So what happened when an uncrewed Russian spacecraft inadvertently fired its thrusters sending the International Space Station tumbling 1½ times about 227 miles above the Earth?
One Durango business, Agile Space Industries, a designer, tester and manufacturer of the thrusters used to steer spacecraft, is uniquely situated to comment on last week’s ill-timed thruster firing.
“Roscosmos claimed it was a short-term software error, which is a funny way to describe it,” said Lars Osborne, propulsion engineer lead for Agile Space Industries. “But my understanding is that the Nauka module got confused into thinking that it was trying to depart the International Space Station.”
Agile, founded in 2009, originally offered a test site for rocket engines in a remote area adjacent to Durango-La Plata County Airport. It expanded in 2018 to design, develop, test and manufacture small rocket engines, called attitude control thrusters, used to steer space vehicles.
Agile was selected in December 2020 by Astrobotic Technology Inc., a Pittsburgh-based spacecraft and space robotics company, to build the 12 thrusters that will guide its Griffin Lunar Lander to the moon.
Griffin Mission One is slated to carry the VIPER, the Volatiles Investigating Polar Exploration Rover, to the South Pole of the moon in late 2023 in search of lunar water and ice.
Thrusters on other modules attached to the ISS were successful in regaining orientation and stabilizing the station, but Osborne said that did not happen without costs.
“Certainly, one of the immediate impacts was all the scientific research that was happening on the International Space Station had to come to a very abrupt halt,” Osborne said. “It will take some time before they can be back into normal operations and resume scientific experiments.”
The inadvertent thruster fire from the Russian Nauka multipurpose vehicle also left the ISS in slightly different orbit, and Osborne said a new maneuver is planned in about two weeks to bring the space station back into correct orbit.
A spacecraft emergency was declared, and Osborne said that required seven people aboard the ISS to prepare for possible evacuation.
The ISS, Osborne said, also briefly went “power negative,” meaning the solar panels were pointed in the wrong direction, and the ISS was draining its batteries.
One final consequence of the ill-timed thruster firing was a delay of the launch of an uncrewed Boeing Starliner capsule to the ISS.
Further problems have been detected with the Starliner propulsion-system, and a new date for launch has not been set.
Osborne credited ground crews.
“Ground controllers did a fantastic job. They were cool under pressure in recovering from this situation, but it was a challenging thing for them to do quickly, and to go from everyday routines to responding to an unusual and unique emergency situation.” he said. “They had to fire up thrusters on another visiting spacecraft in order to try to regain control.”
Osborne said he doesn’t have the detailed data to know exactly what happened, but his understanding is that Nauka’s thrusters could not be turned off until the ISS was over Russia, where it could get a direct satellite radio link.
“So the situation was resolved when it ran out of rocket propellant,” Osborne said.
Russian officials have talked about delinking their modules from the ISS to form the initial components of their own space station.
But the mishap now leaves the Russians without enough propellant to do that, he said.
It’s unlikely that an American spacecraft would have suffered from the same fault as the Nauka because American safety requirements and vehicle redundancies are higher.
“We do have rigorous rules and requirements for American vehicles that visit the International Space Station where those vehicles have to be three-fault tolerant to prevent just this kind of thing from happening,” Osborne said.
Operation of the ISS is guided by a treaty, and NASA does not control quality-control for Russian vehicles.
“So there was no NASA oversight, because this was a Russian module,” Osborne said.
He added: “I think there may be some political implications as well. We'll see. I don’t think I could comment on that.”
Osborne called the mishap a “significant event in spaceflight safety” and said it will be studied for some years.
“I’m sure there are lessons to learn from it,” he said.
Osborne said he’ll be looking for more information about the ill-timed Nauka thruster firing.
“When there is more public information available,” he said, “I will certainly read it to learn more about what happened and how the issue was handled.”
parmijo@durangoherald.com
