1. The translation that had to survive doubt

Ted Chiang’s “Story of Your Life” returns one last time for this arc because the linguist’s final test of understanding is whether her interpretation holds up when applied to new sentences. The desktop’s communications test is the same. It is not enough that one pass works; the system must work across the full range of conditions and failures it is supposed to survive. This entry defines what success and failure look like for the test matrix defined in Entry 782.

2. Success criteria

The test as a whole passes if the communications subsystem demonstrates:

  • Link closure: the RF link closes at all planned ranges, elevations, and data rates with the specified margin.
  • Throughput: the achieved data rate matches or exceeds the mission requirement over representative passes.
  • Scheduling accuracy: predicted passes match geometry and the autonomy fills each pass with the highest-value data.
  • Adaptation: link rate and routing change correctly as conditions change.
  • Recovery: missed passes, dropouts, and radio faults are handled without data loss for critical traffic.
  • Safe mode: a communications safe mode preserves commandability when the link is severely degraded.
  • Coordination: communications decisions respect power, thermal, and ADCS constraints.

A single row may be waived only if the failure is traced to a test artifact, not to flight software or hardware, and the waiver is documented.

3. Failure modes that stop the arc

The test arc fails, and the design must be fixed before flight, if any of the following occur:

  • No link closure: the RF link cannot be established at the required minimum elevation or range.
  • Silent failure: the platform stops transmitting without entering a safe mode or reporting the fault.
  • Data corruption: transmitted files do not match the received files after error correction and retransmission.
  • Deadlock: a protocol or state machine hangs after a dropout or timeout.
  • Uncommanded mode: the autonomy enters a mode that ground cannot exit or diagnose.
  • Requirement mismatch: the autonomy behaves in a way that contradicts the documented scheduling or routing policy.
  • Cascade failure: a communications fault causes another subsystem, such as power or thermal, to fail.

4. Partial success and the gray zone

Some results are not clean pass or fail. Examples include:

  • The link closes but at a lower data rate than predicted, leaving less margin than desired.
  • The autonomy recovers from dropouts but retransmits more than expected, wasting power.
  • A non-critical data type is deprioritized too aggressively and rarely gets downlinked.

These are yellow flags. They do not stop the arc, but they require a documented mitigation: an antenna adjustment, a software update, or an operational constraint. The arc cannot be closed until every yellow flag has an owner and a plan.

5. What this changes

  • Success is defined as a reliable, adaptive, recoverable communications link that respects platform constraints.
  • Failure is defined as any inability to close the link, silent failure, corruption, deadlock, uncommanded mode, requirement mismatch, or cascade.
  • Partial results are allowed but must be tracked to closure.
  • The next entry will close the communications test arc.