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"Black Box"


Unexplained hole aboard Soyuz puzzles crew, stirs up wild theories

Stories abound on the origin of a drill hole aboard the Soyuz MS-09 spacecraft parked at the International Space Station. The small breach was quickly isolated after its discovery on August 29, but its origin still remains a mystery.

Previous chapter: Soyuz MS-09 mission


On August 29, a slow air leak aboard the International Space Station, ISS, caused some pressure drop inside the outpost and was eventually isolated to a small hole in the Soyuz MS-09 spacecraft docked at the orbital lab.

According to NASA, on August 29, 2018, mission control in Houston noticed a pressure drop aboard the International Space Station. On the morning of August 30, NASA issued a following statement:

About 7 p.m. EDT Wednesday (August 29), International Space Station flight controllers in Houston and Moscow began seeing signs of a minute pressure leak in the complex.

As flight controllers monitored their data, the decision was made to allow the Expedition 56 crew to sleep since they were in no danger. When the crew was awakened at its normal hour this morning, flight controllers at Mission Control in Houston and at the Russian Mission Control Center outside Moscow began working procedures to try to determine the location of the leak.

The six crew members, station Commander Drew Feustel, Flight Engineers Ricky Arnold and Serena Auñón-Chancellor of NASA, Alexander Gerst of ESA (European Space Agency) and Oleg Artemyev and Sergey Prokopiev of the Russian space agency Roskosmos, gathered in the Russian segment of the station and, after extensive checks, reported that the leak appears to be on the Russian side of the orbital outpost.

Program officials and flight controllers are continuing to monitor the situation as the crew works through its troubleshooting procedures, NASA said.

According to Russian sources, the problem was found in the Habitation Module of the Soyuz MS-09 spacecraft, where the crew detected two small cracks, reaching 1.5 millimeters in size. According to mission control in Houston, the small leak was varying around 0.6 millimeters on mercury table per hour (0.8 millibars per hour). Alexander Gerst first discovered the leak on the wall behind the toilet unit and used his finger to initially plug it. (According to US sources, the second hole was found to be internal and not breaching the hull, while Russian sources later reported the existence of only one crack.)


The cosmonauts photographed the affected area and sent it to mission control for analysis. The first estimates indicated that the breach could have been caused by a meteor or debris strikes which had punctured the hull of the spacecraft. Head of the Roskosmos State Corporation Dmitry Rogozin confirmed the incident but said that the problem had been resolved. According to Rogozin, the crew had to close off various sections of the station to isolate the leak.

According to ESA sources, the area of the leak was temporarily sealed with Kapton tape, while Russian cosmonauts were working on a permanent sealing patch using a special repair kit with epoxy-saturated gauze. There were apparently some disagreement between the US commander of the station Drew Feustel and Russian crew members about the need to first test the repair techniques on the ground, but, the cosmonauts ultimately decided to apply the patch as soon as possible on the advice from mission control in Korolev.

The second slightly larger patch was apparently added later, according to publicly available communications between the ISS crew and mission control. Some bulging was reported on the patch, apparently as a result of an air bubble in the glue. Checks with ultrasound reportedly showed that the leak had stopped.

It was later reported that mission control had noticed first signs of drop in pressure around August 28, but because the rate of leak had been below the accepted 0.5 mmHg limit, the crew had not been alerted. Only when the leak reached 0.8 mmHg, mission controllers informed the crew.


After some drop during the night from August 29 to August 30, the air pressure inside the ISS was brought to normal and was reported as stable at sea level. In the meantime, mission control informed the crew that all scheduled activities for August 30 had been cancelled.

On August 31, Roskosmos announced that the monitoring conducted throughout the night from August 30 had shown no pressure changes inside the spacecraft. Rogozin also informed journalists that the Soyuz MS-09 spacecraft could be used for safe return to Earth.

The investigators initially considered an external impact on the spacecraft, as well as structural failure, such as metal fatigue, as possible culprits in the breach. However, the visual appearance of the hole looked like it could have been left by a mechanical drill, possibly during the manufacturing process on the ground.

On September 3, Russian media confirmed the on-the-ground origin of the hole, citing two industry sources. According to these reports, a person responsible for the production defect had been also located. Whoever drilled that hole apparently realized the mistake during the production and patched it with glue. (Interestingly, there were no visible glue traces in the available photos of the hole). As a result, the breach was not detected during the leak checks of the vehicle on the ground and had not manifested itself in the first two months in orbit. However, the glue eventually dried up and was pushed out (by internal pressure), according to this scenario.

During a meeting of the investigation commission on September 3, RKK Energia made a decision to initiate an inspection of all Soyuz MS and Progress MS spacecraft undergoing assembly at the company's factory in Korolev near Moscow within a few days. The vehicles awaiting launch at Baikonur Cosmodrome in Kazakhstan, were also scheduled to be re-checked beginning the following week. More than 10 ships in various stages of production would have to be inspected, RIA Novosti reported.

On September 4, the Head of Roskosmos Dmitry Rogozin reconfirmed the fact that the two holes in the Soyuz had been made with a drill. According to Rogozin, the the drilling was "amateurish" because, the drill was "sliding" on the hull of the spacecraft.

"We are checking the "ground-based" (origin) scenario," Rogozin was quoted as saying, "However we are not discounting an intentional impact in space. There are several drill engagement attempts there... There is a clear impact on the hull from the inside."

Rogozin said that RKK Energia would have to find the person who had made the hole and determine whether it was a production defect or an intentional action.

As of September 4, the investigation was scheduled to be wrapped up in the middle of the month, Roskosmos said.

Russians investigate possible sabotage behind the Soyuz air leak


Sergei Prokopiev shows a patched hole inside the Habiation Module of the Soyuz MS-09 spacecraft.

The accident with a drill hole discovered aboard Soyuz made a bizarre turn around September 6. By that time, the Russian investigators had reportedly all but ruled out the ground-based origin of the drill hole. This conclusion was reportedly made after the review of the processing documentation, interviews with the Soyuz assembly personnel and it was based on photos delivered by the Russian cosmonauts. In particular, the attention of investigators was attracted by multiple scratches around the hole, indicating several unsuccessful attempts to engage the drill bit, which seemed to be typical of work in weightlessness. As many as eight attempts were apparently made, before the drill had finally penetrated the hull.

At the same time, the investigators reportedly cleared of their suspicions a former worker at RKK Energia who participated in the production of the Soyuz MS-09.

Instead, Russian investigators re-focused on the actions of the ISS crew, particularly NASA astronauts. Because the natural origin of the hole, such as impact by meteoroids or by space junk, was long out of the question, the officials decided to investigate very improbable sabotage scenarios.

The easiest explanation under such circumstances would be a mental health issue that could cause one of the crew members to commit such a nearly suicidal act. Roskosmos reportedly even requested NASA to provide information on the mental health of its current crew members aboard the ISS. NASA apparently refused citing medical privacy concerns, only fueling further Russian suspicions.

On September 11, the Head of Roskosmos Dmitry Rogozin also told reporters that security services had already been involved into the investigation. He also admitted that the situation had turned out to be much more complicated than previously thought and he announced that the State Corporation had formed its own investigative commission to look into the incident.

Internally, Russians also wondered whether their recent disputes with NASA over certification of newly developed US spacecraft for upcoming flights with astronauts and cosmonauts onboard, could trigger a "backlash" from the Americans aimed to undermine the Soyuz, Russian industry sources told (The American vehicles would end the monopoly of the Soyuz in bringing crews to the station.) On September 12, the Moscow-based Kommersant daily quoted another improbable theory originating from the Russian investigation circles. According to that story, the motive for the drilling of the hole by the astronauts was to trigger the urgent return to Earth of the Soyuz MS-09 spacecraft due to some hidden medical problems with one of the astronauts, which the Americans wanted to camouflage behind the accident. The culprit behind the leak would never be found, if the crew left the station in emergency, the proponents of that hypothesis said.

As of an opportunity for the US crew to drill in the Soyuz, Russian officials claimed that the astronauts could have access to the spacecraft in August, when the two Russian cosmonauts were performing a spacewalk. The US crew members had an electric drill onboard, the Russian sources said. The Russians were also suspicious that the leak had first been detected by the US crew members during a sleep period.

To test these fantastic theories, the Russian investigators discussed preserving and bringing back to Earth air filters aboard the Russian Segment of the station. The filters could potentially capture micro debris from the drilling, if it had been performed in orbit, Russian industry sources told

The Russian suspicions were serious enough for the US commander of the station Drew Feustel to publicly deny them in an interview with ABC News.


On September 10, the Russian cosmonaut Sergei Prokopiev, from the Soyuz MS-09 crew, reported from the ISS that the whole international crew had excellent relations and was working in cooperative friendly spirit. Prokopiev also provided a video tour of the Habitation Module in the Soyuz with the patched up hole.

The story was also fiercely debated in the Russian press and on the Russian-language Internet. The authors of the sabotage scenarios were themselves quickly suspected of an attempt to shift the blame elsewhere from the beleaguered Russian space industry. The incident also gave rise to a whole plethora of Internet folklore, including numerous jokes, memes and even a couple of humorous poems in Russian language...

Russian officials back "production defect" theory in the Soyuz accident

On September 11, Sergei Saveliev, Deputy Director General at Roskosmos, announced that the State Corporation would inform all its partners on the results of the investigation into the Soyuz leak and would seek other agencies' endorsement of the Russian conclusions.

The next day, Deputy Prime Minister Yuri Borisov, who was appointed in May to oversee the rocket industry, said that it would be absolutely unacceptable to drop even a shadow of an accusation either on cosmonauts or astronauts while the investigation was in progress. "It is not excluded that the culprit is in a production defect (and) many theories can be drawn up," Borisov was quoted as saying by the official Russian media, "The fact remains, the pressure began falling after several months of the ship's presence in orbit. The hole is very small, it is good that it was noticed in time and taken care of."

According to Borisov, the ISS crew is a united collective where there are no political disagreements. "Today, before the conclusion of the investigation, hanging labels and doing a witch hunt is, mildly speaking, shortsighted and dangerous," Borisov said.

Borisov's statement also coincided with the report that early simulations performed on the ground by investigators at the spacecraft manufacturer, RKK Energia, showed a need for a half-a-meter-long drill in order to make a hole inside the cramped compartment under the required angle. However, the same hole could be easily made inside the unfurnished Habitation Module during its assembly, industry sources said quoted by RIA Novosti.

Next chapter: Plans for a spacewalk to investigate Soyuz MS-09 hole mystery (INSIDER CONTENT)


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This page is maintained by Anatoly Zak; Last update: December 12, 2018

Page editor: Alain Chabot; Last edit: September 14, 2018

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The patched hole inside the Habiation Module of the Soyuz MS-09 spacecraft. Click to enlarge. Credit: Roskosmos