THE pride of the Russian space programme exploded in the Earth's atmosphere yesterday showering the Pacific Ocean with tonnes of debris. Watched by a motley crew of cardigan-wearing Russian scientists at mission control, it was a miracle the destruction of Mir had gone to plan - and an even bigger one that it had stayed in orbit for so long.

"Mir has finished its triumphant flight," said one of the scientists, after witnessing the space station break into six luminescent pieces the size of double-decker buses, on the oldest television screens imaginable.

Mission control officials had carried out 50,000 computer simulations of the descent in a bid to ensure a successful end to the hit-or-miss salvage job. Luckily, three bursts of the rocket motors aboard the 143-tonne scientific platform were sufficient to push it into a downward trajectory which would see it splash down miles away from populated areas, into the South Pacific, near Fiji.

Mir was well past its sell-by date, ten years to be precise. But unlike the other 18,000 pieces of space junk floating around the Earth, it was too big to leave alone.

As solar flares millions of miles away on the surface of the sun influence the Earth's atmosphere, causing it to swell, Mir was in danger of being dragged from its low orbit of about 140 miles by the upper limits of the stratosphere, with potentially disastrous consequences. So the decision was taken to plot its demise - and just in case the experts got their sums wrong, they took out a £135m insurance policy for damages.

It didn't and now Mir is no more, save a few tonnes of scrap at the bottom of the sea, to be lamented by the countless cosmonauts who inhabited it over the past 15 years.

When it was launched on February 20, 1986, Mir was at the forefront of space exploration and represented a major technological coup for Russia. Since then it has circled the globe more than 80,000 times, at a cost of £156m a year.

During the first five years - its original lifespan - cosmonauts and scientists pushed back the limits of knowledge on the physics of active galaxies, quasars and neutron stars, and acquired a wealth of information about living for long periods in space. Mir played host to 28 long expeditions, 16 shorter ones, and around 23,000 scientific experiments. The station was almost permanently occupied, apart from a few months in 1989, until it was abandoned in August 1999. Crew members set records for living in space, with Valeri Polyakov staying aloft an unbeaten 439 days.

The space station consisted of six modules, providing habitation, laboratory and storage facilities. To make crew members feel at home, the "living zone", in the core Mir module, had distinct floors, walls and ceilings, in pastel shades of green, despite "up" and "down" having no meaning in zero gravity. Visiting American astronauts were surprised to find carpets, coloured walls and furniture. But they also had to put up with musty smells and rattling radiators struggling to keep out the freezing temperatures of space. Soyuz spacecraft were used to transport crews to and from the space station and a cargo and supply vehicle, the Progress-M spacecraft, ferried equipment.

During the Cold War, military testing was carried out on Mir, as well as astronomical research. That changed with the disintegration of the Soviet Union in 1991 and research turned to such things as rearing quails in a weightless environment and growing wheat.

But it hasn't all been plain sailing, and during the 1990s Mir was plagued by accidents. The most dramatic mishap occurred on June 25, 1997, when British-born American astronaut Dr Michael Foale was on Mir. A Progress supply ship filled with junk removed from the station earlier crashed into the Spektre scientific module. The collision almost sent Mir spinning into oblivion. Foale, who was at the far end of the space station at the time, feared for his life.

Days later, there was another emergency when one of the crew mistakenly uncoupled Mir's main computer, causing the station to start cartwheeling and threatening a catastrophic loss of power as the solar panels were thrown out of alignment. Foale saved the day on that occasion by using a Soyuz escape pod's thrusters to bring the station under control.

In the same year, a series of computer failures caused Mir to shift position and barely miss a passing satellite. Then, in 1998, another computer error resulted in a sudden engine failure. Attempts to make repairs were hampered because the spare parts were the wrong size.

One of the less serious glitches to affect Mir was the first alleged case of sexual harassment in space, when a Russian planted a kiss on the lips of a female Canadian astronaut. And the final straw came last December when Mir controllers lost radio contact with the station for nearly 24 hours over Christmas Day and Boxing Day. A permanent loss of contact could have led to it crashing to Earth out of control.

At the end, the once proud station was more an embarrassment, with mouldy walls, failing airlocks and leaky toilets. Just as it had once encapsulated the might of the Soviet bloc, so it decomposed, crashed and finally burned like the country itself. But at least, like the translation of its name, Mir is now at "peace".