Bringing Mir Down

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Bringing Mir Down Warren E. Leary New York Times Service Thursday, March 15, 2001

WASHINGTON After much speculation and many delays, Mir is finally coming down - hard, hot and soon.

The massive Mir space station, one of the most successful space ventures in history, is to end 15 years of circling the earth in about a week. With final nudging from the rockets of an attached cargo ship, Mir will dive into the atmosphere in a last, searing display of bravado, its blazing remains heading for an isolated target spot in the South Pacific.

The space station, which was a pinnacle in the space program of the former Soviet Union and a source of pride in Russia, has been slowly sinking into lower orbits for months. In January, Russia sent an unmanned Progress cargo ship with extra fuel to Mir to guide it on a final controlled plunge into the ocean.

Mir, weighing more than 135 tons with all its connected modules and parts, will be the largest object ever brought down from space. Most of the station is expected to burn up as it enters the atmosphere, but 20 to 25 tons will probably continue to plunge toward the earth, including chunks weighing hundreds of pounds. Russia has spent months planning the descent and assuring the world that it can be done safely.

Last week the Russians changed their plan for bringing down Mir, which is in an orbit about 150 miles (250 kilometers) up and dropping more than a mile a day as atmospheric drag slows it. Instead of taking Mir out of orbit at the 150-mile altitude, as originally planned, they decided to let the station continue to descend ever faster and begin a series of rocket firings to guide it in when Mir reaches an altitude of about 137 miles.

"Mir's de-orbit is tentatively set for March 20, give or take a day," said Viktor Blagov, deputy chief at Russia's mission control in Korolyov, near Moscow. Waiting until the station is closer leaves more fuel for the final maneuvers, officials said.

On Mir's final day in space, controllers plan to stabilize the slowly rolling station before the attached Progress freighter fires its engines at least twice to push the low point of the spacecraft's orbit deeper into the atmosphere at a point above the target area. When the station is aligned with its target, the Progress will perform a long final engine burn to drop Mir out of orbit and into the atmosphere at a steep angle toward its target in the Pacific.

Mir is now so close to the earth that scientists predict it would have come down on its own at the end of the month in an uncontrolled plunge somewhere along its flight path, which covers 80 percent of the planet. The Russians have worked hard to avoid this potentially destructive alternative and bring Mir down in a safe place.

Mir's remains are supposed to come down in the Pacific in an area 1,850 miles east of the southern tip of New Zealand, a region with no islands and little air and sea traffic. The debris is supposed to fall in an elliptical "footprint" midway between New Zealand and Chile, a target area perhaps 1,000 miles long, and about 120 miles wide at the beginning, tapering down to 20 or 25 miles at the end.

The Mir complex consists of a large core launched in 1986 and five major laboratory and systems modules attached over 10 years. Also aboard is a docking compartment for visiting American space shuttles and the Progress freighter. Four of the laboratory sections are attached at right angles to the core like a clover leaf and most of the segments have winglike solar panels.

As Mir dives into the atmosphere, experts said, aerodynamic forces will first strip off the solar panels and thermal radiators of sheet aluminum, which should flutter to the ocean. Ruptures caused by parts tearing off and air friction generating heat as high as 3,000 degrees will probably cause the pressurized modules to break loose and explode, creating a display of smoking, incandescent fragments plummeting through the sky.

Experts expect 40 propellant tanks, many large batteries, metal storage boxes and heavy metal bulkheads to survive re-entry to hit the ocean at the narrow end of the target area at speeds of up to 150 miles an hour. Some lighter debris, possibly including clothing and insulating foam, should float down into the broad end of the impact zone.

Nicholas Johnson, chief scientist for orbital debris studies at NASA's Johnson Space Center in Houston, and other experts say the Russians have more experience bringing down used spacecraft than anyone else. Since 1978, they have taken five early Salyut space stations and 80 Progress spacecraft out of orbit in the same Pacific area, Mr. Johnson said.

"The most recent space station to descend over the Pacific was Salyut 6," he said. "That weighed 40 tons and came down in July of 1982. The deorbiting technique is exactly the same. Mir's just a bit bigger."

While experts are confident that the Russians can bring down Mir as planned, there are concerns. Japan, Australia and New Zealand, near Mir's final orbit, have set up monitoring groups that could rush aid to citizens should debris hit their countries. Last week, the 16 states of the South Pacific Island Forum, including Papua New Guinea and the Cook Islands, asked Russia for assurance that debris would not threaten them.

To help relieve this anxiety, the Russian Aviation and Space Agency took out a $200 million insurance package with three Russian companies, backed by Western insurance syndicates, to pay for any damage by Mir.

History shows some reason for concern when large spacecraft come down, though none are known to have caused serious injuries, deaths or major property damage.

When Mir's predecessor, Salyut 7, re-entered on Feb. 7, 1991, Soviet ground controllers ran low on fuel and tried to direct the 80,000-pound (36,000 kilogram) craft into the Atlantic Ocean by putting it into a tumble. The maneuver failed and Salyut 7 came in over Argentina, scattering debris over land.

Perhaps the most memorable re-entry was that of the first American space station, Skylab, on July 11, 1979. NASA engineers had limited control over the 165,000-pound station, which had no rockets to guide it in.

Controllers changed the Skylab's orientation in space to increase or reduce atmospheric drag to shift its entry point. Skylab fell into the Indian Ocean, as NASA predicted, but the craft proved sturdier than engineers had predicted and did not break up as quickly as forecast. Pieces traveled farther than expected, falling harmlessly in Western Australia.

William Ailor, director of space debris studies for the Aerospace Corp. in El Segundo, California, said the chances were quite small that a person would be hurt by space debris, which is constantly raining in, unnoticed by most people. The risk of being hurt by a piece of a falling spacecraft is about one in a trillion, he said, compared with the 1 in 1.4 million chance of being hit by lightning.

But Mr. Ailor said Mir's controlled re-entry still posed risks because so many things could go wrong, like engine misfirings, the station tumbling too much or too little in its final stages or coming apart in an unexpected way. "Everything has to go right for this to work as designed," he said. "A lot of things can happen in the lower atmosphere that you can't predict."

Because Russia can track Mir only when it is over its territory, Moscow has asked the United States and Europe to monitor the space station's descent as well. The U.S. Space Command, which monitors 8,300 earthly objects in space from its headquarters in Cheyenne Mountain, Colorado, will use radar and telescopes to provide Russia with information about Mir's trajectory, and about atmospheric conditions. Major Perry Nouis, a spokesman for the command, said the data would be fed to the Johnson Space Center, which would then relay it to the Russian control center using high-speed links set up between the two for the International Space Station.

The American tracking information will also be fed to the Pentagon's National Military Command Center, where it will be shared with the White House and interested agencies, including the Federal Emergency Management Agency, the State Department and the Federal Aviation Administration.

Copyright 2001 The International Herald Tribune

http://www.iht.com/cgi-bin/generic.cgi?template=articleprint.tmplh&ArticleId=13455

-- Martin Thompson (mthom1927@aol.com), March 15, 2001

Answers

Good article. Regarding the "mutant fungus" concerns:

Unnamed experts are indirectly quoted to the effect that temperatures will reach 3,000 degrees -- I add: *if* this is accurate and afects all components, such heating would sterilize any nasty bugs aboard.

I am amused that Celsius versus Farenheit isn't mentioned. Not that it matters, for biological sterilization. To quote a favorite line from the TV cartoon "Futurama,": a character was asked whether a certain temperature was degrees C or degrees F, and he replied, "First the one, then the other." True, and adequate.

-- Andre Weltman (aweltman@state.pa.us), March 15, 2001.


8:50 AM 3/15/2001 Russia's Mir to splash down March 22 AFP MOSCOW, March 15 - The Russian space station Mir will fall to Earth "around 0800 GMT" (2 a.m. CST) on March 22, Russian space officials said Thursday.

It was the first time such precise timing had been given for the splashdown of the platform, whose destruction was announced last year.

The Mir platform will splash down into the Pacific Ocean "around 0800 GMT," a spokesman for the Russian mission control center (TsUP), Vsevolod Latychev, told AFP.

On the night of March 21, Russian mission control will direct a rocket engine to fire three short bursts, causing the platform to tilt and re-enter the atmosphere. Mir is then to burn up and debris will rain down on the South Pacific sea.

The target area between New Zealand and Chile is 200 kilometers (120 miles) wide and 6,000 kilometers long, Latychev said.

Technician Viktor Blagov said Mir would fall "between 46 and 48 degrees latitude south," its descent lasting "around 40 minutes."

TsUP officials said that Mir's altitude was currently 238.5 kilometers, with the final descent due to be triggered once it reaches 220 kilometers.

Around 20 tons of the platform's 137-ton mass are expected to survive the burn-up, with 1,500 pieces of debris, mostly very small but a few of them as large as a small car, falling to Earth.

Experts have warned of the operation's immense complexity -- no object the size of Mir has ever been brought back to Earth before -- and governments on five continents have expressed concern at the possibility of debris crashing into their backyards.

Russian officials are stressing that the chances of debris falling on inhabited areas are minimal.

However, the Russian space center has taken out insurance for 200 million dollars to cover possible damage.

http://www.chron.com/content/interactive/space/missions/mir/news/2001/ 20010315.html

-- Martin Thompson (mthom1927@aol.com), March 15, 2001.


Up to 20 US fishing boats in Mir splash down area

Source: AFP|Published: Friday March 16, 9:24 AM

AUCKLAND - Up to 20 mainly American fishing boats were in the area where Russia plans to crash its space station Mir next week, a fishing science source said today.

Mir is due to come down next week in an area of the South Pacific centred around 140 degrees west, 47 degrees south, 4,000 kilometres east of here.

The area is known as Navarea XIV to maritime authorities who, through New Zealand, last week issued a "Notice to Mariners" warning of the "re-entry and breakup of the Russian Space Station".

The return coincides with the South Pacific albacore season and around 30 jigboats are operating out of Pago Pago, American Samoa, operating south of 40 degrees south and between 120 to 160 degrees west.

A number of the boats have already returned to Pago Pago with their catches and the source said there were now around 15 to 20 boats in the area.

http://www.theage.com.au/breaking/0103/16/A29811-2001Mar16.shtml

-- Martin Thompson (mthom1927@aol.com), March 15, 2001.


I have recently read that March 20th is the true last day of the Millennium. According to ancient calendars, the 20th of March marked the last day of the year and the 21st of March, the Spring Equinox, marked the 1st day of the new year. In this case, the first day of the new Millennium.

I don't know why, but I get a bad feeling when I think of Mir crashing on the 21st; you know that churning stomach feeling. . I'm not the worrying type, so I can't really explain it.

-- meg davis (meg9999@aol.com), March 15, 2001.


Canoe

Thursday, March 15, 2001

Tourists to fly towards Mir crash site Russia's space agency director compares trip to suicide jump By ANDREW KRAMER-- The Associated Press

MOSCOW (AP) -- After reluctantly deciding to dump the aging Mir space station, Russian controllers chose a spot for re-entry along a swath of the South Pacific, far, far from the nearest inhabited land.

But it's not off-limits to determined tourists.

Herring Media Group, a Sausalito, Calif.,-based public relations firm, has chartered a plane for space enthusiasts and television crews to fly to the site -- a trip Russia's space agency director compares to a suicide jump off a bridge.

Organizers claim the flight is safe, and want to film the spectacle of burning space station debris streaking toward Earth. The 143-ton cluster will be the largest man-made object ever to enter the atmosphere.

Once the pride of the Soviet Union, Mir is scheduled to come down March 22 in a target zone about halfway between Australia and Chile, according to Russia's Mission Control.

More than 50 people have paid about $6,500 each, slightly more for a window seat, to see the historic event, according to company director Marc Herring. The price includes a few nights on the Pacific Island of Fiji before and after the show, a steak barbecue to honor Herring's Texas roots, drinks on the plane and a promised "bash" once the station is down. Four Russian cosmonauts will be on board to see the fiery death of their former home in space, which they dubbed an "apartment."

"We'll see a bright, meteor-like object on the horizon with a smoke trail coming toward us, then a series of explosions of the pressurized vessels and a glow as the station fragments into multiple parts and rains down," Herring said.

Russian Aerospace Agency Director Yuri Koptev maintains any trip to the target zone would be foolhardy, stressing that the area was chosen to minimize risk to people and property on Earth. Still, the space agency can't stop people from going there.

"People used to kill themselves by jumping from the Brooklyn Bridge," Koptev said. "Apparently these people are driven by a spirit of adventure, but we would recommend that they not go there."

But Herring said the plane, either a jet or a turboprop, should never be closer than about 200 miles from the falling space junk.

A navigator will call Russian Mission Control on a satellite phone minutes before the station breaks up, when the final re-entry coordinates are known, and the pilot can skedaddle out of range if necessary, he said.

"It's the sort of thing you shouldn't try at home," Herring quipped.

The unoccupied station still contains a guitar cosmonauts strummed to pass time during their record-setting long stays in space. Russian Orthodox icons adorn the walls, just as Russian ships were decorated in past centuries. The station carries a library of more than 400 books, including Russian classics, detective stories and technical manuals.

These items will likely incinerate in a puff in the upper atmosphere, but about 1,500 chunks of metal weighing a total of about 27.5 short tons are expected to survive re-entry, according to Russian space officials.

When the unoccupied U.S. Skylab space station fell to Earth in 1979, debris came down on a sparsely populated area in western Australia, creating sonic booms and whirring noises audible to people on the ground as it fell. No one was hurt.

Web chatrooms are buzzing with comments on Mir's demise. One contributor asked if anybody had purchased "Mir insurance," recalling that Skylab insurance was sold in the 1970s. Another much-discussed topic: dangerous microbes on the station spreading to earth.

Molds and bacteria live on the station, and one particularly virulent strain has corroded Mir's windows. But the germs pose no danger to Earth's environment, Russian space officials say.

In the months before the Skylab's demise, two American computer specialists established a firm called Chicken Little Associates, offering to predict, for a fee, the likelihood of the station hitting a particular house or point on the Earth's surface. The chances were all minuscule.

This time around in Moscow, the Troika Dialog brokerage, which usually places bets on the gyrations of the Russian stock market, is sponsoring a contest to guess how close the Mir will come to the hometown of one its chief analysts, Tom Adshead, from Christchurch, New Zealand.

New Zealand is not under the station's flight path, and the brokerage stressed the contest was in jest.

-- Rachel Gibson (rgibson@hotmail.com), March 15, 2001.



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