Sometime next year, a cargo ship docked to Mir will fire its rocket engine one last time and send the deserted space station on a suicidal dive over the North Pacific.
For NASA, the end can't come quickly enough.
With shuttle visits almost over, U.S. space officials want over-the-hill Mir out of the way so their Russian counterparts can devote their scarce resources to the stalled international space station.
At NASA's prodding, the Russian Space Agency recently agreed to begin preparing for Mir's impending demise. But the two sides still are haggling over when to pull the plug.
The Russian Space Agency is targeting December 1999 for Mir's searing plunge through the atmosphere. It's reluctant to give up Mir until the international space station is inhabited.
NASA, however, is pushing for a July 1999 exit.
The way NASA sees it, the Russians cannot afford Progress cargo ships and Soyuz manned capsules for two orbiting stations. Something has to go, and that something is Mir.
"We have to be real careful. It's a sensitive subject," said Keith Reiley, a space station manager. "Storming into a meeting and saying 'We want you to kill your station' is not a good way to do it."
"It's a resource problem," he added. "We're concerned [that] if there is a problem, ISS will get the short end of the stick," ISS being the International Space Station.
The issue is so emotionally charged that the Russians wouldn't even talk about their plans to bring down Mir until just a few months ago, Reiley said.
"Imagine how we felt when the lunar program was canceled," said Jack Bacon, another NASA manager. He noted, however, that nothing lasts forever, not a '52 Chevy or the '86 Mir.
"At some point you've got to trade it in," Bacon said.
Acutely aware of their financial limitations, the Russians have sought NASA's help to bring down Mir; a space shuttle not only could help lower Mir's orbit but bring back a load of Mir memorabilia. NASA's response? Nyet.
Station program manager Randy Brinkley said he and others have made it "very clear" that Discovery's launch to Mir last Tuesday to pick up American Andrew Thomas will be the last shuttle visit. The Russians will have to rely solely on Progress cargo ships to bring down Mir, he said.
"You can do as much with a Progress as you can a shuttle, and Progress costs a heck of a lot less," Brinkley said.
Still, the idea of salvaging Mir appeals to astronaut Charles Precourt, commander of Discovery's ferry flight. Wouldn't it be great, he asks, to haul back some Mir modules aboard a shuttle for museum display? Or to somehow boost Mir into an orbit where it could remain indefinitely?
"They're all very technically difficult things to do," Precourt said. "It's just kind of sad that it all vaporizes."
Here is NASA's take on Russia's preliminary plans to vaporize Mir:
Launched a few months apart with fuel, food and other supplies, Progress ships no longer are being used to boost the 250-mile-high station. As a result, Mir already has begun its slow, drawn-out descent thanks to the constant tug of Earth's gravity.
The Progress ships, docked one at a time, will lower one end of Mir's orbit through periodic engine firings over the next year.
The final series of shoves will begin a month before Mir's demise.
By then, the last cosmonauts will be gone and the station will be in a lopsided orbit with the low end about 100 miles above Earth.
A Progress commanded by ground controllers steadily will lower the low end of Mir's orbit. At the same time, the atmosphere will drag down the station even more.
After a month of this, ground controllers will fire the Progress ship's main engine one last time. The braking will slow Mir enough for gravity to catch the 120-ton station and send it crashing down, hopefully over an unpopulated swath of the Pacific south of Alaska but north of Hawaii.
Most of the station should burn up on the way down. Sturdy pieces like fuel tanks may survive, however, thus the remote Pacific locale.
By planning for all this now, NASA hopes to avoid the hype and haphazardness that accompanied Skylab's 1979 fall, which was largely uncontrolled. Nearly one-third of the 78-ton space station survived the intense heat of reentry, and thousands of pieces crashed into the Indian Ocean and onto Australia.
Russian space officials say they won't abandon Mir until the international space station is up and running.
"The decision will be taken only when we will see the first crew on orbit and when we will operate quite normally," said Grigory Ossipov, the Russian Space Agency's representative at Johnson Space Center, the hub of space station planning.
NASA hopes to have astronauts and cosmonauts living in the international space station by next summer, one year later than planned.
First, however, the station has to be launched.
The Russians should have sent up the first station component in November, but the flight was delayed until June because of their inability to complete another part, called a service module.
The June launch date, too, was scratched. Now the first assembly mission is set for November.
The reason for the latest delay is the same as before: The Russian Space Agency doesn't have enough government funds to finish building the crucial service module. More delays could be looming if Russia cannot supply the promised number of Progress and Soyuz ships, said Mark Geyer, a NASA station manager.
Ossipov insists that the international space station is his agency's top priority, not the 12-year-old Mir, already seven years beyond its design lifetime. And he scoffs at the suggestion that he and his colleagues are stalling work on the international space station to keep raking in money from Mir's foreign guests.
NASA's Reiley doesn't buy that either.
"They don't make enough to keep it up, I don't believe, and also it's an old station," Reiley said. "The only thing that's keeping them going are some foreign contracts and pride. It's their station."