Mir splashdown time set

The Mir Space Station will be dumped in the South Pacific on Friday at around 6.30am Irish time.

The Progress cargo ship docked at the station will fire its engines twice during two consecutive orbits to lower the station, according to the Russian space agency.

Several hours later, it will fire one last time to send the station hurtling into the South Pacific between Australia and Chile at around 9.30am Moscow time (6.30am Irish time).

Mission Control officials say they have conducted 50,000 computer simulations of the descent process to make sure that the station's debris lands in the designated ocean area.

Fearing that Mir's unstable batteries could cause the orbiting station's central computer to fail, Mission Control experts have worked out a backup, using the Progress onboard computer and separate radio communications.

Yet, despite their efforts, space officials have cautioned that the descent of the 143-ton station might still defy their expectations.

Nikolai Anfimov, the head of the Central Research Institute of Machine-Building, the leading expert body for the Russian space programme, has acknowledged that there is an outside chance the engines will not supply as much thrust as they should. That could see the station's wreckage overshooting the dump zone.

He said: "If an engine impulse is insufficient, the station will fly farther and the southern tip of South America could be affected."

At the same time, Anfimov sought to allay Japanese fears about the Mir, which will pass over Japan on its way down.

"It will still be so high up that it will pose no threat to Japan," he said.