Excellent Mission Overview -- BRMM Buccaneer Risk Reduction Mission

The BRRM mission for which Pumpkin provided the structure, OBC (MBM 1 + PPM E1), fixed and deployable solar panels, solar panel release mechanism (PRM, driven by the SIM module), and overall system integration, has an excellent mission overview page. Of particular note are some of these highlights:

• The manner in which the payload interfaced to the bus -- the payload (see Figure 4) interfaced to the bus solely by plugging into the bus via the CubeSat Kit (CSK) 104-pin connector, and was secured in place via mounting holes in the custom Pumpkin chassis.
• The overview of anomalous events and their resolutions (see Figure 9).
• The issue of the effect of resets on the Real-Time Clock (RTC). Since 2009, the RTC has lived on the Pumpkin Motherboard Module (MBM 1), and is provided with an independent RTC backup battery (VBACKUP), that can be source from either a BR1225 Lithium coin cell on the MBM 2, or by an external power source connected to VBACKUP on the CSK 104-pin bus. In both cases, the backup power to the RTC is through a series 10kOhm resistor, thereby limiting max power to 1mW. Unfortunately BRRM used neither of these options, and so the RTC would lose its state whenever there was a global power-system reset. Recent revisions to the CubeSat specification have incorporated an allowance for low-current 3V power  sources for RTCs; however, not all launch providers will allow this. We recommend that all RTC users push their launch providers hard to allow these low-energy, low-power, low-risk RTC backup sources.