1. ARISSat-1 Critical Design Review Orlando, Feb 15, 2010 Power Management Anthony Monteiro AA2TX@amsat.org

2. Feb 15, 2010ARISSat-1 CDR2 Introduction Software that runs on the IHU to manage the available solar and battery power. Scope –Requirements –Design –Safety Considerations –Verification –Operations –Status

3. Feb 15, 2010ARISSat-1 CDR3 Requirements Run full satellite features as much as possible. Maintain enough battery power to keep the satellite running through eclipse. Minimize battery damage Extend satellite life as long as possible as battery end-of-life approaches.

4. Feb 15, 2010ARISSat-1 CDR4 Design Currently in progress… Measure satellite power consumption under various scenarios Characterize silver-zinc battery Characterize solar power system Devise suitable algorithm and SW Expected power modes: High, Low, Emergency

5. Feb 15, 2010ARISSat-1 CDR5 Safety Considerations none

6. Feb 15, 2010ARISSat-1 CDR6 Verification Test on Flat-Sat using solar panel and battery simulators Test with real (SMEX) solar panel Test with low-capacity Ag-Zn battery No opportunity to test with real battery

7. Feb 15, 2010ARISSat-1 CDR7 Operations At launch, satellite will operate in high power mode for at least 2 hours High power mode will be used as long as battery can support eclipse operation. As battery deteriorates, low power mode will be used alternately with high power mode. Near end of battery life, emergency power mode will be used to extend satellite operation as long as possible.

8. Feb 15, 2010ARISSat-1 CDR8 Status Measurements made on test battery Limited data available on test and real battery Solar panel simulator constructed Some power measurements made on “Flat-Sat” model MPPT problem detected – being worked Algorithm/SW under development