Summer Projects Review: Current Status. ADCS ADCS calibrated in uniform magnetic field using support...
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Transcript of Summer Projects Review: Current Status. ADCS ADCS calibrated in uniform magnetic field using support...
Summer Projects Review:Current Status
ADCSADCS calibrated in uniform magnetic field using support hardware to mimic the computer onboard the satellite.
The mV/gauss change is now known:•1-3mV/gauss for the y axis•30-52mV/gauss for the x axis•34-53mV/gauss for the z axis
Pointing variation for the z axis has been calculated, α=2.891° or 0.0505C.
Current passing through the Set/Reset strap on the HMC1053 as its resistance changes due to the ambient temperature has been calculated. This is directly linked to how much power the Set/Reset will draw.
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
1.11amps at 4.5Ω (typical)
Set/Reset circuit on ADCS
Set/Reset strap on HMC1053
50 nanoseconds of peak current (>400mA)
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
• up to 6 solar arrays
• 3 battery charge regulators (BCRs)
• 3 power buses, 2 regulated (3.3V and 5V) and a raw battery bus
• Bus over-current protection
• Battery under-voltage protection; if the battery voltage drops below 6.5V, the output buses are disable until the battery voltage reaches 7.5V
• Telemetry and telecommand via an I2C bus
• Power consumption <0.1W and weight 152.96g
• Estimation of power produced when in sunlight 2.11W (solar array efficiency 17%, AM0 = 1.35kW/m2)
• Battery capacity 1.25Ah
1U CubeSat Electrical Power Supply from Clyde Space
PSU Main Features
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
Current Status• Solar array equivalent circuit and battery simulator connected successfully
• I2C bus has been used successfully
• BCR1 has been damaged – testing has been suspended
Testing of the PSU
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
GOALS
Test flight and dev board Incomplete
Specify physical interfaces Complete
Set up and Software Development Environment Complete
Write ADCS software Incomplete
Fully interface subsystems Incomplete
OBDH
KEY FACTS
Majority of the board runs on 3.3V logic
Board includes +5V and +3.3V VCC power buses
Clock speed of MCU is 7.378 MHz
Power consumption is around 0.01 W
Mass (with physical interfaces) is 90g
Tolerances are -40 to +85°C
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
Summer Review6th Aug. 2008
SRCSPACE ACADEMY
InterfacingPhysical interfaces are via the cubesat kit system bus
Multiplexing and a PowerFET are needed for the ADCS interface.
Transceiver does not plug into the cubesat kit bus.
Modes outlined.
PSU
OBDH
COMS
PAY
SD
CAM
NORMAL OPERATING PROCEEDURE
ADCS
beacon
Summer Review6th Aug. 2008
SRC
Sunlight
Eclipse
Launch
Safe
SPACE ACADEMY