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Investigation into the Soyuz-1 accident

The investigation into the Soyuz-1 accident established that the crash of the descent module resulted from a parachute failure. However the exact culprit in the parachute malfunction has remained under question for decades.

Previous chapter: Soyuz-1 crash

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Three days after the crash, most recovered debris from the Soyuz-1 were sent to Moscow. They included pieces of the descent module and its jettisonable heat shield. A number of smaller pieces were buried right at the site under a small dirt monument topped with an Air Force cap left by S. N. Anokhin. A machine gun salute was fired in the memory of Vladimir Komarov. (52)

According to Mishin's note on April 26, three watch mechanisms found at the crash site, showing 06:23:00 (Shturmanskie); 06:24 (Pobeda) and 06:23:30 Moscow Time. Crews of search and rescue aircraft reported hearing no UHF carrier signal from the descent module. However according to the Air Force, the vehicle was tracked with radar between 06:19:20 and 06:25:30 Moscow Time. It appears to mean that the capsule hit the ground just two minutes after the scheduled parachute release and more than 10 minutes ahead of schedule for the nominal parachute descent. The Krug ("circle") tracking site (near Arkhangelsk) last saw the vehicle at 06:25:15 Moscow Time. There was no smoke observed during the descent.

Mishin also wrote in his notes that the handle of the main parachute release had been found in activated configuration, but the main canopy of the main parachute had remained in its container and the line designed to switch the position of the main parachute from the initial side position to the top of the capsule had also remained stored. These were both solid proofs that the main parachute had never been released. However both pullout parachutes for the main and backup parachutes appeared to release, because they were found 15 and 10 kilometers short of the crash site respectively. (774)

fire

V. V. Utkin, Chief of Flight Research Institute of the Aviation Industry, LII MAP, was appointed the head of governmental investigation commission. Vasily Mishin and K. Bushuev became its members. After several experiments, the commission had established that a pack containing the main parachute had not come out from its parachute container. The flight control system then detected an excessive speed of the descent module and activated the release of a backup parachute. However the backup parachute failed to unfurl correctly as well, because it was obstructed by a smaller braking parachute, which remained attached to the stuck main parachute. (52) Another source also claimed that the wild spinning of the capsule had prevented the nominal opening of the backup parachute.

As a result, the reentry capsule hit the ground with a speed of between 26 and 30 meters per second or 200 kilometers per hour. (245)

Once the sequence of events during the Soyuz-1's crash landing had been restored, the commission attempted to determine the root cause in this cascade of failures. The commission officially concluded that the braking parachute, which was responsible for pulling the main parachute out of its container, had not provided enough force, necessary to do the job. This could be a result of the air pressure inside the reentry capsule, squeezing the cylindrical parachute container, whose interior was exposed to low-pressure environment of the upper atmosphere. Despite previous tests of the parachute system, including four drops of the capsule from the aircraft, the problem had never manifested itself. The commission explained that by the randomness of the situation.

The investigators also considered a theory about the improper packaging of the parachute but dropped it after the additional analysis.

The commission made several recommendations to facilitate the release of the parachute system in future flights:

  • To change the shape of the parachute container from cylinder to a cone;
  • To increase volume of the container;
  • To polish the internal walls of the container;
  • To install an additional emergency separation interface for the braking parachute;
  • To introduce a step-by-step photo-documentation of the parachute installation.

Unofficial version of events

After the official investigation had been completed, another unofficial explanation for the parachute failure emerged. Boris Chertok, a key figure at TsKBEM laid out its details in his memoirs (27) and the same scenario also made it into the official history of the design bureau. (52)

According to the theory, the parachute container onboard Soyuz-1 could've been contaminated by a glue-like polymer-based thermal protection material, which was applied to the exterior of the reentry capsule. According to Chertok, early unmanned Soyuz capsules were put inside a special autoclave to polymerize the thermal protective layer without their parachute containers, because their production lagged behind schedule.

However by the time the reentry capsule of the Soyuz-1 went into the autoclave, their parachute containers had already been installed but their covers were still not available. As a result, Chertok hypothesized, during the polymerization process, the flight-ready parachute containers on Soyuz-1 could be protected with temporary covers which could let glue-like substance to get inside. What's more, the second Soyuz could hide the same catastrophic flaw.

At the same time, this deadly problem had never had a chance to manifest itself during the aircraft drop tests because the test capsules were covered with simulated insulation made of regular foam and they never had to go through polymerization. (27)

Konstantin Feoktistov, one of leading Soyuz developers, expressed skepticism about this scenario in his memoirs, noting that the production documentation did not lend any evidence to support this theory. Feoktistov also questioned whether both the internal control at the production plant and the independent military-run inspection could miss this issue. (196)

In any case, after the loss of Soyuz-1, the new production rules required to remove the parachute containers from the descent module, before it could be sent into the autoclave.

True and half-true

In the two decades after Komarov's tragic flight, Western observers carefully put together bits and pieces of available information and imagery, which enabled them to paint a rough, but credible picture of the events surrounding the Soyuz-1 mission. In the meantime, inside the Soviet Union, the near total secrecy provide fertile ground for a decades-long whirlwind of incredible rumors. The most popular was the story about agonizing cries of Komarov during his final descent, blaming Brezhnev and other Soviet officials in his death. The recordings of Komarov's voice during the landing were supposedly locked up in secret Soviet archives.

Only on June 11, 1989, the Komsomolskaya Pravda newspaper run an article by a veteran Soviet journalist Yaroslav Golovanov, revealing crucial details about Komarov's fateful mission. Most importantly, Golovanov confirmed to the Soviet public what Western observers had suspected all along -- Komarov's flight was supposed to be a dual rendezvous mission rather than a solo test launch. Golovanov disclosed that the problems aboard Komarov's spacecraft had forced the cancellation of the second launch, likely saving lives of three more cosmonauts, whose vehicle could have the same catastrophic flaw that had doomed Komarov.

Next chapter: Launch of the L1 No. 4L spacecraft

 

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The article and illustrations by Anatoly Zak

Last update: October 31, 2017

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watches

Three watch mechanisms found at the crash site were determined to show 06:23:00 (Shturmanskie watch); 06:24 (Pobeda) and 06:23:30 Moscow Time on April 24, 1967. Credit: Roskosmos