Russian cosmonauts on the orbiting Mir space station have replaced a computer which had been causing problems with the power supply.

Flight control said a new computer, brought aboard earlier this year, had been successfully installed in its place and was being downloaded with data.

The fault had prevented the proper orientation of the space station, designed to keep its solar panels aligned with the sun.

But a spokesman said Mir's positioning had not been badly affected.

The Americans are due to launch a shuttle craft on Tuesday to rendezvous with Mir.

It will be the last American mission to Mir before the space station is taken out of service.