ISS Incident Was Worse Than NASA Reported

Nauka module docked at the International Space Station. (Credit: Roscosmos)

The New York Times reports that the incident last week when the new Russian Nauka module on the International Space Station unexpectedly fired its thrusters was far worse than NASA reported last week. The rotation of the station went far beyond 45 degrees. NASA Mission Control Flight Director Zebulon Scoville told The Times:

In an interview, Mr. Scoville described how the International Space Station spun one-and-a-half revolutions — about 540 degrees — before coming to a stop upside down. The space station then did a 180-degree forward flip to get back to its original orientation...

The new Russian module is docked on the underside of the space station. When Nauka tried to move, it pulled down the rear of the space station, and the front pitched upward. “It’s exactly like doing a back flip,” Mr. Scoville said.

The rate of rotation reached a maximum of 0.56 degrees a second, Mr. Scoville said. That spinning is not nearly fast enough to generate significant artificial gravity — he said the astronauts reported almost no noticeable change in conditions within the station.

After about 15 minutes, Nauka’s thrusters petered out. Mr. Scoville said he did not know why, although reports said the module had used up its propellant. The mission controllers could then more easily bring the station to a halt. “After doing that back flip one-and-a-half times around, it stopped and then went back the other way,” Mr. Scoville said.

A key problem was the newly arrived module could only be controlled from the Russian mission control center. The ISS crew couldn’t shut down the thrusters on their own.

Roscosmos has attributed the incident to a software problem.