Russia says ‘software failure’ caused thruster misfire at space station

Yesterday’s unexpected tilting of the International Space Station was caused by a software glitch, according to Russian space agency Roscosmos.

A new Russian module dubbed Nauka arrived at the space station Thursday morning (July 29). In development for more than a decade, Nauka is designed to host science experiments, anchor visiting vehicles and serve as a gateway for spacewalks. However, while the module’s arrival appeared to go smoothly, about three hours after docking, the module unexpectedly began firing its thrusters in an incident that caused the space station to tilt from its typical position for about 45 minutes in what engineers call a “loss of attitude control.”

“Due to a short-term software failure, a direct command was mistakenly implemented to turn on the module’s engines for withdrawal, which led to some modification of the orientation of the complex as a whole,” Roscosmos officials wrote in a statement published on Friday (July 30).

Related: Russia’s Nauka module briefly tilts space station with unplanned thruster fire

“At the moment, the station is in its normal orientation, all the ISS [International Space Station] and the multipurpose laboratory module [Nauka] systems are operating normally,” Roscomsos officials noted. “The crew is now busy balancing the pressure in the Nauka module. This is a rather lengthy procedure, because the total volume of the module is about 70 cubic meters. In the afternoon, the crew will open the hatches, enter the module, turn on the necessary means of purifying the atmosphere and begin normal regular work.”

Currently, cosmonauts Oleg Novitsky and Pyotr Dubrov represent Russia on the orbiting laboratory. The pair was in the process of preparing to open the paired hatches between Nauka and the rest of the station yesterday when the module’s thrusters began to fire, pushing and tilting the space station until thrusters on the Russian Zvedza service module and the Russian cargo ship Progress 78 were able to counteract the misfire.

Cosmonauts Pyotr Dubrov and Oleg Novitsky monitor the arrival of the Nauka module from inside the International Space Station on July 29, 2021. (Image credit: ESA/NASA–T. Pesquet)

Novitsky and Dubrov resumed preparations for opening the hatch today. In the long term, the module will also require a series of as many as 11 spacewalks to fully prepare for its duties, according to NASA spokesperson Rob Navias during a live broadcast of Nauka’s docking. The two cosmonauts will begin those procedures in early September.

In response to the loss of attitude control, NASA canceled remaining scheduled astronaut activities and postponed the launch of Boeing’s uncrewed Starliner test flight, OFT-2, that had been scheduled to blast off toward the space station today. The launch will now occur no earlier than Tuesday (Aug. 3).

Email Meghan Bartels at or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.


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