NASA officials confirmed that the International Space Station (ISS) lost contact with Houston’s Mission Control for just under 3 hours on February 19.
NASA spokesman Josh Byerly said that something went wrong around 9:45 AM EST during a computer software update on the station and ISS abruptly lost all communication, voice and command from Houston.
Flight controllers were in the process of updating the station’s command and control software, transitioning from the primary computer to the backup computer, when the loss of communication occurred. Mission Control was able to communicate with the crew only when the space station flew over Russian ground stations, just before 11 AM. The crew was instructed to connect another computer and begin the process of restoring communications. Communication with the station was eventually restored at 12:34 PM. ISS Commander Kevin Ford reported that the station’s status was fine and that the crew was doing well.
NASA communicates with and sends commands to the station from Houston’s Mission Control via three Tracking and Data Relay Satellites that transmit voice, video, and data. It seems the disconnect may have occurred when transmission was supposed to transition from one satellite to the next, as a result of an updated system not yet being loaded with the proper access codes. The last time ISS communications were interrupted the culprit was road work in Moscow that accidentally severed a cable cutting Russia’s communication links with its space segment on November 15, 2012. That time, communications with the International Space Station were routed through Houston for the duration of the inconvenience. Before that, ISS lost command and voice link with Houston for a few hours due to a failure in the Front-End Processor, on July 1, 2012.
Although today’s event was not part of the testing, Byerly reported that in the past few weeks the space station had been purposely simulating a future Mars mission, considering communications delays and downtimes to see how activity could be carried out in absence of mission control.
Below, the ISS update for February 19: