NASA lost communication with the International Space Station [3] 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 [4]. 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 [5], 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.

[Image: NASA]

Clarification: This article was updated to clarify the role of Russian ground stations during the U.S. communications outage.