The accident of the Luna-25 station occurred due to abnormal functioning of the onboard control complex (BCU). This conclusion was reached by the interdepartmental commission, the results of its work published On the official website of Roscosmos.
The BKU operated abnormally due to the fact that the accelerometer unit (unit for measuring angular velocities) in the BIUS-L device did not turn on due to the possible entry into a data array of commands with different priorities for execution by the device. In this case, the distribution of commands in the data arrays is random (probabilistic) in nature.
“In this regard, the onboard control complex received a zero signal from the accelerometer unit of the BIUS-L device. This, when delivering a corrective pulse, did not allow recording the moment when the required speed was achieved and timely shutdown of the spacecraft propulsion system, as a result of which its shutdown occurred according to a temporary setting. [команде]”, says the message from Roscosmos.
While the vehicle was transferred from circular lunar orbit to the elliptical pre-landing propulsion system, it operated for 127 seconds instead of the planned 84 seconds.
“As a result, the station moved into an open orbit for which it was not designed and collided with the lunar surface,” Roscosmos said.
To ensure that the next month’s mission would not end in failure, the commission “formulated recommendations for additional activities.”
16 versions of the disaster were checked
Previously, the Luna-25 accident was explained by Roscosmos CEO Yuri Borisov as the accelerometer not turning on.
“We have 16 versions, we have already checked 11” – reported It was at a press conference in mid-September.
25 August Borisov statedAfter the Luna-25 accident, Russia is considering the possibility of repeating the mission to land an automatic station at the South Pole of the Moon in 2025-2026. According to him, Russian designers and scientists “are burning with the idea of continuing the Moon project.”
“Under no circumstances should you interrupt the lunar program; that would be the worst decision.” aforementioned Borisov in an interview with the Rossiya-24 TV channel.
Borisov reported that the launch of the Luna-26 mission is planned for 2027, the launch of the Luna-27 – 2028, and the launch of the Luna-28 mission is planned for 2030 or later.
First flight since 1976
The first lunar mission in modern Russian history was launched on August 11 (the previous station, the Soviet Luna-24, was launched in 1976). The launch of Luna-25 was carried out from the Vostochny cosmodrome (Amur region) using the Soyuz-2.1b launch vehicle with the Fregat upper stage.
Luna-25 was supposed to analyze the soil of the Earth’s natural satellite and conduct long-term scientific research. Including the study of the upper layer of the surface in the south polar region, the influence of the solar wind on the cosmic body, as well as the study of the lunar exosphere (outer part of the upper atmosphere).
The station entered orbit of the Moon, the first images were taken from it, one of the devices recorded the impact of a micrometeorite on the surface of Luna-25.
As expected, the station will land on the Moon on August 21, but on August 19 the station will land on the Moon. collapsed About the lunar surface.