Krikalev and astronaut Nancy J. Currie replaced a faulty unit
Sergei Krikalev, mission specialist representing the Russian Space Agency (RSA), pokes his head up from inside one of the bays inside the walls on the Russian-built Zarya module December 11, 1998. Krikalev and astronaut Nancy J. Currie replaced a faulty unit which controls the discharging of stored energy from one of Zarya's six batteries. (photo by NASA)