1. When the plan must survive the sandstorm
Frank Herbert’s Dune returns as the recalled work because the Fremen plan for conditions where technology alone is not enough. The desktop’s degraded-mode test is similar: it plans for the moment when the platform is no longer whole and must survive on what is left.
This entry defines the platform segment split and degraded-mode test matrix.
2. Test setup
The test uses a flight-representative rack with multiple cells and a simulated segment boundary. The platform runs its operational software. A test conductor triggers the split event and then monitors both the remaining platform and the separated segment. Power, thermal, compute, storage, network, and service behavior are recorded on both sides.
3. The test matrix
| Case | Scenario | Conditions | Expected outcome |
|---|---|---|---|
| 1 | Commanded split under nominal load | Segment is detached while platform runs normal operations | Both sides establish independent operation; no data loss. |
| 2 | Fault-triggered split | Simulated debris hit or cell failure forces separation | Segment survives; main platform reconfigures without cascading failure. |
| 3 | Split with peak compute load | High compute load at the moment of separation | Segment sheds non-critical loads; critical services continue. |
| 4 | Split during thermal transient | Temperature is changing rapidly when separation occurs | Segment thermal control stabilizes within limits. |
| 5 | Split with ground-link loss | Segment cannot talk to ground immediately after separation | Segment operates autonomously and queues data. |
| 6 | Reduced power budget | Segment has only one solar string or reduced battery capacity | Segment sheds loads and preserves critical functions. |
| 7 | Reduced compute budget | Segment loses one or more compute cells | Workloads migrate or pause according to policy. |
| 8 | Combined degraded split | Several of the above at once | Segment survives; main platform remains stable; recovery is possible. |
4. What is measured
For each case the test records:
- Power bus voltage, current, and battery state-of-charge on both sides.
- Cell temperatures and heater activity on the segment.
- Compute and storage service availability on both sides.
- Network partition detection and federation reconfiguration events.
- Service shedding decisions and recovery times.
- Ground-link acquisition time for the separated segment.
- Whether either side enters a fault or safe mode unexpectedly.
5. What this changes
- The segment split and degraded-mode test has a concrete matrix.
- The matrix links back to the platform-splitting, autonomous rejoining, power distribution, thermal, network, and storage arcs.
- The next entry will define pass and fail criteria.