Power

The Power subsystem is responsible for providing sufficient electrical power to all components onboard the spacecraft that require power. Smallsats typically use solar cells to generate the power and batteries to store the power for use during eclipse periods. Determining how to configure the solar cells, battery packs, and their management is a crucial element of success for any spacecraft mission.

MR SAT will be equipped with 32 batteries and will have a 4S8P configuration to provide the optimal power efficiency. MR SAT will be docked to MRS SAT and will charge MRS SAT as well as the rest of the system until deployment when MR SAT’s batteries will be recharged by solar panels. According to power estimates, the batteries will last approximately five orbits, which is enough time to complete the two mission modes on MR SAT.

MRS SAT has four packs of Tenergy 7.4 V 3000 mAh Lithium polymer battery to power the boards and radio throughout the mission. These batteries will initially be charged through MR SAT while still docked, and must be fully charged before deployment will happen. Once deployed, MRS SAT will run until the batteries deplete at which point she will be unable to charge them.

M3 will be powered by primary (non-rechargeable) lithium carbon monofluoride magnesium oxide hybrid (Li/CFx-MnO2) cells for the duration of the mission. The cells being used have a shutdown separator. The nominal battery voltage will be 10.4 V. The EPS is designed to support a battery voltage range of 6–14 V. The EPS is designed to be powered externally during ground testing. No power sources besides the battery are present during flight.

Pictured above is the testing of M3’s voltage converter for the thruster which steps up

5 V to 3400 V.