Russian investigators pin down cause of Luna-25 failure
Though the investigation is not yet complete, reports out of Russia indicate that the cause of the failure of Luna-25 during an engine burn while in orbit around the Moon has been identified.
The article at the link provides the details, which involve problems with two “BIUS-L accelerometers” during the flight, which for reasons not yet understood were switching from the primary to the secondary randomly during the journey to the Moon, apparently because of some failure.
However, ahead of the fateful lunar orbit correction on August 19, both accelerometers worked correctly, but once the maneuver started, one set failed again, while the flight control system never switched to data from the second set. As a result, onboard computers were not receiving data about critical parameters required for properly completing the orbit correction, such as orientation of the spacecraft in space, velocity and altitude.
If confirmed, this crash scenario would likely implicate deficiencies in the development or testing of the flight control system and its software rather than any mechanical problem of the propulsion system, which was implied in the initial statement about the incident. [emphasis mine]
The highlighted sentence says it all. The serious quality control problems that have hampered Russia’s space efforts remain, and in fact appear systemic throughout its entire aerospace industry. In fact, this failure of a planetary probe helps explain the many difficulties Russia has been having in its war in the Ukraine, attributable to these same issues.
Though the investigation is not yet complete, reports out of Russia indicate that the cause of the failure of Luna-25 during an engine burn while in orbit around the Moon has been identified.
The article at the link provides the details, which involve problems with two “BIUS-L accelerometers” during the flight, which for reasons not yet understood were switching from the primary to the secondary randomly during the journey to the Moon, apparently because of some failure.
However, ahead of the fateful lunar orbit correction on August 19, both accelerometers worked correctly, but once the maneuver started, one set failed again, while the flight control system never switched to data from the second set. As a result, onboard computers were not receiving data about critical parameters required for properly completing the orbit correction, such as orientation of the spacecraft in space, velocity and altitude.
If confirmed, this crash scenario would likely implicate deficiencies in the development or testing of the flight control system and its software rather than any mechanical problem of the propulsion system, which was implied in the initial statement about the incident. [emphasis mine]
The highlighted sentence says it all. The serious quality control problems that have hampered Russia’s space efforts remain, and in fact appear systemic throughout its entire aerospace industry. In fact, this failure of a planetary probe helps explain the many difficulties Russia has been having in its war in the Ukraine, attributable to these same issues.
