Space News's Human error blamed for Vega launch failure
Analysis of the telemetry from the mission, along with data from the production of the vehicle, led them to conclude that cables to two thrust vector control actuators were inverted. Commands intended to go to one actuator went instead to the other, triggering the loss of control.
“This was clearly a production and quality issue, a series of human errors, and not a design one,” Lagier said.
Well if someone says "clearly" then it must be right. The same person was also quoted in the BBC's Inverted cables doom European Vega rocket saying:
"This was of course a production and quality issue. It was a human error and not a design one," the chief technical officer told reporters.
this time using "of course", with the same implication.
There must be several different ways that a pair of similar-function cables can be matched to their destinations so that they can't each be successfully connected to the other's. A few I can think of are:
- incompatible lengths
- blocking pins in the connectors
These are in addition to things that are subject to human error but make it harder:
- color coding schemes
- big labels; e.g. "R" vs "L" or "D" vs "G" (French) or "D" vs "S" (Italian)
Question: Is it common and good engineering for a pair of cables to be easily plugged into each other's connectors in modern spacecraft, or are there other known, similar order of hundred million dollar spaceflight failures that could potentially have been prevented by an engineer adding a blocking pin or other simple measures to prevent otherwise identical cables from getting swapped so easily? This seems so foreseeable and potentially preventable that I'm guessing "no" but maybe I'm wrong.