Motor Startup Failure

published Last Updated: Oct 12, 2026 HW: all

motor-startup-failure motor startup failure

Background

Healthy propulsion motors occasionally fail to start up. These are probabilistic firmware failures not necessarily indicative of hardware damage. A motor may have to start up many times in a single mission. A validator tracks the time it takes for it to startup in each instance. If it never starts up, that validator’s metric would read -1 for that instance.

Troubleshooting Steps

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Check validator results for this flight from the P2F validator results page. If the startup metric does not exist in P2F, check the same metric in the P2M validator results page for the mission. Use P2M only as a fallback when the metric is unavailable in P2F.

In the validator results, find the startup metrics for the affected hover motor: propulsion_motor_startup/{motor}_torque_control_startup_time_s_occurrence_{n}, where {motor} is hover_port_aft, hover_stbd_aft, hover_port_fwd, or hover_stbd_fwd. There may be multiple occurrences. Check only the last occurrence—the metric with the highest numeric value of {n}.

The validator is in the Zip A, Firmware_zip_a_ev2_experimental space.

Does the validator value read -1?

Yes, the value is -1No, the value is not -1The startup metric is missing or unavailable

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Topic history

1. 2026-10-09 qingyuan.cao
   Update motor startup validator lookup guidance
   Commit 7c5f469
2. 2026-10-07 Susan Minne Bulk/mechanical change
   Replace individual guide ownership with system technical contacts
   Commit dca5a1a

Baseline import

Initial import into service_docs

Imported by Anthony Berbari on 2026-09-29

FSW-63448: Distinguish stalls and preflight failures in service docs

Commit 9cac270

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