Bracing For Mir's Descent

By CBSNews.com staff CBSNews.com staff

March 7, 2001 / 12:39 PM EST / CBS

With just a week to go before the scheduled dumping of the Mir space station, Russian space officials tried Wednesday to reassure a nervous public they will be able to control the orbiter's descent, even in case of a power outage or computer failure.

Mir is to be brought down in a fiery but controlled plunge into the South Pacific in a delicate series of maneuvers scheduled for March 21-22. Russia has substantial experience in bringing spacecraft to Earth, but the chief of Russian Mission Control acknowledged this operation may not go as smoothly as planned.

"We anticipate two possible problems -- the batteries running low ... and the central computer's failure," Vladimir Solovyov told reporters at Mission Control in Korolyov, on Moscow's northeastern outskirts.

Mir's batteries are old and unreliable and controllers are allowing the craft to roll slowly as it orbits because keeping it steady could sap the batteries. It has also switched off most of the station's equipment in a further move to conserve power.

Last December, Mission Control lost contact with the station for more than 20 hours because its batteries suddenly lost power. Space officials have managed to retain contact with Mir during several subsequent power losses, but each of those incidents disabled Mir's central computer for several days.

Solovyov said the Mission Control would align the station once its orbit drops to 132 miles.

Then, if everything goes according to plan, a cargo ship that is docked to the station will fire its engines twice during two consecutive orbits and then, several hours later, fire again to send the station plunging into the South Pacific between Australia and Chile.

If a sudden power loss or a skittish computer make it impossible to align the station, Mission Control will adjust it using the cargo ship, which has its own computer and radio line, Solovyov said.

All maneuvers will take place over Russia so that Mission Control can monitor them using Russian radar stations. When Mir heads down into the ocean after the final push, it will descend over China and Japan -- a plan that has made Japan nervous and even prompted its defense chief to cancel a trip to Washington scheduled for next week.

Solovyov reasserted that Mir's descent would jeopardize neither country.

"The station will still be high up while it passes over these countries, and no debris could hit them," he said.

Most of Mir will burn up in the atmosphere, but some 1,500 fragments with a total weight of up to 27.5 tons are expected to make it to the Earth's surface.

Despite all pledges from Mission Control that it could control the descent, the Russian space agency has insured Mir for $200 million against any possible damages.

Solovyov scoffed at recent reports that space fungi clinging to Mir could have mutated and might be dangeous if they reach Earth, calling the reports "ravings." Numerous inspections have found Mir safe and, in any case, all bacteria would burn up on fiery re-entry, he said.