09:01 AEDT Thu 15 Mar 2001 Mission Control braces for Mir glitches

With just a week to go before the scheduled dumping of the Mir space station, Russian space officials have admitted its fiery landing in the South Pacific may not be as smooth as planned.

The chief of Russian Mission Control acknowledged low batteries and failure of the central computer could hinder the landing, despite Russia's substantial experience in bringing spacecraft to Earth.

"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 is to be brought down in a fiery but controlled plunge into the South Pacific in a delicate series of manoeuvres tentatively set for March 21-22.

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 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 dropped to 220 kilometres (132 miles).

Then, if everything went according to plan, a cargo ship docked to the station will fire its engines twice during two consecutive orbits and then, several hours later, fire again to send the station down 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 would adjust it using the cargo ship, which has its own computer and radio line, Solovyov said.

All manoeuvre 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 defence chief to cancel a trip to Washington scheduled for next week.

Solovyov reasserted that Mir's descent would jeopardise 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 25 tonnes are expected to make it to the Earth's surface.

Despite all pledges from the Mission Control that it could control the descent, the Russian space agency has insured Mir for $US200 million ($A398.8 million) against any possible damages.

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

http://news.ninemsn.com.au/sci_tech/story_2702.asp

-- Martin Thompson (mthom1927@aol.com), March 14, 2001

Answers

MY APPREHENSION WITH THE MIR LANDING IS THAT NOTHING OF THIS MAGNITUDE HAS EVER BEEN DONE BEFORE, MAKING IT A BIGGER RISK. I DO NOT TRUST RUSSIA AFTER THE KURSK DEBAUCLE, AND CHERNOBYL AMONG OTHER MESSES THEY HAVE CREATED. I AM GLAD WE ARE HELPING THEM WITH OUR EQUIPMENT AND KNOWLEDGE, I HOPE IT IS ENOUGH, AND RUSSIA HAS BEEN FORTHRIGHT WITH US! I PRAY FOR AUSTRALIA AND THE PACIFIC. BLESSINGS jUDY

-- Judy Whalen (judywhalen@aol.com), March 14, 2001.

ummm...Judy...you might want to widen your sphere of distrust a bit...may I remind you of another recent submarine debacle, plus a few misplaced bombs here and there?

-- Rachel Gibson (rgibson@hotmail.com), March 14, 2001.