The ISS lost communication with the ground around 9:45 a.m. EST, NASA officials said in a statement. It was restored about three hours later at 12:34 p.m.
The lost communication link is being attributed to a computer glitch.
One of the station's data relay systems malfunctioned as Houston controllers were updating software on the station's main computer.
"The loss in communications is not considered unprecedented, though it's considered a cause for concern," CNN reported, citing officials.
Initially, the ISS crew could only communicate with the space agency every 90 minutes as the spacecraft moved over Russian ground stations.