Budget
Vehicle Flight Time Balloon Rise Time
Vehicle System
Percent of Operating
PowerPower
(W)
Energy Consumption
(Wh)Mass
(kg)Power
(W)
Energy Consumption
(Wh)Mass
(kg)Payload 5 10 1.04 0.01 10 30.00 0.27Propulsion 35 70 7.25 0.07 0 0.00 0.00Attitude Control 15 30 3.11 0.03 0 0.00 0.00Communications 10 20 2.07 0.02 20 60.00 0.55Command and Data Handling
5 10 1.04 0.01 10 30.00 0.27
Thermal 5 10 1.04 0.01 0 0.00 0.00Power Management
25 50 5.18 0.05 10 30.00 0.27
Total 100 200 20.72 0.19 50 150.00 1.361.5 Safety Factor 300 31.08 0.28 75 225 2.05
200g Payload Case, Silver Zinc Battery, Balloon Launch
AvionicsAAE 450 Spring 2008 12
Power Supply: Battery Selection
LiCF Li SOCl2AgZn
Watt-Hours/Kilogram 130 185 110
Watt-Hours/Liter 160 240 200
Discharge Rate Low Moderate High
Failure Tolerance Low Low High
Cell Voltage 2.95V 3.1V 1.5V
Experience Level High Moderate High
Costs Low Low Low
AvionicsAAE 450 Spring 2008 13
Power Supply: AgZn Battery
AgZn Benefits
Can charge 4 to 6 times in case of scrub
Capable of controlling gimballing, ignition, and range safety subsystems
Silver Zinc (AgZn)Battery Property Value
Weight (kg) 2.3 - 4.5
Volts (V) 1.6 - 1.85
Rated Capacity (Ah) .8 - 800
Specific Energy (Whr/kg) 55 - 286
Energy density (Whr/l) 55 - 262
1http://www.eaglepicher.com/
AvionicsAAE 450 Spring 2008 14
Power Supply: Batteries
Estimate Cost: < $10,000 Weight: 2.3-4.5 kg
Battery Weight Wh/kg Cost
Silver-Zinc (AgZn) 2.3-4.5 kg 110 ~$10,000
Lithium-Monofluoride (Li/CF)
2.3-4.5 kg 130 --------
Lithium/Thionyl Chloride (Li/SoCl2)
2.3-4.5 kg 185 --------
AvionicsAAE 450 Spring 2008 15
Installation Cost
Primary Contractor: Aircraft Electrician
Median Salary1 $40,984.00Work Days per Year 240Income Per Day $170.77Income Per Hour $21.35Billing Rate Per Hour $32.02
At four weeks of billable workInstallation Cost: $7,172.20
1 Salary data from www.salary.com
AvionicsAAE 450 Spring 2008 16
Telecom: Failure Analysis
Sourcesof
Failure
Reliability Factors
For a low complexity system with redundancy1:
Part Class ReliabilityClass B: 98.75%Class S: 99.87%
Assumptions - Simple system - Low radiation dose - Reliability based on a five year mission plan
1 Wertz, 404.
AvionicsAAE 450 Spring 2008 17
First Stage: 6.024 kg total (safety factor=1.2)-wiring: 2kg-sensors 1.02kg-battery 2kg
Second Stage: 30.2664 kg total (safety factor=1.2)
-Telecom: 10 kg -CPU: 0.85 kg-Sensors: 1.02 kg -Range Safety: 9.23 kg-Wiring: 2 kg -IMU: 0.122 kg
-Battery: 2kg
Third Stage: 1.2 kg total (safety factor=1.2)
-Wiring: 1 kg
Mass Budget
AvionicsAAE 450 Spring 2008 18
Launch lock (US Patent 6508437)
Motorized release Explosive Bolt/Spring sequence1 Explosive/Slingshot Sequence
1(Professor Filmer), (International Reference Guide to Space Launch Systems pg 296)
Payload: Launching Options
AvionicsAAE 450 Spring 2008 19
Assumptions Made– The Earth is spherical in shape.– The area where the signal intercepts the Earth is circular.– Neglect any antenna mounting errors or design issues.– Neglect any atmospheric anomalies which may refract the signal.– The signal propagation from a cluster of directional antennas can
be estimated using a omnidirectional antenna.– The signal propagation from an omnidirectional antenna is
spherical in shape.
Signal Projection: Assumptions
AvionicsAAE 450 Spring 2008 20
1Professor Filmer, Purdue University School of Aeronautics and Astronautics
Approximate Ground Equipment Costs1
Radio ($1,200)
Antennas ($500)
Computer ($2,000)
Misc ($500)
Total: $4,200
Example Case: Small Payload Launch Vehicle
LV Ground Track Balloon Ground Track
236.09 km 120.74 km
Mean Propagation Radius
4,995.4 km
Launch Vehicle Tracking
AvionicsAAE 450 Spring 2008 21
Avionics: Cost BudgetUnit Costs
Wiring - Materials $ 500- Installation $ 7,500
CPU $ 10,000 IMU $ 15,000 Sensors (500 each) $ 8,000 Battery $ 10,000 Range Safety $ 20,000 Ground Tracking $ 24,000 Total $ 95,000
AvionicsAAE 450 Spring 2008 22
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