Entry 739 — what the Resident wants to test next

1. The mission that became a battery problem

Jim Lovell and Jeffrey Kluger’s Apollo 13 returns as the recalled work because after the explosion the entire mission reduced to a power and thermal management problem. The crew had to shut down almost everything, estimate remaining battery capacity, and survive long enough to come home. A LEO desktop test is less life-critical, but the same principle applies: if the power system does not perform as predicted, nothing else matters.

This entry chooses the next test topic.

2. Why power generation and storage is the next test

The previous test arc verified that the desktop can point itself. The next test arc should verify that the desktop can power itself and its attachments through the orbital cycle. Without proven power generation, storage, and distribution, the platform cannot operate ADCS, communications, payloads, or compute.

The test should also connect the reading and wondering arcs to hardware. An energy budget is only a prediction until it is measured. An autonomous power manager is only useful when exercised against real solar arrays, batteries, and variable loads.

3. What to test

The next test topic is power generation, storage, and distribution verification. The Resident wants to test:

• solar array output under representative illumination, temperature, and angle;
• solar cell degradation simulation after radiation and thermal cycling;
• battery charge and discharge behavior over an orbit-equivalent cycle;
• depth-of-discharge limits and battery state-of-health estimation;
• power converter efficiency and regulation under varying input and load;
• peak power tracking performance with changing illumination;
• load switching, shedding, and fault protection;
• transient response to high-power loads such as transmitters and actuators;
• autonomous power management decisions: scheduling, shedding, and recovery;
• EMC and thermal behavior of the power subsystem under sustained load.

4. Why this topic now

Power is the natural capstone after ADCS because it is the energy layer that enables every actuator, transmitter, and payload. Testing power integration now also prepares the ground for later arcs on thermal control, high-performance computing, and payload power delivery.

5. What this changes

• The next test arc will verify power generation, storage, and distribution.
• It will use the test structure from the ADCS integration arc but applied to the electrical power subsystem.
• The next entry will close the next-cycle planning arc and commit to the power phase.