Russian officials on Friday blamed a “software failure” for the unexpected chain of events that on Thursday sent the International Space Station into a spin and forced the postponement of Boeing’s long-awaited relaunch of its uncrewed Starliner space capsule.
The soccer-field-sized space station had completed about one-eighth of a turn on its axis when ground controllers regained control. NASA officials said they believed the unexpected movement had not physically damaged the station.
A Russian statement quoting Vladimir Solovyov, the flight director of the space station’s Russian segment, called what took place “some modification of the orientation of the complex as a whole.” Joel Montalbano, leader of NASA’s International Space Station program, said the mishap didn’t put anyone’s life in danger.
Still, one expert not involved in the mission said what happened “wasn’t a benign event.”
“On some level, they’re in danger all the time they’re in space,” said Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics. He said that a 45-degree reorientation shouldn’t be a safety issue since the space station is designed to rotate 180 degrees. But other factors could be concerning.
“It’s not the rolling around that’s the problem, it’s the speed at which you do it,” McDowell said. “And when you’re trying to compensate for thrusters on one end by applying forces at a different end, you’re putting bending forces on the joints. It wasn’t a benign event.”
NASA officials at the space station’s control center in Houston said the disruption occurred shortly after a Russian lab module, Nauka, had docked with the station early Thursday. The module unexpectedly fired its thrusters, which shifted the multi-ton station 45 degrees outside its typical orientation.
Personnel aboard the space station launched other thrusters as a counterbalance. This led to a “tug of war” between the ISS, a soccer-field-sized operation, and Nauka, a 42-foot research facility. The incident caused ground controllers to lose communication with astronauts onboard twice, once for four minutes and again for seven minutes. And the turmoil continued until Nauka used up its fuel supplies. The space station was out of position for 47 minutes, NASA said.
The Russian statement gave this account: “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.”
“At the moment, the station is in its normal orientation, all the ISS and the multipurpose laboratory module systems are operating normally,” the Russian statement said Friday. “The crew is now busy balancing the pressure in the Nauka module. This is a rather lengthy procedure.”
The fallout from the thruster debacle threw Boeing’s uncrewed Starliner launch off schedule.
The uncrewed demonstration flight would mark a redo attempt by Boeing to kick-start a commercial astronaut business.
Delaying the mission gives the space station team time to “ensure the station will be ready for Starliner’s arrival,” NASA said in a statement Friday.
Starliner’s road to the ISS has been a $5 billion, multiyear journey plagued more recently by software issues, a management shuffling, a failed first launch attempt and a NASA probe. Nauka’s journey to the space station was riddled with 10 years of setbacks, including funding issues and technical problems.
If the coast is clear on Tuesday, Starliner will travel more than 200 miles and arrive at the space station within 24 hours. It will come back to Earth after a few days carrying cargo for NASA. If successful, the feat will prove to the space agency that Boeing’s spacecraft is fit to ferry astronauts back and forth.
Boeing and NASA say the capsule and its corresponding rocket “are in a safe, flight-ready configuration and do not require any near-term servicing.”
Boeing hopes to proceed with crewed missions by the end of the year.
