|Russia's space chief has acknowledged the Phobos-Ground mission was ill-prepared [Reuters]
A failed Russian probe designed to travel to Mars but stuck in Earth's orbit has crashed into the south Pacific Ocean west of Chile's coast, Russian media reported authorities as saying.
Pieces of the Phobos-Grunt craft fell into the sea some 1,250 km west of the coastal island of Wellington at 1745 GMT, Colonel Alexei Zolotukhin, a spokesman for the aerospace defence forces was quoted as saying.
It was not immediately clear whether all debris from the craft fell at that location.
The $170m Phobos-Ground was Russia's most expensive and most ambitious space mission since Soviet times. The spacecraft was intended to land on the Martian moon, collect soil samples and fly them back to Earth, giving scientists precious materials that could shed more light on the genesis of the solar system.
The Russian spacecraft went off course after reaching Earth's orbit [File: Al Jazeera]
A large part of each orbit is over water, and scientists have estimated that the risks of the probe crashing into any populated areas are minimal. Thousands of pieces of derelict space vehicles orbit Earth, occasionally posing danger to astronauts and satellites in orbit, but as far as is known, no one has ever been hurt by falling space debris.
At 13.5 metric tons, the Phobos-Ground is one of the heaviest pieces of space junk ever to fall on Earth, and one of the most toxic too. The bulk of its weight is a load of 11 metric tons of highly toxic rocket fuel intended for the long journey to the Martian moon of Phobos. It has been left unused as the probe got stuck in orbit around Earth shortly after its November 9 launch.
By comparison, NASA's Skylab space station that went down in 1979 weighed 77 metric tons and Russia's Mir space station that deorbited in 2001 weighed about 130 metric tons.
Roscosmos predicts that only between 20 and 30 fragments of the Phobos probe with a total weight of up to 200 kilogrammes will survive the re-entry and plummet to Earth. It said all of the fuel will burn up entirely in the atmosphere.
Russia's space chief has acknowledged the Phobos-Ground mission was ill prepared, but said that Roscosmos had to give it the go-ahead so as not to miss the limited Earth-to-Mars launch window.
The worst ever radiation spill from a derelict space vehicle came in January 1978 when the nuclear-powered Cosmos 954 satellite crashed over northwestern Canada. The Soviets claimed the craft completely burned up on re-entry, but a massive recovery effort by Canadian authorities recovered a dozen fragments, most of which were radioactive.
The Phobos-Ground also contains a tiny quantity of the radioactive metal Cobalt-57 in one of its instruments, but Roscosmos said it poses no threat of radioactive contamination.