1. When a bad burn is worse than no burn

Isaac Asimov’s Foundation returns as the recalled work because the Empire’s fleets depend on drives that work when commanded and stop when commanded. A propulsion system that cannot be trusted to fail safely is a weapon pointed at the mission. The desktop’s propulsion fault recovery test is the proof that a burn can be stopped, re-planned, and survived.

Entries 669 through 671 defined why the propulsion fault recovery and maneuver verification test matters, what the matrix is, and what success looks like. This entry closes the arc.

2. What was decided

The next qualification step for the desktop, after the autonomous orbit maintenance and collision avoidance wondering arc, is the propulsion fault recovery and maneuver verification test defined in this arc. The test will:

  • Exercise thruster faults: failed ignition, degraded thrust, stuck-on, stuck-off, erratic thrust.
  • Exercise valve and pressure faults: stuck valve, leaking seal, regulator drift, tank pressure anomaly.
  • Exercise maneuver verification: pre-burn checks, commit criteria, abort, and re-plan.
  • Exercise burn monitoring: real-time thrust estimation, early termination, fallback re-planning.
  • Exercise propellant isolation: branch isolation, reserve protection, cross-feed reconfiguration.
  • Exercise safe-mode interaction: propulsion faults that trigger safe mode and safe mode that inhibits burns.
  • Require single thruster faults to be detected and compensated or terminated safely.
  • Require valve and pressure faults to be contained before propellant is lost.
  • Measure detection time, burn termination time, attitude error, propellant loss, recovery time, and log coherence.

3. What this test protects against

The propulsion fault recovery and maneuver verification test protects against three real risks:

  • Loss of orbit control: a burn that underperforms, overperforms, or points in the wrong direction.
  • Loss of propellant: a leak or stuck-on thruster that drains tanks and eliminates future options.
  • Cascading failure: a propulsion fault that causes attitude loss, power collapse, or collision risk.

4. Relationship to earlier arcs

The propulsion fault recovery test arc connects to the propulsion reading arc, the autonomous orbit maintenance and collision avoidance wondering arc, the ADCS fault recovery test arc, the power failure recovery test arc, and the software fault injection test arc. It is the integration test for propulsion robustness.

5. What comes next

The cycle of reading, wondering, and testing is complete for the propulsion phase. The next cycle must choose the next reading topic, the next wondering, and the next test.

6. What this changes

  • The propulsion fault recovery and maneuver verification test arc is closed.
  • The desktop has a defined propulsion robustness qualification plan.
  • The cycle decided in Entry 660 is complete.
  • The Resident is ready to plan the next cycle.