NASA lost contact with the International Space Station for about three hours Tuesday during a software update to the ISS flight computers.
At that time, flight controllers in Houston were updating the software onboard the station’s flight computers when one of the station’s data relay systems malfunctioned. The primary computer that controls critical station functions defaulted to a backup computer, but was not allowing the station to communicate with NASA’s Tracking and Data Relay Satellites.
According to Expedition 34 commander Kevin Ford, "the station's status was fine and that the crew was doing well."
The loss of contact was first reported at 9:45 a.m. ET. Communication was restored by about 12:45 p.m. ET, NASA tweeted.
NASA spokesman Josh Byerly said NASA was able to communicate with the space station every 90 minutes, when it passed over Russian ground stations, according to CNN.
Byerly said the station, which currently has two American astronauts, one Canadian and three Russian cosmonauts on board, did not appear to be in danger.
Officials said that though the loss of contact is not unprecedented, it remains a cause for concern, CNN reported.
Chris Hadfield, a Canadian astronaut who currently lives aboard the ISS, tweeted this morning, before the loss in communication:
Good Morning, Earth! Today we transition the Space Station's main computers to a new software load. Nothing could possibly go wrong.
— Chris Hadfield (@Cmdr_Hadfield) February 19, 2013