NASA lost communication with the International Space Station today for nearly three hours because of a software update gone wrong. Between 9:45 EST and 12:34 EST on Tuesday, Mission Control in Houston had no contact with the space station. The outage was caused by an update to the International Space Station's command and control software; flight commanders were transitioning from the space station's primary computer to a backup computer to complete a software update when communications gave out.
Houston was able to communicate with the International Space Station during the outage through Russian ground stations, which relayed essential information between U.S. Mission Control and the ISS. Communications between Mission Control and the International Space Station are now back to normal.
Clarification: This article was updated to clarify the role of Russian ground stations during the U.S. communications outage.