July 29, 2021: Just 2 hours and 16 minutes after docking of the Russian Nauka module to the ISS, unplanned firings of thrusters on the module caused the ISS attitude control system to stop maintaining orientation in an event called a Loss of Attitude Control (LoAC).
At the time of this event, Odyssey employees Nick O’Dosey and Chris Cederberg were supporting in the Chris Kraft Mission Control Center. Nick was the Attitude Determination and Control Officer (ADCO) who verified and reported the LoAC. Meanwhile Chris, in the position of HAWKI, supported from the backroom by monitoring and reporting key parameters.
Nick and Chris led the ISS flight control team to reconfigure the ISS* so that the Russian Service Module (SM) thrusters could be used to restore the ISS attitude. After about 20 minutes, the Nauka thrusters stopped firing, and the SM thrusters were able to restore the ISS to its nominal attitude. During the event, the ISS exceeded its nominal attitude by about 540 degrees.
This was a very significant anomalous event for the ISS that was resolved with no damage to the ISS thanks to the quick thinking and actions of Nick and Chris. Great job to Nick, Chris, and the entire ISS flight control team on a safe and successful LoAC response and recovery!
*The ISS must be configured in certain ways during thruster firings in order to avoid damage to ISS components.
