Russia says a software glitch caused the Nauka module to launch thrusters after docking at the International Space Station

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The Nauka module (left) is docked with the International Space Station, with the Soyuz spacecraft (right) parked nearby. Photo: Roscosmos

Russian cosmonauts aboard the International Space Station continue to solve a problem that caused a newly arrived Nauka module to inadvertently fire thrusters after docking at the orbital position.

The situation now seems to be under control, but for 47 minutes yesterday, things got a little weird and even scary.

At about 12:34 p.m. EDT, about three hours after docking with the International Space Station, the newly arrived Multipurpose Laboratory Module (MLM), or Nauka, began firing its thrusters. As a result of this unexpected thrust, the station lost control of the situation, causing it to drift at a rate of about half a degree per second, International Space Station Program Director Joel Montalbano explained at a NASA press conference yesterday. In total, the sudden boost caused the space station to shift by about 45 degrees, mostly in pitch.

Russian flight controllers reacted by turning off the Nauka engines. Then the bombers on the Zvezda unit and the cargo ship Progress moored returned the space station to normal. The situation was regained at 1:29 p.m. EDT, according to NASA.

“This is one of the most serious accidents in the 24 years of the International Space Station’s history.”

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“At the moment, the station is in its normal orientation, and all the systems of the ISS and the systems of the multi-purpose laboratory modules are operating normally,” Vladimir Solovyov, flight director of the Russian section of the International Space Station, explained in the Roscosmos statement. “A reliable internal power and command interface was established, as well as a power supply interface that connected the unit to the station.”

NASA said the crew of Flight 65 of the International Space Station was never in danger, and there were no reports of damage. Montalbano said he was “not too concerned” about the incident, saying that mission monitors are well trained for such situations. He added that repetition was no longer possible, saying that the Nauka engines were “prevented” by Russian observers.

“This is one of the most dangerous accidents in the ISS’s 24-year history,” Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, wrote to me in an email. “Losing control of the situation in principle risks the disintegration of the complex.”

McDowell referred to an incident in 2016 in which the Japanese satellite Hitomi, after experiencing problems with the attitude control system, went into an uncontrollable rotation, causing it to disintegrate. McDowell said the situation on the ISS “wasn’t extreme,” and the ISS “maybe ‘nowhere near experiencing any structural failures, but you don’t want a 400-tonne station with large flexible parts like solar arrays falling off end on end.'”

McDowell said he is concerned about the state of some of the outside experiences associated only with wire ties. The ‘battle’ between the Nauka and other control modules – where multiple sets of thrusters were involved – could have created ‘oscillations in flexible parts of the structure, particularly ‘radiators and solar arrays’, where the design tolerance might have been exceeded.

Solovyov said that a “short-term program malfunction” was to blame for the accident, since “a direct command was mistakenly executed to start the unit’s engines in order to pull out, which led to some modification in the direction of the complex as a whole.”

As a result of this unintended launch, NASA has postponed today’s scheduled launch of an unmanned Boeing CST-100 Starliner commercial crew vehicle. The second test of this car is now scheduled for August 3 at 1:20 PM EST. According to a NASA statement, the postponement “allows the ISS team time to continue the egress operations of the newly arrived Nauka module from Roscosmos and to ensure that the station is ready for Starliner arrival.” Sending an experimental spacecraft to the International Space Station while the crew continues to resolve a dangerous situation certainly wouldn’t make much sense.

Mission specialists are now trying to determine how much fuel the ISS lost as the crew had to regain control of the situation. Montalbano said the measure did not deplete the station’s fuel reserves, but it “was obviously more impulse than we wanted but nothing to worry me.”

Russian cosmonauts are now working through a set of measures to ensure the “unconditional safety” of the International Space Station and its crew, specifically tasks related to the Nauka module’s propulsion system, according to a Roscosmos statement. After this is done, the crew will open the gates, first the Zvezda service unit and then the new Russian unit. Solovyov said that the cosmonauts “will open the hatches, enter the unit, turn on the necessary means for purification of the atmosphere and begin normal normal work.” They will also have to equalize the pressure in the Nauka unit, which will take some time, as the unit’s total volume includes 2,472 cubic feet (70 cubic metres).

The Nauka unit was launched from the Baikonur Cosmodrome on July 21, but the initial engine burnout failed, forcing flight controllers to use spare engines. Concerns about the wonky antenna and docking port complicated matters even further, but the unit “nominally” docked to the International Space Station on July 29 at 9:29 AM EDT.

The new unit will provide additional space for experiments, cargo storage, and accommodate new water and oxygen replenishment equipment. The Nauka has a second restroom for the Russian crew and an additional room for a third member of the Russian crew. The unit also delivered the new airlock and the new European robotic arm (ERA), which will be the first robotic arm to serve the Russian sector.

MORE: An inspector-like robotic arm heads toward the International Space Station.

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