The Russian computers that help keep the International Space Station in orbit were out of commission for the second day, a glitch that could imperil the $100 billion orbiting laboratory if it is not corrected.

NASA officials expressed confidence, however, that the problem could be resolved. “I fully expect us to be able to do this,” said Michael T. Suffredini, the manager of the station program.

The station depends on Russian and American computer systems to maintain the attitude of the station as it orbits the earth. The United States computer system runs the network of gyroscopes that provide stability, and the Russian system controls thrusters that correct the orientation of the station when the gyroscopes alone cannot do the job and shift position for operations like docking and avoiding debris.

The problem first emerged on Tuesday as astronauts were connecting a new 17.2-ton truss to the station. The three navigation computers in the Russian section crashed and could not be rebooted. Thruster control was passed to the shuttle Atlantis, which has enough fuel to provide the attitude adjustment service for several days.