2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
The Commission for Investigation of the Soyuz-FG rocket accident today announced that the cause of the accident was damage to one of the rocket's sensors, and it was damaged already during the assembly of the rocket at the cosmodrome. What the results of the investigation mean and how long will the Russian cosmonautics recover from it, says space and military journalist Mikhail Kotov.
Today, November 1, 2018, a press conference was held, at which the results of the investigation into the accident at the launch of the Soyuz-FG launch vehicle with the Soyuz MS-10 manned transport vehicle were published. As the state commission established, the cause of the accident was the abnormal operation of one of the side accelerators. During the separation, he struck the second stage of the rocket. The accelerator itself could not separate normally, because the cover of the withdrawal nozzle did not open, and this, in turn, did not happen due to the deformation of the rod of the separation contact sensor.
What happened?
To understand the intricacies of the bureaucratic and technical language of the state commission, let's start from the very beginning. The Soyuz-FG rocket has three stages. The first stage consists of four conical boosters attached to the main rocket block, most of which is the second stage. The third step is located above the second, the place of their separation can be determined by the openwork structure of the transitional truss.
Rescue system operation during an accident.
The second and first stages work together, but in the first, the fuel and oxidizer run out earlier, therefore, approximately at the end of the second minute of the flight, the first stage - side boosters - is dropped. First, the lower connections of the side blocks are broken, and due to their own thrust, the lower parts of the side boosters begin to separate from the rocket. After the lower part leaves a sufficient distance, the oxidizer tank valves are first opened to give the blocks additional movement, and then the fuel tank valve is opened, and it finally - due to the jet thrust - throws the blocks away from the launch vehicle.
Video frame from the rocket: the moment before turning off the engines and separating the side blocks.
The side blocks are separated, it is clear that the "D" block (in the picture on the left) is lagging behind.
The side blocks detached, but the "D" block got stuck in place, after a while it will hit the central block.
In this case, the malfunction occurred at the stage of opening the oxidizer tank - for one of the blocks (block "D") it simply did not work. The block remained in the mount, it was twisted and hit against the second stage fuel tank, which provoked the accident. The emergency rescue system, its second part (the first - the boom at the very top of the rocket - had already been separated by that time), with the help of the withdrawal engines located on the nose fairing, transferred the spacecraft to the ballistic trajectory landing mode. Then you all know.
Who's guilty?
Judging by the information published by the commission, the assembly team is to blame for assembling the rocket in the assembly and test building (MIC) of the Baikonur cosmodrome. It was there that a breakdown occurred during the assembly of the rocket. According to the commission, the installers damaged the split contact sensor stem during assembly by bending it six and a half degrees.
Under the round red cap is the oxidizer tank valve, which opens at the command of the sensor when the stages are separated.
There is only one assembly team that connects the Soyuz launch vehicles and the payload into one whole. It is she who travels to different cosmodromes, collecting rockets from pre-prepared packages. Now we will have to disassemble and recheck two ready-made rockets, one at the Kourou Cosmodrome in French Guiana (payload - MetOp-C satellite), and the second at Baikonur (payload - Progress cargo ship).
Good and bad
In fact, for the Russian cosmonautics, what happened is one of the most “successful”, if this word is applicable, options. It would be much worse if the marriage was more serious, admitted during production and would require a complete recheck of all packages of ready-made Soyuz launch vehicles. This could severely slow down all launches and move the already planned launches, jeopardizing the work of the crews on the International Space Station.
Checking and reassembling the finished packages could take several months. Now it will be possible to close the gap quickly enough. The error can be corrected, it is unlikely that it will arise again, and this facilitates the further work of Roscosmos.
What could happen if the commission found out that the defect appeared at the production stage? This can be understood if we recall the events of 2016-2017. Then, after the accident of the Progress MS-04 cargo spacecraft, which occurred on December 1, 2016, on the Soyuz-FG and Soyuz-U launch vehicles designed to launch the Soyuz MS-04 manned spacecraft and the Soyuz MS-04 cargo spacecraft Progress MS-05”, the RD-0110 engines produced by the Voronezh Mechanical Plant had to be changed.
Further - more: it turned out that when assembling the engines at the plant, they used a less heat-resistant solder than is required by the regulations. After that, Roskosmos recalled to the Voronezh Mechanical Plant all the second and third stage engines of all ready-made Proton-M launch vehicles. As a result, the interruption in launches was several months, and the postponement affected the commercial launches of Roscosmos.
In the current situation, it remains only to convince insurance companies that this is an accident, to persuade them not to raise insurance premiums strongly, and then we can assume that the accident that happened was survived with little blood. The astronauts are alive and well, the problem has been found and eliminated, the flights will continue soon, you can breathe out. However, wait and see.
